We always try to stay on the right side of the law at dustygizmos but in our never-ending quest for truth sometimes it’s worth the risk of a brush with the judiciary. The truth we’re seeking is simple; what the hell is this Knopp Electronizer all about? Here are the things we know for sure. It is mains-powered. It is housed in a well made, sealed wooden box, and when powered up, what we’ll call a ‘probe’ in the absence of a better name, delivers a tad over 1000 volts -- possibly more -- of electricity to… Well, that is the big question? That and just about every other aspect of its existence and purpose remains an intriguing mystery.

A printed notice on the back panel makes it sound even more mysterious. This threatens legal action against anyone attempting to remove the seals and tamper with it. Needless to say, that ship has sailed.

Opening it up reveals just two ‘active’ components; a mains transformer and a potted black box with two wires going in, from the transformer, and one1.5 metre long high voltage cable coming out. The transformer is used to ‘step’ up the mains voltage from 220 to around 600 volts and since what comes out of the HV cable is, like as not, is over 1000 volts, the box probably contains a simple circuit known as a Cockcroft-Walton multiplier. This is basically a string of diodes and capacitors that doubles or trebles an AC voltage, with the possibility of some extra components to limit the current. This may be responsible for the slightly vague estimate of the output voltage. Conventional voltmeters have problems measuring very high voltages but even our specialist HV meter, which works happily up to 3kV was a bit vague, even though it has an internal resistance of 1 gigaohm, and usually perfectly capable of measuring high voltage, low current sources.

The design of the probe doesn’t really help. As you can see it is made up of two metal wires, around 13 cm long, mounted either side of the HV cable. These are kept apart by heat shrink tubing at both ends. It was tempting to speculate that it might be some sort of medical device. However, the voltage is way too high and the current too low to do anything other than give the recipient a bit of a tingle, even if inserted into the one of the two or three two bodily orifices it would fit into. But let’s not go there and besides, medical equipment tends not to have such jazzy cases and the probe is definitely not sterile... It doesn’t look like a piece of scientific equipment either. If so it would have much more in the way of controls and displays.

My best guess, prompted by the name and design, is that it is all, or more likely the major part of a negative ion generator or ‘ionizer’. These were all the rage a few years ago, and thanks to the Covid pandemic have enjoyed a resurgence of interest. The premise is that very high voltages, 1000 volts or more, generate negative ions that can act as microscopic air purifiers. They do this by attaching themselves to airborne contaminants, such as dust, smoke, even virus particles (it is claimed) and make them stick to the nearest surface. There are plenty of other health claims for negative ions but the jury is still out on many of them. The air-cleansing claim is certainly plausible, though. Back in the early 80s, whilst editing a long-forgotten tech magazine called Next… I helped road test a few models and one in particular was demonstrably successful. It produced a thin film of dust around its base whenever it was switched on. However, the surface area of The Electronizer’s probe seems far too small too be very effective at generating and dispersing negative ions, so if that is what it is then there may have been more to it; some sort of stand or holder at the very least.

I came across The Electronizer in a box of electronic bric-a-brac at a large car boot sale in Dorset a few months ago. The stallholder also had no idea what it was or even where he got it from, but in spite of it’s apparent rarity value he didn’t quibble for one second when I countered his £5.00 asking price with an offer of £2.00. After it passed some basic safety checks for its potential to explode, catch fire or billow smoke it seemed okay to power it up. The front panel light came on and a quick dab of the voltmeter on the wires confirmed my suspicions that lots of volts were present and I was wise to resist the urge to grab hold of the probe… Holding the meter probes a few millimetres from the wire produces a tiny spark, but it was fairly puny, suggesting the current flow is very low and probably non-lethal.

What Happened To It?

Attempts to find out what it is have resulted in dead ends since the company that made it, Knopp Electronic Services, latterly of Braintree in Essex, was apparently taken over in the early noughties. The only verifiable mentions of Knopp I could find on the web were in relation to it starting out as a manufacturer of printed circuit boards. The company that bought was no help either as it too has vanished without trace.

So there you have it, an instrument of torture or an air cleaner. Whilst I’m inclined to the latter I welcome input from anyone who know what it actually is. I’m really hoping it’s something weird or exotic. If it is the business end of a domestic or office ionizer then I also hope someone can tell me what, if anything, is missing so I can have a crack at constructing a new one, to see if it actually works. And on that basis, as previously mentioned, home ionizers are still widely available, there are even ones designed for in-car use. Whether they are effective or not for any of the various claims made for them remains a topic for debate, as does the value of this one. As it stands, without any essential accessories or at the very least, an instruction manual, it’s worth the price of the parts and the nice wooden box, or around what I paid for it, unless, of course someone can enlighten me.

Dusty Data

First Seen: 1989?

Original Price: £?

Value Today: £2.00 (0622)

Features: High voltage generator, ‘probe’, neon power on indicator, 2 x fuses, on/off switch and that’s it…

Power req. 220 volts AC

Dimensions: 223 x 140x 95mm

Weight: 1.5kg

Made (assembled) in: England

Hen's Teeth (10 rarest) 9

Playmates Star Trek TNG Comm Badge, 1992

It is widely accepted by those in the know that the best of Star Trek -- the long-running TV and film franchise -- was the 178 episodes of The Next Generation (TNG) series, which ran from 1987 to 1994. After a slightly shaky start it quickly grew into a hugely popular, full-blown cult, endlessly repeated to this day on broadcast TV and digital streaming services. Like the very first series (1966 – 1969) TNG was strewn with weird spacecraft, funky gadgets, dodgy scenery and props and wacky makeup and costumes that rapidly helped TNG to achieve iconic status especially with the hard core fans or Trekkies.

One of the most instantly recognisable and well used of those props, appearing in just about every episode was the standard-issue Starfleet Comm Badge. As the name implies it was two-way communications device, worn on the Enterprise crew’s uniforms. Along with Phaser pistols and Tricorders it was one of the must-have accessories for anyone from fans, young and old, to collectors and of course the Trekkies. Countless versions of the badge were, and still are being produced but for the most part they are just inert decorative items. This one though, approved by Paramount Pictures and made by Hong Kong based toy company Playmates, was different; it actually worked, well, sort of…

You too could be Captain Picard or Commander Data, calling for a beam-up or summoning help by lightly tapping the shiny spaceship motif in the middle of the badge. It produces a satisfyingly realistic trilling sound and as an added, though not strictly authentic bonus, the spacecraft’s nosecone lights up with an eye-catching red glow.

The only let-down is the size, and in particular the thickness, which at 24mm makes it a good deal fatter than either the original TV series prop, or the many, many reproductions. But all is forgiven when you press the call button. It’s just shame they didn’t go just a little further and squeeze in the guts of a small walkie-talkie, and it could have been done because at around the same time you could get a pair of wristwatch size communicators for not a lot more than you would have paid for the Playmates Comm Badge. There’s not a lot to see inside the badge. A handful of components, including the sound generator chip, switch and LED are mounted on a small PCB. The piezo sounder is fixed to the badge’s removable back panel, which also includes the battery holder

This one I discovered recently in a box of old toys left behind by my son Alex, who flew the nest a decade ago. It looked like it had hardly ever been used – he was more into Star Wars. It even came with a pair of AG13 button cells inside the battery compartment, which by some miracle hadn’t leaked. They were, of course, as dead as doornails. Popping in a pair of new cells got it working, though the sound was somewhat stuttery and off key. The problem turned out to be some light corrosion on the battery contacts. It cleaned off easily with a few strokes of a glass-fibre brush and was instantly back on song.

What Happened To It?

A more or less constant stream of prequels, sequels, movies and spin-offs from the original Star Trek series that both excited and angered fans, meant that it never really went away. Nor has the Comm Badge, though it evolved with each new iteration, with small changes in the shape and feature list but the original TNG design has to be the all-time classic and the one to have. It was also the first; Captain Kirk had to make do with a hand held flip-top device that almost certainly inspired early cellphones almost two decades after the first series aired.

Playmates are still in the toy business but I haven’t been able to find out when the TNG Comm Badge first appeared and eventually disappeared. However, there is a copyright notice on this one dated 1992, so it is possible it had been around or in the pipeline for at least a year or so earlier. Production probably continued for a while after the series ended but whatever it’s history when it was on the shelves it doesn’t seem to have been a big seller, especially reliable, robust or sought by collectors. Relatively few appear to have survived, if ebay is anything to go by.

Mint examples, sealed in their original packaging have sold in the past for as much as £100. Clearly this one is not in that league but it is in pretty good shape and would like to think that on a good day, with the wind in the right direction and a couple of determined bidders it might make somewhere between £25 and £50.

DUSTY DATA

First Seen: 1990

Original Price: £15?

Value Today: £30 (1221)

Features: press switch operated sound effect, red LED indicator, belt/costume retaining clip

Power req. 2 x AG12, 1.5v button cells

Dimensions: 90 x 70 x 24mm

Weight: 37g

Made (assembled) in: Hong Kong?

Hen's Teeth (10 rarest) 8

Sharp PA-3100S Electronic Typewriter 1986

With the benefit of hindsight it is easy to see how fast things changed in the 70s and 80s, when it came to the written word. Before then writing was basically something the vast majority of people did with pens and paper. Others learned to type, either out of necessity or because it was a part, or all of their job description. Nowadays we are all familiar with QWERTY keyboard, and even if our typing skills are limited to hunt-and-peck, we get there in the end. It was, of course, all thanks to computers and, more specifically, word processing software, the latter arguably one of, if not the most important developments in human communications since the invention of the printing press.

Word processors go back a surprisingly long way. They have been with us in one form or another for 50 years or more -- depending how they are defined. But before they became so firmly rooted in our culture there was a short transition period when typewriter manufacturers upped their game to compete with the threat from the new technology. The typewriter has also been around for a while, almost 150 years in fact but until the 1960s it had changed comparatively little. Electric motors and actuators made them faster and easier to use but the first really significant change occurred in the early sixties when IBM introduced the Selectric or ‘Golfball’ mechanism. A spinning metal ball replaced Rows of mechanical arms or typebars with characters moulded onto its surface. It moved across the page tapping out characters at high speed and eliminating at a stroke the perennial problem of jammed keys. The really big selling point, though, was that Golfballs could be easily swapped for different fonts and print sizes. Ten years later Diablo Systems launched the Daisy Wheel, a major improvement over the fiendishly complex and expensive Golfball system. Characters are mounted on the end of plastic or metal spokes fixed to a spinning wheel, and because it spun so fast, it required advanced control circuitry. And so began the brief rise and fall of the Electronic Typewriter.

The Sharp PA-3100 shown here dates from the mid 80s. It’s a mains-powered portable housed in a tough carry case with a folding handle. It has a Daisy Wheel printer mechanism but only relatively rudimentary electronics, compared other models on the market, and what was to come. In addition to controlling the Daisy Wheel the electronics provide several extra functions, like the 150 character memory. This is enough for its auto correction system to backtrack the Daisy Wheel and erase up to a single line of text (using a separate spool of white correction tape). It does have a few other tricks up its sleeve, rarely, if ever found on older mechanical or electric typewriters. Like Golfballs a Daisy Wheel can be changed to switch fonts and character sets. It also has adjustable and proportional character spacing, text centering, automated super and subscript printing and single or ‘code’ key formatting options that would otherwise involve a lot of faffing around on a manual or electric typewriter. It uses a disposable carbon film printer ribbon cartridge producing up to 50,000 letter-quality characters for really sharp looking documents. Incidentally, film ribbon cartridges were quite popular for a while until some bright spark pointed out that they had a fatal security flaw. Documents could be easily recovered simply by extracting and literally reading the ribbons from discarded cartridges…

The lack of more advanced word-processing type features was almost certainly a deliberate marketing ploy. It seems clear that the PA-3100 was aimed specifically at typists who, for one reason or another, were not ready or willing to make the big jump to word processing. That’s not as shortsighted as it sounds, as at the time most WP software was decidedly user-unfriendly. It usually required a great deal of training in the dark arts of early computers, most of which had text-based command interfaces. In other words no mice or easy to understand graphical desktops, just lots of codes and keyboard shortcuts to do even the simplest things to the text on (mostly green) monitor screens.

I came across this SP-3100 at a local car boot sale and the outwardly pristine condition, accompanying cartridges and instruction manual prompted me to ask the stallholder how much? It would have been rude to haggle over the £3.00 asking price, and I wasn’t surprised when I got it home to find that it was little used and in perfect working order. My guess was it was either bought by a novice typist, mistakenly thinking ‘Electronic’ meant something more elaborate, or it was a temporary stopgap or backup machine for someone waiting for the price of PCs, word processors printers and software to fall, which it did, really quickly, thanks to the likes of Amstrad, Atari, the BBC, Commodore, Dell, Hewlett Packard and IBM to name just a few of the eighties leading lights.

What Happened To It?

By the early 80s it was blindingly obvious that typewriters, whether manual, electric or electronic were effectively obsolete, but the takeup of word processing -- at the time the only compelling reason to buy a PC -- took almost everyone by surprise. The typewriter market shrunk to almost nothing over the next few years leaving just die-hard and old-school typists, too set in their ways to change. Basic word processing features quickly found their way into electronic typewriters but the lack of space for a display screen showing more than a couple of lines of text made them difficult to use. The final nails in the coffin were the rapid reductions in the size, weight and cost of desktot, laptop and notebook PCs. Even so, electronic typewriters still had one very convenient feature that laptops lacked, and that was the built-in printer. A few typewriter manufacturers thoughtfully installed printer ports on their machines, which may have prolonged their useful working lives by a few years, but the falling cost of stand-alone printers -- including several with Daisy Wheel mechanisms -- meant that electronic typewriters had mostly disappeared by the mid 1990s.

There is a lively collectors market for antique, vintage and even fairly recently made electric and electronic typewriters. Really old mechanical models from the turn of the last century can change hands for hundreds, and in some cases thousands of pounds. Even machines like the Sharp PA-3100s, which are mere striplings at 40 or so years old, are worth a few quid with runners on ebay selling for between £20 and £50. It’s also worth knowing that ribbon cartridges and spools of correction tape are still available for this particular model, costing around £5.00, which makes it an entirely practical and useable machine. However, electronic typewriters still have a long way to go before they attract the attention of serious collectors and the big money. Current prices are generally quite modest, but that will change. Rare and very early models are almost certain to increase steadily in value so now might be a good time for anyone hoping to get in on the ground floor to do a little homework, keep their eyes open and start stocking up on what could become a worthwhile future investment.

DUSTY DATA

First Seen: 1985?

Original Price: £100?

Value Today: £20 (1021)

Features: 96 character switchable Daisy Wheel, 12 cps print speed, 150 character memory (one line), one touch auto correction, bold, underline text previous text, auto centering, auto return, 10/12/15 em proportional spacing, ribbon cartridge correctable carbon film approx 50k character capacity, 12k character correction ribbon

Power req. 240 volts 50Hz AC

Dimensions: 415 x 363 x 122mm

Weight: 5.5kg

Made (assembled) in: UK

Hen's Teeth (10 rarest) 5

John Adams Intercom Action Lab, 1995

I am an enthusiastic advocate of any toy, kit or assembly set that encourages children to handle small parts, carry out experiments or make and build things.

Generations of kids -- up until the late 1980s, by my reckoning -- have been inspired to follow careers in engineering, science and technology after playing with the likes like Meccano, Lego, chemistry sets, electronic project kits and even Airfix models. Not so much nowadays though. What are generally known as educational toys have become increasingly bland and painfully ‘safe’. In fact a lot of them lot of them are no fun whatsoever, and that element is vital if they are to get school students interested and enthused by science and technology, the so-called STEM (science technology engineering and mathematics) subjects. Heaven knows we need a whole lot more scientists to save us from the future we’ve created. But even a really boring science kit would have been better than the John Adams Intercom Action Lab at encouraging future electronic engineers…

Intercom Action appeared in the mid 1990s and my personal opinion is that any child unfortunate enough to be given one would have been put off learning anything about electronics for life! It actually gets off to quite a good start. The two connector ‘consoles’ onto which the projects are mounted, has to be assembled and it provides a good introduction to the layout and function of various parts, like the connectors, speaker and switch. More good news, the kit contains dozens of real wire-ended electronic components, rather than the encapsulated parts or pre-assembled modules that the few remaining electronic kit-makers started using in the 90s. The basic premise is also sound. It is marketed as a build it yourself 2-station Intercom, but you can tear it down and use the two connector consoles and additional components to make nine other electronic projects, including an LED flasher, timer, alarm, sound switch, humidity indicator, a siren, another alarm and a combined sound generator and lie detector. It sounds like hours of fun, and maybe a good introduction to basic electronics but sad to say, it isn’t.

Firstly the yellow connector blocks on the top of the two consoles are terrible.The block

on the right is one of the better ones. They may have worked, briefly, when it was new, but it seems likely they fail after just a few uses. The contact pins inside the blocks are quite fragile and the continued insertion and removal of component leads and connecting cables causes them to deform. The result is connections become intermittent and it gets increasingly difficult to insert components and cables without bending the thin wires. The more distorted they are the harder it is to get wires into the contact holes, and forcing them causes even more deformation. The second and arguably more serious issue is the almost complete lack of an explanation of how the circuits work. A couple of the project descriptions suggest that changing the value of a component will make the circuit work differently, but that’s it. Having built an LED flasher, for example, and on the offchance the LED actually blinks the user will be no wiser as to how or why. Even basic components like resistors and capacitors remain a mystery but there’s no excuse whatsoever for ignoring the function of the LM324 quad op-amp chip that is the heart of every project. Okay, the lower end of the target audience range is only 10, but what resistors, capacitors and LEDs etc. actually do in an electronic circuit can be simply described. The workings of microchips can be a complex subject, but again, this is a simple and highly versatile IC that can be broadly explained in a few short paragraphs. It might even encourage older children and possibly parents and carers to join in and together delve deeper into the subject. However, that is entirely moot as many projects just won't work and like as not the outfit will be rendered useless by the connector blocks that almost guarantee it will be abandoned after a few outings.

That’s was probably the fate of this one and the reason it wound up on a wonky wallpaper table at a local car boot sale a couple of years ago, priced at only £2.00. It was the box that caught my attention, the cheesy graphics and imagery on the top smacked of the seventies or eighties. Closer inspection suggested it had been little used. It was complete and the consoles had been fully assembled by the previous owner. But it became clear that only a few of the parts had ever been used in anger; components that had were easy to spot as the wires were bent and crinkled and would no longer fit into the connector blocks. The diagrams and brief instructions are very easy to follow. I even managed to get a couple of projects up and running using medical forceps to insert component leads into the connector block’s holes but it was a slow and aggravating process, and certainly not something the average 10-year old would be capable of, let alone older users – like me -- who would very quickly become frustrated by it.

What Happened To It?

John Adams Ltd is a UK based company specialising in science and crafts and arts themed toys and games. The company's current product range appears to have shifted away from electronics to more messy and goop related wares. There’s still a very distinct nod to science and learning and the emphasis is on having fun but at the time of writing – the midst of the Covid pandemic -- their website was in a poor state making it difficult to get more than very narrow overview of what they are up to nowadays.

Back in the 90s, though, the Intercom Lab would have ticked a lot of boxes and must have seemed like a great idea. And it would have been, had the connector blocks had been more robust and the instructions included some easy to follow explanations of what the components do and how the circuits work. If that had happened it may even have rated alongside the all-time classic Philips Electronic Engineer kits that first appeared in the 1960s. I might even have made a small bet that some of today’s scientists and engineers were inspired by it, enough to pursue their current careers. It doesn’t do very well as a collectible either but that has nothing to do with the kit’s contents but it’s age and the fact that it is a bit too recent to warrant vintage status. Give it a few years and with increasing rarity a kit in pristine condition may well be worth more than the couple of quid I paid for this one, but I’m not counting any chickens just yet...

DUSTY DATA

First Seen: 1995

Original Price: £20.00?

Value Today: £5.00 (0821)

Features: Intercom plus 9 other electronic projects, LM324 quad op-amp IC, assorted resistors, capacitors, LEDs and LDR (light dependant resistor), built-in 55mm speaker, connector blocks & on-off slider switch

Power req. 2 x PP3 9 volt batteries

Dimensions: 165 x 100 x 50mm (each console)

Weight: 100g (each console)

Made (assembled) in: England

Hen's Teeth (10 rarest) 7

Heathkit Thermo Spotter MI-104, 1965?

Where would you find a Crappie? How about an Alewife? Obviously the answer is North America, in waters at between 65 to 74 and 48 to 72 degrees Fahrenheit respectively. Yes, of course they’re fish and knowing where they, and many others, are most likely to be lurking is one of the best ways to catch them. So what has this weird-looking object got to do with it? It’s all about fish finding, and the Heathkit Thermo Spotter, Model MI-104 is basically an underwater thermometer. It has three main elements; there’s the hand-held reel with a built-in temperature meter. Wound around the reel there’s a long wire, with a temperature sensor attached to the end. Drop the sensor in the water (attached to a lead weight) and as it descends (or rises) the meter displays the temperature of the water. A chart on the side of the case lists 16 fish species alongside the temperature gradients they are most likely to be found in.

Most of the fish listed are typically found in the US, which is a good clue as to where the Thermo Spotter was made. Or does it? Oddly enough, apart from the fish chart, there is no other clue as to where it came from. There are no markings anywhere on or inside the case. If you want to be really picky this one could have been assembled just about anywhere. The Heathkit name is the giveaway and for over 70 years -- with a couple of interruptions -- they’ve been the world’s leading supplier of home-build electronic kits.

The electronic circuitry inside the Thermo Spotter, such as it is, wouldn’t have taken very long to put together. It comprises the 50uA moving coil meter on the front panel, a small printed circuit board with four fixed resistors and two preset potentiometers (for calibration), a momentary action push-button switch for taking readings, a holder for a single 1.5 volt AA cell and the sensor module on the end of the wire. This almost certainly contains a temperature-sensitive resistor or ‘thermistor’ in a sealed brass capsule. You will have to take that on trust, as opening it up to make sure would be a no-go, as it would almost certainly destroy it

It was a chance catch on ebay whilst trawling (all fish puns intended…) through listings for Heathkit test gear. And as so often happens with oddball items, no one seemed interested in it. The auction was about to end, and never having come across such a thing before, I was curious enough to put in a bold bid of 50 pence over the start price of £10. Luckily it was the only bid, it arrived quickly, and in surprisingly good condition, just needing a wipe over with a soft cloth and a squirt or two of Flash to get it looking like new. There was a long expired AA cell in the battery clip. Thankfully it hadn’t leaked and apart from some gunge on the contacts the Spotter turned out to be a runner. I know that through scientific tests (a kitchen sink and an old school chemical thermometer). After tweaking the twin pots the meter was more or less spot on. There was just one minor cosmetic issue, though, and that was the meter’s transparent cover. At some point the original one had been broken or lost and replaced with one from another, differently shaped meter. It doesn’t look too bad but I would like to find the correct one. However, it’s an old and long-obsolete model and the only one I’ve found on ebay so far cost twice as much as I paid for this Spotter so I’m not holding my breath.

Finding out when it was made or assembled turned out to be surprisingly difficult Several online archives have the odd Heathkit catalogue from the late 60s and early 70s, and some of them include more sophisticated fish finders and related marine kits but alas, no Thermo Spotters. The mid-sixties date is a guesstimate, therefore, based on the overall design, components and materials but as you can see there’s not a lot to go on, so if anyone can help to pin it down, please get in touch.

What Happened To It?

Heathkit started out as the Heath Company in the US in 1947, initially producing kits for home build test equipment and later branching out into home hi-fi, amateur radio, automotive electronics and all sorts of electronic gadgets, even computers. It built up an impressive reputation for the ease of construction, quality and performance of their kits, though they almost always cost significantly more than similar ready-made products.

By the early nineties interest in home build projects had waned and the price differential between kits and off the shelf equivalents widened and in 1992 Heathkit pulled out of the kit market. They didn’t give up, though, and continued making security and lighting products, and in 2011 had another go at making kits. Sadly it didn’t work out and in 2012 Heathkit filed for bankruptcy. New owners took over and the brand was revived in 2013. At the time of writing they were still in business, marketing a small range of retro gadget kits online. There is also a sizeable and enthusiastic fan base with a strong presence on ebay and some eye-catching prices for some of the most popular vintage kits. Alas the Thermo Spotter is not one of them. That is in spite of it being extremely rare (in the UK at least). It is definitely worth about what I paid for it, though, and possibly a little more if I ever manage to find an original meter cover at a sensible price.

DUSTY DATA

First Seen: 1965?

Original Price: £?

Value Today: £10 (0521)

Features: Thermistor temperature sensor, 50uA moving coil meter, meter scale 32 – 86 degrees Fahrenheit (0 – 30 C), push-button reading, cable reel with rewind handle, 10-metre waterproof cable, fish temperature gradient chart

Power req. 1 x 1.5 volt AA cell

Dimensions: 260 x 140 x 68mm

Weight: 500g

Made (assembled) in: USA?

Hen's Teeth (10 rarest) 9

Magna Fumalux FL-400 Lighter & Flashlight 1955?

Yes, it is a cigarette lighter, but a rather unusual one; it almost qualifies as a survival tool… That might not be as far fetched as it sounds. When it was designed, back in the 1950s, at the start of the Cold War, survival was a genuine concern. It ticks a lot of boxes. Fire is a basic necessity in most post apocalypse and prepper scenarios, to keep warm, cook food, and to scare away zombies, wolves and so on. The Fumalux FL-400 uses petrol and, at a pinch, paraffin or diesel oil, all of which should be readily available, compared with new fangled butane gas. Ah, but what about the inevitable lighter flint shortages that follow any worldwide catastrophy, you ask? No problem, the FL-400 is powered by electricity. It has a rather unusual electric ignition system involving a small coil that glows and ignites the fuel-soaked wick. The fact that it is battery powered means there are few moving parts to go wrong and it is very quiet which all add to its charm. One other very handy feature is a built-in flashlight. It’s actually a tiny torch bulb with a lens moulded into the glass envelope, but it is bright enough to do a spot of signalling or read a map

Well done if you spotted the catch in this otherwise flawless argument. The 2-volt battery it uses it is now obsolete, or at least very difficult to get hold of, but there are ways around that, which we’ll come to shortly.

Moving on, it is really easy to use, and being electrically powered, very little physical effort is required to make fire. No clicking or fumbling with flint wheels or stiff buttons, simply slide the switch on the side, this flips open the wick cover/snuffer, moves the ignition coil close to the wick and at the same time powers up the coil and hey presto, you get fire. It’s also pretty much windproof, which is another handy feature in the great outdoors. The flashlight operates using a small button on the side. The case is made of metal, so it’s pretty robust and all of the internal components look like they were made to last. That is in spite of it being designed and built amidst the turmoil and wreckage of post-war Germany. The quality of construction might even be taken as a sign of how quickly that country’s engineering and manufacturing infrastructure would recover and prosper.

The RL-4 battery is one of the most interesting elements of the FL-400. Its small size was a key factor in the design and quite possibly a reason for its very existence.

Essentially it is a miniature lead-acid car battery, but sealed, and it uses a gel, rather than a liquid electrolyte. It was developed in the mid 1930s by a German company called Rulag and although its primarily use was in lighters it also found its way into torches and even powering model aircraft. The RL-4 was actually meant to be disposable. It was cheap and had a life expectancy of 5 to 6 months in a FL-400; however, it could be recharged several times by knowledgeable DIYers and battery sellers with the necessary equipment.

Although the original battery is no longer produced it is possible to cobble together a modern substitute using currently available cells and batteries. Possible candidates include CR type Lithium button cells. These have a 3-volt output; the extra volt is probably not be enough to pop the coil or bulb, but it might be a bit of a gamble, and one I wasn't prepared to take. A safer options is an N-LR1; it’s a 1.5-volt cell used in wireless key fobs and garage door openers. It’s a snug fit but it does the job. Another alternative is a 1.5-volt ‘tablet’ cell extracted from a stack of 6 inside a 9-volt PP3/6F22 type battery, though these won’t last very long.

The simplest but least elegant way of installing a cell or battery in the case is to solder a pair of wires between it and the lighter's contacts. A much neater approach is to make a battery holder or adaptor, the same shape and layout as the original. This isn’t too difficult and avoids damaging the lighter. There are many ways to make one but since I acquired a 3D printer a year or so ago -- and got instantly hooked on it’s possibilities -- this had to be the only way to go. It’s a simple enough shape, a small rectangular box with cut-outs for the chosen battery and channels for a pair of thin brass contact strips. It only took an hour to design a couple of them (centre and right in the photo above) using the excellent (free and very easy to use) Tinkercad online 3D CAD application (www.tinkercad.com/). The resulting .obj file was ‘sliced’ (prepared for printing) using a program called Cura (usually supplied with a 3D printer), and printed on an Ender 4 using PLA filament. This took just under an hour; fine tuning the printer settings could easy cut that down to 20 - 30 minutes or less. (Sorry for all the 3D jargon but trust, me it is addictive, a lot easier than it sounds, loads of fun and nowhere near as expensive as you might think).

If you are interested in collecting vintage cigarette lighters then one of the best places to start, and where this one came from, is ebay. At the time of writing there’s usually a dozen or more FL-400s selling for between £5 and £50. I struck lucky with this one and snagged it for the opening bid price of a fiver, possibly because Fumalux had been misspelt. It was as described, in near mint condition, with an original battery, which, (needless to say, was as dead as a doornail. All it needed was some light cleaning and light oiling, a quick test of the electrics, a tank full of lighter fuel and my repro battery. After a few attempts it fired up – quite literally.

What happened to it?

The origins of the FL-400 date back to the late 1930s when a German company, Pyrolex, developed an electric lighter that used a torch-bulb element to ignite the wick. The company and its patents were purchased by the Domo Company (named after its founder Doctor Mohr) in 1938, but production was halted following the outbreak of WW II. It resumed in 1946 after securing supplies of the fine tungsten wire needed to make the ignition coils. The same year they introduced the FL-2 the first model with a built-in flashlight. This was the forerunner of the FL-400, which appeared a few years later and continued in production, more or less unchanged for another 50 years, with lots of special editions and rarities for collectors to look out for.

Collecting vintage cigarette lighters has always been popular, and for good reason. They’re small and easy to find. There are plenty to choose from, hugely varied in design and range in price from next to nothing, to eye-wateringly expensive. They also overlap with many other areas of interest from precious metals and jewellery, to engineering, technology and history. There’s something for everyone but as usual it’s a bit of a minefield, especially if you think it's a way to make money. If you are starting out I suggest that you keep it cheap and simple while you learn the ropes. It’s a good idea to specialise and vintage electric and electronic lighters is as good a theme as any, and currently there are still plenty of bargains to be had. And don’t forget to keep one primed and handy for disasters. You never know what’s around the corner…

DATA

First Seen: 1955

Original Price: £5.00 ($9.95)

Value Today: £20.00 (0920)

Features: Petrol lighter with battery-powered incandescent coil ignition, built-in flashlight (3-volt lens-cap bulb), steel case

Power req. RL4/L450/RZP2, gas-tight 2-volt lead acid gel battery

Dimensions: 56 x 52 x 14mm

Weight: 61g

Made (assembled) in: Germany

Hen's Teeth (10 rarest): 5

Sawyer’s View-Master Stereoscope Model C, 1950?

The featured item in this episode of dustygizmos doesn’t have any electronic circuitry so there’s no need for batteries or mains adaptors, but it is solar powered, sort of… It’s a View-Master Stereoscope, in particular a late model C and back in the 1950s and 60s almost every family had one. Not only that, no matter where you went in the world you could buy stereo viewer discs from shops and kiosks, usually featuring the attraction that you had or were about to visit. It’s a design classic and almost certainly holds some sort of record for being one of the longest-surviving media formats. The discs it uses have remained largely unchanged and backwards and forwards compatible since the View-Master was introduced in 1939, to the present day.

Photos were taken using either a specialist stereo still camera or more often than not, two ordinary still cameras mounted a head’s width apart on a special tripod mount. This replicates the stereoscopic effect of our own vision, with two images taken at slightly different angles, Viewed together they give the impression of three-dimensions and depth. Seven pairs of colour transparency images – similar to photographic slides, but much smaller -- measuring approximately 12 x 10mm, are mounted on a 9cm stiff paper or (later) plastic disc, opposite one another. To view images a disc is slotted into the top of viewer, the user then looks through it, like a pair of binoculars, whilst pointing it at the sun or a bright light to illuminate the images. A lever mounted on the side of the viewer rotates the disc, one scene at a time.

The stereoscopic effect can be quite dramatic and the photographers who took them became adept at enhancing the sense of depth by making sure that the scene was brightly lit and included plenty of people and objects at various distances from the lenses.

Early View-Master viewers were sturdily built with ground glass lenses and a robust advance mechanism that rarely, if ever broke down. The manufacturer was confident enough to rivet the cases closed, so apologies for no interior shots; they’re not worth a great deal but I have no desire to break one apart. The viewer shown is one of two Model Cs in my possession, inherited from family members over the years. As far as I’m aware both were originally purchased in the early 50s. One of them came with an apparently quite rare bronze-effect plastic storage case for a viewer and around 50 discs. Most of these date from the 50s and early sixties and include such diverse subjects as the Coronation of Queen Elizabeth II in 1953, Tulip Time in Holland, The Picturesque People of Brittany and scenes from the 1950 Miss America Beauty Pageant, held in Atlantic City. Both viewers are in excellent condition and apart from an occasional wipe over with a duster, they look and feel like new and likely to still be working in another 60 or 70 years. The images on the discs show no sign of fading either and the colours are as bright and vibrant as the day the photos were taken.

What Happened To It?

The View-Master has a long and eventful history but the milestones were the coming together, in 1938, of Edwin Mayer who founded Sawyers Photo Finishing Service in 1919, and William Gruber, a German organ maker. Both had an interest in different elements of stereo photography and disc manufacture and between them they came up with the View-Master name and concept. The first pre-production models were shown at the 1939 New York World’s Fair and it was a success from the start. However, in the early 1940s the biggest customer was the US military who ordered 100,000 units and more than six million discs for training purposes.

One of Sawyer’s View-Master’s most successful ventures was to buy out rival stereoscope manufacturer Tru-Vue, in 1951. In doing so they also acquired the licensing rights to Disney and later Hanna-Barbera’s vast image libraries. Sawyer developed a personal stereo camera in 1952, so users could create their own discs. This also proved popular but it went out of after 10 years and is now highly sought after. Model upgrades followed, including ones with built-in battery powered light sources, lightweight plastics replaced Bakelite and there was even a disc projector.

Following a takeover of Sawyer by General Aniline and Film in 1966 there was a noticeable increase in special edition versions and tie-ins with popular TV series, movies and cartoons, like The Man from U.N.C.L.E. The Beverley Hill Billies, Time Tunnel, Star Trek and even our own home grown Doctor Who. In the 70s the View-Master gained an audio facility with ‘talking discs’. The company changed hands yet again in 1981 and was renamed VMI (View-Master International), and again in 1989, ending up as part of Tyco Toys. VMI was included in another merger, this time with Mattel, in 1997 and marketed under the Fisher Price brand. In 2015 Mattel got together with Google to develop the View-Master Virtual Reality Viewer, using a smartphone to display 3D images. Optical viewers are still being made, though and there have been 25 different models to date and with more 1.5 billion discs produced it is safe to say they are not exactly rare.

Viewers like the Model C can be found in abundance on ebay for as little as £10 and there’s no shortage of discs, from all eras of the product’s history. There are plenty of rarer View-Master viewers, though. For example, brown Bakelite Model C’s and ones with a border around the Patent information are worth significantly more. Discs produced for training and promotion and accessories can also fetch a very pretty penny. If you want to get involved there’s a lively collector’s market, but plenty of pitfalls to avoid so do some homework before diving in.

DATA

First Seen: 1946

Original Price: $2.00 (around £5.00)

Value Today: £20.00 (0820)

Features: Stereo viewer, 7 image disc, manual frame advance, natural light illumination (battery powered light optional), fixed focus optics, Bakelite body

Power req. n/a

Dimensions: 111 x 75 x 95mm

Weight: 185g

Made (assembled) in: Portland USA

Hen's Teeth (10 rarest): 4

Eddyprobe II ECT Material Integrity Monitor, 1975?

There are a number of unfamiliar initialisms* in this episode of dustygizmos and I freely admit to having to look them up, often without becoming very much wiser. So we’ll kick off with a couple of the key ones relating to this Eddyprobe II Material Integrity Monitor featured here.

The first is ECT or Eddy Current Tester; it’s one of several techniques used in science and industry to inspect for flaws or measure the characteristics of conductive materials – more about that in a moment. The next one is NDT or Non-Destructive Testing. This one is self-explanatory and in other words, means a method of testing materials without damaging or destroying them, which is a good thing when you want to make use of whatever it is you are testing…

Back to ECT and it’s a fairly old idea. Much of the credit for it belongs to Michael Faraday and his experiments in electromagnetism the 1830s. ECT is based on the fact that electromagnetic fields change when brought close to metallic objects. It’s a bit like the way metal detectors work, but with a great deal more precision, and in this instance the detector head or probe is usually in direct contact with the object or material concerned.

In the absence of any sort of hard facts or a user manual, it seems highly likely that the Eddyprobe II is designed to use a range of probes that can check the thickness of materials and search for flaws in welds and coatings and so on. The probe that came with it almost certainly houses a small coil (according to my test meter it has a resistance of 1.5 ohms). Inside the case, in addition to the front panel meter (scaled ‘% Calibrated Depth’) and controls, there are two circuit boards; one is marked ‘Detection’ the other ‘Alarm’. The detection board appears to be an oscillator whilst the alarm board has four op-amp chips (741s). These would be used to analyse the signal coming from the probe, generate a reading for the front panel meter and set a level or threshold that illuminates a small lamp when a particular value has been exceeded. This is all guesswork please so feel free put me right or fill in the gaps.

The controls on the front panel comprise a rotary switch, to turn it on, select power supply option (external DC or internal batteries – four 9 volt PP6 types), and the operating mode. Two potentiometers are used to set zero on the meter and adjust sensitivity, and on the far right there’s a variable capacitor labelled ‘Lift Off’. The purpose of most of them is fairly clear but Lift Off remains a bit of a mystery. The probe connects to the main unit using a mini BNC socket and on the underside of the sturdy metal case there’s a socket and switch for an external DC supply and a folding bench stand.

It is impressively well made. The circuit boards are hand assembled and the internal wiring looms are impeccable, neatly tied and as good as anything you’ll see on a high quality vintage precision instrument. That is exactly what it is and it is clear from the number of preset controls and test points on the two boards, which suggest that it requires a fair amount setting up and calibration before it can be used in anger.

I came across this Eddyprobe II at a South London car boot sale a couple of years ago. It was in its original box with a shipping label dated June 1980 and that, and the electronic components it uses is responsible for the guessimated manufacturing date of 1975. It was in apparently as-new condition. The stallholder said that a few people had taken it out and had a look at it but they, like him (and me), had no real idea of what it was for. The front panel meter drew me to it. It’s a distinctive high-quality type made by Sifam and appeared to be identical to the ones used in Mini Instruments Geiger Counters. I just happened to have one at that time that was in need of a replacement. The one on the Eddyprobe appeared to be in excellent condition with the needle moving freely, though the only real way to test it would be to remove it from the case. These meters can be hard to come by and cost upwards of £20 second-hand and even though it would be a bit of a gamble anything less than that would make it a worthwhile purchase. I was particularly pleased therefore when the stallholder offered it to me for a fiver!

The instrument was in outstanding condition and looked as though it had rarely, if ever been used but unfortunately it came without a user manual or any documentation. Before I scavenged it for parts I thought it right and proper to find out a little more about it. Sadly there was almost nothing about it on the web, apart from a few references to the manufacturer Inspection Instruments (NDT) London. Most of what I was able to glean was based on the few tidbits picked up from the Internet and by powering it up to see what it does. After a fair amount of fiddling I reckon I managed to figure out the rudiments – with apologies to seasoned ECT and NDT specialists. My rudimentary test consisted of a thin strip of steel sprayed with several layers of paint of varying thickness and placed on small groups of nuts and washers,

Following a lot of trial and error the set up procedure seems to involve placing the probe on the surface of the material to be checked and zeroing the meter (it is incredibly sensitive), then, slowly moving the probe over the surface of the material whilst observing the movement of the meter. There was a definite twitch either side of zero at the points where the paint layers varied, and much larger deflections as it passed over the areas where the nuts and washers were placed. Admittedly it was a far from scientific test but at the very least it suggested that it is working and gave a hint at how useful it would be in the hands of a experienced and knowledgeable operator. For the record although the meter was in tip-top condition the unusual offset-centre zero configuration made it unsuitable for easy transplantation into a Geiger Counter.

What Happened To It?

ECT is still widely used for NDT but modern instruments are vastly more accurate and sophisticated thanks to computerisation and a lot of digital jiggery-pokery. There is now a vast array of increasingly specialised methods of NDT involving acoustics, X-Rays, lasers, magnetic flux, magnetic particles, microwaves, neutrons, thermal and infrared, to name just a few.

In it's day the Eddyprobe II was probably one of the go-to pieces of kit for a wide range of NDT applications but it doesn’t seem to have done Inspection Instruments Ltd. of 32 Duncan Terrace London much good. I found only a few brief references to the company on the web, nothing about their history or any other products. What little there is tapers off in the mid 1980s suggesting they were either taken over or they went out of business.

When new it must have cost several hundred pounds, possibly a great deal more with a full set of probes. Today, and in spite of it apparently being in good working order, it's value lies mosly in the worth of the parts it contains and the £5.00 I paid for it is probably only a little less than it would fetch on ebay. I cannot see collectors of vintage scientific instruments getting overly excited by it, even though it is, apparently, quite rare, but as with most of the other exotic, unusual and plain weird scientific and industrial artefacts featured in dustygizmos, this may end up being its one and only appearance on the web, which, hopefully, someone somewhere may find useful or interesting.

*Apologies for being a bit nerdy. Initialisms, as opposed to acronyms -- e.g. NASA etc.-- are the ones you can make words out of…

DUSTY DATA

First Seen: 1975?

Original Price: £?

Value Today: £10.00? (0320)

Features: Eddy Current Tester (ECT), interchangeable probe, '% calibrated depth' scaled meter, variable sensitivity and Lift Off controls, alarm indicator, carry handle, folding bench stand

Power req: 4 x PP6 9 volt battery & external DC adaptor

Dimensions: 206 x 140 x 160mm

Weight: 2.2 kg

Made (assembled) in: England

Hen's Teeth (10 rarest): 9

Minidyne Mk II TENS Machine, 1970

Most of us wisely avoid getting electric shocks but for some it has proven to be an effective method of pain relief. It’s not a new idea; eminent Roman doctor Scribonius Largus (63AD) claimed that standing on an ‘electric fish’ could be helpful for relieving aches and pains. Over the last few centuries numerous electrically based therapies have been promoted as cure-alls for all kinds of maladies but it wasn’t until the latter years of the twentieth century that the use of mild electric shocks for controlling pain was taken seriously by medical science.

It’s known as Transcutaneous Electrical Nerve Stimulation or TENS and the first commercially available TENS ‘machines’ appeared in the early 1970s. It could mean that this British made Minidyne Mark II is one of the very first of those devices; a date sticker inside the case backs up this premise. It was made by Electro Medical Supplies, (now EMS Physio) based in Wantage, who are still in the business of making and supplying TENS machines, amongst a great many other medically related things. But back to the Minidyne Mk II, what it does and how it does it.

As you can see the front panel is fairly sparse. From left to right there’s a pair of screw terminals, for the leads connecting the unit to two conductive skin pads. It is likely that when this first appeared they would have been metal discs, probably held in place by sticking plaster. The pads used by modern TENS devices are usually made of fabric or rubber coated with a very sticky conductive gel. The knob next to the terminals, marked ‘Output’ is for controlling the intensity of the shock, from 0 to around 200 volts. The other knob, labelled ‘Off’ and ‘Surge’ is for switching the unit on and adjusting the pulse repetition rate, between on and off once a second to 5 seconds on and 5 seconds off. A neon indicator mounted just above the Output terminals glows with each pulse and this is accompanied by a fairly loud buzz. This may be unintentional and is almost certainly coming from the laminations of a small transformer inside the case.

The early seventies as the likely date of manufacture is confirmed by components on the circuit board. This is actually a piece of ‘Veroboard’, a perforated ‘matrix’ board with strips of conductive copper tracks on one side and still widely used for prototyping and short production runs. Mounted on the board there’s a good assortment of 1970s electronic components, including three OC45 and two OC72 germanium transistors in common circuit configurations. The first section is a bistable multivibrator, which generates a variable square wave pulse, controlled by the Surge knob. The second part of the circuit is responsible for the high voltage output going to the skin pads. Pulses from the multivibrator trigger an oscillator circuit, via an OC35 power transistor, that drives the previously mentioned transformer. This steps up the voltage, which goes to the front panel’s Output terminals. Build quality is typical for a high-end and what was probably an expensive medical instrument. It is housed in a sturdy metal case and fully self-contained with power coming from a pair of 9 volt PP9 batteries that fit snugly into a compartment in the rear of the case.

Small grey boxes with a couple of grey knobs rarely attract more than a second glance but it had been a miserable, wet day at the antiques fair in Surrey where I found this instrument. Only a few stallholders had braved the weather and this was about the only thing that caught my eye. It was only when I picked it up that I realised it wasn’t some sort of power supply or switch box, and the knobs labelled Surge and Output suggested it was worth closer inspection. The stallholder confirmed my suspicions that it was probably a TENS machine. A few years ago I bought one in desperation from Boots the chemist. I had been suffering from a painful frozen shoulder for several months and pills and potions were no longer working. For the record it really helped! Anyway, the asking price of £10 for the Minidyne was swiftly reduced to a fiver; I doubt many visitors had shown interest in it. This was a fair price as it was really clean, inside and out. It looked like it had been little used and I could see potentially useful vintage components on the circuit board when the battery cover was removed.

It powered up first time and the neon lamp blinked on and off so it looked like there was a good chance it was working. Hooked up to an oscilloscope I confirmed the output voltage and current wasn’t high enough to be especially dangerous but in the end there’s was only one way to test something like this… Yes, it works but the shocks it delivered were unlike the modern TENS machines I have tried. The oscillator is running fairly slowly producing a relative sharp, rasping sensation. It can get uncomfortable at the higher levels but at lower settings it would be quite distracting, more than enough to take your mind off a nagging pain, which I found to be one of the ways these things work. Important safety tip. There’s no way I would have tried this device on myself had I not thoroughly checked it first; more importantly I have a blanket ban on hooking myself up to anything that is mains powered! Nevertheless, it always pays to be careful. Battery powered devices can deliver nasty and potentially harmful shocks – ask anyone who has been Tasered…

What Happened To It?

This is not dustygizmo’s first encounter with a company called EMS (see Stammering Oscillator) and although the makers of this device previously denied they made it, there are a great many similarities between the two items. EMS can’t disown this one, though. Apart from anything else the maker’s label on the back panel clearly states that it was made in Wantage -- they’re still there -- and still in the medical equipment business. Charles Greenham founded the company in 1924. He set up shop in central London selling sunlamps and batteries. It appears to have been quite successful from the get-go and expanded rapidly, moving to larger premises in Great Portland street in 1933. EMS continued to prosper, growing and diversifying into other areas of electrotherapy and at the same time creating a significant export market for their products. The company eventually outgrew its London premises and moved to Wantage in 1968. Currently it employs more than 100 people and continues to innovate, develop and supply medical equipment and scientific instruments.

Vintage medical apparatus has always been popular with collectors but they tend to favour older items made up until the early twentieth century. Quack electrical devices are also in demand but for the moment at least there appears to be little appetite for more recent products from the 70s and 80s. I doubt that anyone would pay more than £10 for one of these, not that they turn up very often. In fact this particular model appears to have no web presence whatsoever. This might suggest that few were made; it may even be a pre-production prototype given that it doesn’t have a purpose made printed circuit board and a sticker with the number 40 on it. Either way this doesn’t make valuable, now or in the foreseeable but its apparent rarity and the part it played in the very early days TENS technology deserves recognition and its appearance on these pages.

DUSTY DATA

First Seen: 1970

Original Price: £?

Value Today: £10 (0320)

Features: Single channel TENS machine, variable output (0 – 200 volts), variable ‘Surge’ (pulse rate), neon pulse indicator, screw terminals, carry handle

Power req: 2 x 9 volt PP9 battery

Dimensions: 200 x 158 x 130mm

Weight: 1.1kg

Made (assembled) in: England

Hen's Teeth (10 rarest): 9

Sanyo Memo-Scriber TRC-7040A 1981?

The word ‘dictation’ has all sorts of connotations in today’s hypersensitive offices and workplaces. But not so long ago it simply meant turning the wise and often banal utterances of mostly male middle management and senior company bosses into coherent words on paper or email messages by mostly female secretaries. For the past 100 or so years the process of dictation was been made more efficient by the invention of voice recording devices, more specifically dictating machines. Over time they evolved from cumbersome mechanical contraptions to pocket sized memo recorders and more recently, digital devices and indeed, any smartphone equipped with a voice-recording app.

The development of magnetic tape recording in the 1950s had a huge impact on the market. It made dictating machines easier to use, an important consideration for dim-witted company executives, who could just about be taught how to use them for themselves. It also brought the price down, to the point where they became a standard piece of office equipment. Later on in the fifties the technology took another big leap forward with the introduction of a score or more ‘idiot-proof’ tape cartridge and cassette designs. In the normal course of events the competing formats would have fought it out for a year or two until one system prevailed. For some reason this never quite happened with dictating machines. As late as the late 90s, when tape-based dictating machines were in steep decline at least four cassette/cartridge formats were still in production. The Sanyo Memo-Scriber featured here uses one of them, the Mini Cassette, developed by Philips in 1967, just 4 years after the launch of the original Compact Cassette.

Mini Cassettes look remarkably similar to Microcassettes (introduced by Olympus in 1969). Although they are similar in size and appearance the key differences lie in the tape deck mechanisms. Microcassette machines use a miniature capstan drive system, like most large reel-to-reel machines and Compact Cassette recorders. In contrast Mini Cassette recorders the tape is drawn past the heads by the spools. This wasn’t a cost-cutting measure but a purely practical measure as it meant the tape could be rapidly rewound if, for instance, the person transcribing the tape missed or misunderstood a word or phrase. Near instant rewind is difficult to achieve on a capstan drive deck as during playback the tape is tightly sandwiched between a motorised spindle and a rubber capstan. It can be done but it requires a significantly more complex and therefore costly drive mechanism.

The fast rewind function is called Backspacing and it is one of the main features on the Sanyo Memo-Scriber. A slider control on the front panel varies the amount of time the recording is rewound between 0 and 10 seconds. There are several other notable features, including the lack of any recording facility. This might sound a bit odd but the simple fact is the Memo-Scribers’ only job is to replay tapes. There’s also a need to erase recordings after they have been transcribed, both for security reasons and to return the tape to stock for re-use. Tapes con this machine can be erased in real time or rapidly, using a Quick Erase function. There’s a foot pedal control, so the operator can pause or Backspace the tape without having to remove their hands from the keyboard. A three-digit tape counter is mounted on the left side of the case, making it easier to find specific parts of a recording. It has a headphone socket so recordings can be replayed in privacy or in a noisy environment, (otherwise it is heard through the built-in speaker). The transport keys are ‘soft-touch’ microprocessor controlled, which simplifies operation and further reduces the number of moving parts in the deck mechanism. Finally, it runs on a 9 volt DC supply provided by an external mains adaptor that connects to a socket on the back of the unit.

This Memo-Scriber was a chance find during one of my occasional ebay trawls for tiny tape recorders. Nowadays it mostly turns up pocket Micro-Cassette memo recorders, which are still a few years away from being rare, or interesting. This one caught my eye, though, mainly because of the low asking price, (£8.00), apparent good condition, unusually specific set of functions, and the cosmetic design, which mimics larger tape-top Compact Cassette recorders of the same age, but in miniature. It turned out to be as good as it looked and in full working order. All it needed to make it presentable was some light dusting and polishing. The Backspace function is still very light on its feet and sound quality is pretty good.

What Happened To It?

Voice recorders have now moved firmly into the digital realm since the first models appeared in the mid 90s and devices that can translate speech directly into text are at or close to being a viable alternative to human transcription. Machines using Mini and Micro Cassette formats are almost certainly technically obsolete, as it doesn’t appear that any are being manufactured. If so production probably stopped only comparatively recently as there are still plenty of quite new looking models on sale in shops, on ebay and at car boot sales. ‘New’ blank cassettes are also widely available, though the ones I’ve seen seem a lot more expensive than they used to be, which suggests that supplies are gradually drying up. Collectors of vintage dictating machines and recorders do exist, though they tend to focus on the very early ‘phonograph’ types using wax discs and cylinders that first appeared in the 1920s. Notable milestone models can also fetch fancy prices, though I suspect the hard-core collector’s interest tails off on anything made after the mid sixties.

Tape-based dictating machines, especially if they use one of the failed first generation cartridge or cassette formats can tickle the fancies of collectors of vintage audio equipment but the bottom line is there are no reliable guidelines as to what machines like this Sanyo Memo-Scriber are worth now, or in the foreseeable future. At the time of writing prices are all over the place so if you are interested in starting a collection with an eye on increasing value you can afford to be picky and focus on sensibly priced, good quality working machines from well known manufacturers, preferably with their original packaging and instructions.

DUSTY DATA

First Seen: 1981?

Original Price: £100?

Value Today: £10 (0320)

Features: Mini Cassette format, 30 minutes recording time per side, microprocessor controlled soft-touch transport keys, quick erase facility, variable backspace (0 – 10 seconds), 3-digit tape counter, foot control, headphone socket (3.5mm minijack)

Power req: 9 volts DC (external mains adaptor)

Dimensions: 237 x 185 x 54mm

Weight: 1.1kg

Made (assembled) in: Japan

Hen's Teeth (10 rarest): 6

Playcraft Bandbox Talent Show Microphone, 1963

There’s more to this Playcraft Bandbox Talent Show Microphone than it appears. Much more, in fact most of it is missing. It’s actually an accessory, sold separately to the main component, which is the Bandbox MW/LW Transistor Radio also from toy maker Playcraft. Sadly the evidence is few of these radios were made, or survived. I’ve been on the lookout for one for several years, but so far so luck. So rather than leave the microphone gathering dust it’s time for it to make its debut on dustygizmos. Rest assured if and when I ever manage to get my hands on a Bandbox Radio they will be reunited here

Although it still functions perfectly well as a microphone in its own right it was originally designed to be used with the Bandbox radio, dating from 1963, or thereabouts. The name and illustrations on the box clearly suggests that fame and celebrity was as much of a draw to kids back in the sixties, as they are today. Plugging the mike into the radio turns it into a pint-sized PA system so aspiring songsters could sing along to their favourite tunes. Fortunately it wouldn’t have been very loud, as the radio would have had an audio output of only a few hundred milliwatts.

The actual microphone is contained in a small metal capsule mounted in the cream coloured section on the top of the ‘stick’. It’s a dynamic type, nothing fancy but being a toy it would have been good enough for youthful warblings. It connects to the radio with a generous 5 metres of cable, terminated in a mono 3.5mm jack plug. It looks the part too and the styling was clearly inspired by the hand held mikes of the day.

I’ve had this one in my to-do box for several years, waiting for the day when it could be plugged into the companion radio. As I recall it came from an odds-and-ends box under a trestle table at a large antiques fair in the Midlands. However, although this was a good few years ago I remember buying it mainly because of the typically sixties artwork on the box, which screamed vintage technology, the microphone inside, which appeared to be complete and in good condition, and crucially the asking price of just 50 pence. At that point I wasn’t too concerned if it worked or not, and once I figured out that it just an accessory it was put to one side to await the arrival of the radio. I didn’t check to see if worked until recently when I plugged it into a sixties tape recorder. Microphones tend to be fairly robust if looked after so it wasn’t too surprising to find out that this one was still okay, not great, in terms of sound quality but that was to be expected.

What Happened To It?

The Playcraft brand dates back to 1949. It was created as a subsidiary of Mettoy, founded in the 1930s by established German toy makers Arthur Katz and Philipp Ullmannas. Both were Jewish and with help from Lord Marks (of Marks & Spencer) they moved to the UK just before the outbreak of the Second World War. Mettoy (the name comes from metal toy) became one of the best-known manufacturers of metal toys, including the iconic Corgi model range. Playcraft’s brief was to develop new products, market craft kits, moulded plastic toys and later model railway sets. The foray into radios and the Bandbox range appears to have been fairly short-lived. It hasn’t been mentioned in any of the company profiles I have seen so information is somewhat limited. This is a little surprising as during 50s and 60s Mettoy and Playcraft went through a period of rapid expansion. It became very successful and profitable, much written about and won a raft of industry awards. It didn’t last though; things began to go wrong in the early 70s. Following almost a decade of losses the company went into liquidation in 1983 with some the most popular products and brands being sold off to management buyouts and rivals.

My brief research into the story behind the Talent Show Microphone has proved almost entirely fruitless, so far. As usual contributions and corrections are welcome. I could find no references to it on the web, no other examples have shown up on ebay recently and it is quite possible that this will become the first and only one featured in Google Images. It seems to safe to say, therefore, that it is somewhat rare but on its own it is merely a curiosity and probably not worth more than five to ten pounds. Teamed up with a Bandbox Radio it becomes a much more interesting prospect. However, even if that is also in good condition and in working order, preferably with its original box, they may not be worth a great deal more. Hopefully, though this won’t be the end of the story.

DUSTY DATA

First Seen: 1963

Original Price: 25 shillings (£1.10)

Value Today: £10 (0220)

Features: Hand held mono dynamic microphone. 3.5mm minijack connector, 5 metre connecting cable

Power req: n/a

Dimensions: 190 x 48mm

Weight: 65g (ex cable)

Made (assembled) in: Great Britain

Hen's Teeth (10 rarest): 9

Microflame Model B Gas Welding Torch, 1970?

Here’s one for Star Wars trivia fans; what is the connection between R2D2 and 3-CPO and laughing gas? Several, probably, but the one we’re interested in concerns the Microflame Model B gas blowtorch. Okay, that needs some explanation

The Microflame was a versatile and weirdly common piece of kit in that far, far away galaxy, making several cameo appearances in Star Wars Episode IV - A New Hope, released in 1977.

The first time we see it is in the hands of a Jawa, welding a Restraining Bolt onto R2D2. Luke Skywalker later uses his Microflame to repair 3-CPO’s arm, and for some reason Han Solo has one the gas cylinders attached to his belt. But what about laughing gas? Well, the Microflame has two gas cylinders. One contains Butane, which makes the flame, the other one is filled with ‘Micronox’, Microflame’s trade name for Nitrous Oxide. This is a powerful oxidizer, with similar characteristics to Oxygen, making the flame even hotter. Nitrous Oxide or laughing gas is best known as an anaesthetic. It’s also used in whipped cream makers, making souped up cars go faster and recently it achieved notoriety as a popular recreational drug, which the tabloid press like to call ‘Hippy Crack’.

When not being used to repair Sci-Fi robots the Microflame’s main claim to fame is the impressive 2800⁰ Centigrade flame it produces at the end of the swivelling ‘wand’. That’s pretty damn hot, though the use of the word ‘welding’ in the name is a tad optimistic. It’s certainly hot enough to melt brass and copper for brazing small metal parts, but it would struggle with steel, and the flame simply isn’t large enough, and the cylinders don’t hold enough gas, to heat up large or thick pieces of metal. But that wasn’t what it was meant for; it’s a compact pocket-size blow torch for making or repairing small things, like models, ornaments, repairing metal objects and so on. Back in the 1960s, when Microflame first appeared model making, home crafts and DIY were hugely popular and big business, especially in the US.

The design is elegantly simple. The two cylinders are mounted in a sturdy cast metal frame that acts as a handle. They are kept in place by cup-shaped holders attached to a screw thread and a thumbwheel. Rotating the thumbwheel pushes the cylinder up and into the valve block where a thin metal tube punctures the seal in the neck of the cylinder, releasing the gas. The red and green knobs control gas flow to the burner head at the end of the wand, which can be fitted with a variety of attachments, for soldering or making larger or smaller flames. In the US a small cottage industry grew up around the Microflame with third party accessories and numerous books and magazine articles showing how to use it and construction projects.

Microflame caught my eye back in the late 1960s, appearing in ads in publications like the wonderful and much-missed Exchange & Mart. At the time I was briefly interested in radio controlled model aircraft and for some reason it seemed like something I might need (though flames and fabric-covered balsa wood would not have been a happy combination…). It never happened; they were prohibitively expensive at around £25, and my spectacularly unsuccessful attempts to build and fly model aircraft dissuaded me from spending any more on that doomed hobby. I had forgotten all about the Microflame until I came across this one at a car boot sale a few years ago. This time I could afford the £1.00 asking price for what appeared to be an almost complete kit in apparently very good condition in its original, though very tatty cardboard box. Not that I had any particular use for it but it rekindled the urge to own one, and as I reasoned, who knows, it might come in handy one day…

It came with a couple of unused cylinders and after applying some silicon spray to the rubber washers and gaskets to soften them up, decided to give it a go. It worked really well, but not for long. The Butane gas cylinder lasted about 10 minutes, which was probably due to leaky seals. Supposedly they’re good for around 30 minutes burn time, but even that wouldn’t be much, even for model engineering applications. It wouldn’t have been a huge problem back in the day. According to the price label on the box that came with the kit replacement cylinders cost 75 pence for two. That would have made it reasonably affordable to use but the problem now is Microflame disappeared in the late 90s, along with a reliable supply of cylinders. Articles on the web suggest that a UK company may still have stocks, or the facility to refill them, but at a cost. There are alternatives, however. Nitrous Oxide cylinders for making whipped cream (and brief ‘highs’) are readily available, and a couple of websites suggest that the butane cylinder can be back-filled using a cigarette lighter refill, either directly through the burner wand, or by drilling the cylinder and fitting the refill valve from a discarded lighter. Both methods appear quite risky so I won’t be trying them anytime soon.

What Happened To It?

Production of the Microflame began in 1966. It was the brainchild of Leonard E. Laske from Minneapolis, where he established a factory to make them. Little has been written of its history except that at some point, probably in the early to mid 1990s, it looks like the company was bought out by Radio Shack who marketed it under their Archer brand name. Radio Shack collapsed in 2007, though the re-branded Microflame disappeared from their catalogues in 2001.

Microflame may be no more but butane gas powered blowtorches live on, both as DIY and kitchen tools. Some of them are even smaller than the Microflame but as far as I am aware it still holds the record for temperature, thanks to the extra firepower from the nitrous oxide cylinder. Temperatures of 3000 degrees and above are still achievable but only from much larger, professional and industrial dual-cylinder outfits, none of which fit easily into the hand, or pocket. Original vintage Microflame kits appear to quite collectable, if ebay prices and the healthy demand in the US are anything to go by. Sales regularly achieve between £50 and £150, depending on the type, age and condition. They appear only occasionally on ebay UK and the two fairly rough looking examples I followed sold for only £10.00 and £18.00. It is notable that the US offerings with the highest prices prominently mention the Star Wars connection so there may well be a few fast bucks to be made if you can find one cheap enough at your local boot sale or antique market.

DUSTY DATA

First Seen: 1966

Original Price: £25.00

Value Today: £30 (0220)

Features: Micronox (Nitrous Oxide) & Butane gas welding torch, 2800⁰C flame temperature, rotating flame ‘wand’ interchangeable nozzles, soldering iron attachment

Power req: n/a

Dimensions: 138 x 50 x 30mm

Weight: 336g

Made (assembled) in: USA

Hen's Teeth (10 rarest): 7

Intel Play QXP Computer Microscope, 1999

There seems to be no hard statistics concerning the idea that young children, actively encouraged to play with‘scientific or mechanical toys, are more likely to pursue further education and lucrative careers in technology, science and engineering. Previous generations had far fewer distractions and countless lives were almost certainly shaped by early and prolonged interactions with the likes of Meccano, proper smelly and incendiary chemistry sets, electronic building kits even train sets. Of course educational toys are still with us but they tend to be worthy, sanitised, and rigorously safety tested. This leaves little opportunity to experiment and learn, or they’ve been completely detached from the real world and available only as virtual simulations. In other words all of the adventure, invention and even danger has been removed, along with much hope of them being fun or engaging to play with.

It has been a relatively slow process, though, and not all kids tech is necessarily bad, and for a short while the mighty Intel Corporation had a hand in a range of toys that were supposed to combine fun and learning in a way that may well have led a few youngsters into a life of science. The headline product was the Intel Play QX3 Computer Microscope, further explanation of what it is seems unnecessary, but the key feature was that it was very simple to use, and in spite of it being a toy, it was actually quite a capable instrument and teaching tool.

It’s a kid-friendly eyeful; big and tactile with its, then, trendy see-though blue plastic housing (remember the iMac G3?). The large knobs on the right and left sides are for focussing – they raise and lower the specimen platform – and the big green knurled knob rotates the lens turret, selecting 10x, 60x or 200x magnification. The green button near the top of the unit is for taking a snapshot of what's on the PC screen. There are no other controls on the device, and to use it all you had to do was connect the blue cable to a free USB port on a Windows computer onto which the QX3 driver, control and simple photo editing software has been installed (included on CD supplied with microscope).

Sitting atop the rotating lens barrels there is a circuit board. A colour CCD image sensor is on the underside, with 320 x 240 pixel resolution. Two built-in lamps – one in the specimen platform and the other next to the image sensor) illuminate the slide from above and below. Incidentally the QX3 seen here is a first generation model, using tiny incandescent light bulbs; later versions used LEDs. This explains warnings stamped on the case, alerting parents and literate tots that parts close to the lamps can get ‘very warm’. The whole microscope/camera module detaches easily from the stand so it can be used hand-held, which could be useful for classroom demonstrations and so on, though it’s quite difficult to hold steady and almost impossible to use on 60x and 200x magnification.

The supplied software has the option to store images, with or without some cheesy special effects, and turn them into a slideshow. You don’t have to be eight years old to enjoy using it either, though the viewer program does look a little crude, compared with what today’s youngsters are accustomed to on their smartphones and tablets.

This QX3 was a review sample for one of the computer and games magazines I was working on at the time. It was briefly popular with my pre-teen children and may even have had a small part to play in my son’s future career path. However, at the time our home was awash with fancy hardware and software on test, including a lot of games and these proved even more enticing and after a few weeks of regular use the microscope ended up in a box in the loft. I was disappointed to discover that it would have nothing to do with any current or recent PC running Windows 7 or later. There are a couple of ways to get it going again though. The simplest method is to install Windows Virtual Machine (free from Microsoft) and load up a copy of XP – assuming you still have one – in effect you’re running Windows XP inside Win 7 or 10, and can install old programs and drivers as if it was an actual XP computer. Otherwise there are a number of updated drivers lurking on the web, though none of the ones I tried worked. It also runs quite smoothly on Linux, as a camera input, but without the control software. Image quality is pretty good considering the image sensor’s limited capabilities and the auto exposure systems do an excellent job of adjusting for changes in light levels and the reflectivity and colour of specimens. Although this one had been quite well used in its time the fact that it still worked wasn’t at all surprising. Build quality is outstanding and it is capable of standing up to a lot of rough treatment.

What Happened To It?

The QX3 and a number of other Intel Play products were developed in collaboration with toy maker Mattel in 1998. The joint venture, known as Smart Toy Lab, was a bold attempt to combine Intel’s chip and tech savvy with Mattel’s expertise in designing in marketing toys, potentially opening up new markets for both companies. The QX3 was the first product under the Intel Play banner. It was supposed to be followed by Play 2MeCam, a device fitted with an RF tag reader that allowed children to scan their toys, which would direct the PCs to visit websites linked to the toys. The original design proved too complex and fraught with problems over Internet safety and security. A modified Me2Cam was later released as a combined PC camera and gaming system, allowing the user to interact with a small number of specially written games with gestures and by ‘touching’ objects. In spite of the QX3 becoming the top selling multimedia toy of 1999, and several other innovative products reaching the market the Smart Lab project was closed down in 2002. It was sold to Prime Entertainment, who rebranded it as Digital Blue.

Intel Play QX3s and the QX5 – an upgraded QX3 developed by Digital Blue -- can still be found online, though it appears that production stopped some time ago. All of the models I have seen suggest that it is only compatible with Windows 98, ME, 2000 and XP. This makes them prehistoric, not to say practically useless in terms of the PC, smartphone and tablet technology of the past 15 - 20 years. Yes they can still be used with a bit of faffing around but it’s not much of a selling point when you consider that there are now countless digital microscopes and cameras available with vastly superior performance, selling for as little as £10.00. Nevertheless, the QX3 still has a lot of retro charm and is genuinely fun to play with, if only briefly. If you want a QX3 you shouldn’t have any trouble finding one on ebay for £10.00 or less. Sadly, and for the foreseeable future it won’t be much of an investment but much as I hate to say it, it wouldn’t take much to convert it into a rather fetching table lamp…

DUSTY DATA

First Seen: 1999

Original Price: £100

Value Today: £10 (0220

Features: CCD colour image sensor 320 x 240 pixels, 10x 60x & 200x optical magnification, moveable specimen platform, dual illuminators (miniature incandescent bulbs),

Power req: USB powered

Dimensions: 270 x 165 x 125mm

Weight: 800g

Made (assembled) in: China

Hen's Teeth (10 rarest): 6

Mullard OC Series Transistors 1952 – 1978

In a brief departure from dustygizmos’ usual format we’re looking at a single innovative and crucially important electronic component, used in the vast majority of British and European made radios, amplifiers, tape recorders and so on, from the mid to late nineteen fifties until the early seventies. It’s the transistor, specifically the legendary ‘OC’ series of Germanium junction transistors, the vast majority of them manufactured by Mullard, a UK subsidiary of the Dutch electronics giant Philips.

Mullard produced its first prototypes in 1952, barely four years after Bell Laboratories in the US invented the transistor. They were the OC50 and 51, which used the same ‘point contact’ construction as the original Bell transistors. However, they proved to be difficult and expensive, not to mention very fragile, so they never went into large scale production, A year later Mullard introduced the OC10, 11 and 12 which used artificially grown Germanium crystals, doped with various chemicals. These altered the crystals electrical conductivity to produce layers with differing characteristics. The crystals with ‘semiconducting ‘ properties were sliced into tiny slabs and connected to fine wires. The meeting points between the layers are known as ‘junctions’, led to the name ‘junction transistor’.

Skip this bit if you’re not a fan how-it-works stuff. Essentially junction transistors have three wires or connections, known as the Emitter, Base and Collector. Think of a transistor as a super-quick tap controlling the flow of gas or a liquid. The Emitter and Collector represent the inlet and outlet of the tap, and the Base is the twisty bit on top controlling the flow. In a transistor a large voltage or current passes between the Emitter and Collector and the Base i.e. the twisty bit, fed by a much smaller signal current that controls the flow. Transistors can therefore act as switches, by turning the flow on and off really quickly. This makes them useful controlling things and as we all know, computers are mostly composed of switches, billions of them, each one basically a transistor. However, transistors really came into their own as amplifying devices, turning small signals – applied to the Base into much larger signals by controlling the current flowing between the Emitter and Collector.

And we’re back, to the life and times of the OC series transistors. It only took a couple of years for Mullard (and other transistor manufacturers around the world) to iron out the kinks and wrinkles and figure out how to mass-produce these devices. They had become a commercial product and the fun could begin. Mullard got off to a flying start in 1954 by working out how to encapsulate their transistors in tiny round ended glass tubes. This eliminated at a stroke problems other makers were experiencing with other types of housing, which over time allowed air and moisture to get in. This could rapidly damage sensitive Germanium crystals and cause thermal instability.

Mullard's first commercial venture became one of the most popular, versatile and long-lived ranges of audio frequency transistors. They were the OC70, OC71 and OC72, easy to spot in their black painted glass housings and metal casings The three transistors were generally manufactured from single crystals then tested and selected for their specific properties. Transistors with low noise characteristics became OC70s, the OC71 was a standard all-purpose type and the OC72 could handle more power and fitted inside an aluminium cover to further improved heat dissipation.

Here’s a nerdy tidbit. Germanium crystals are light sensitive, hence the black paint on the glass encapsulation. Mullard exploited this effect by introducing a variant called the OCP71, also known as a Phototransistor. They were extensively used as light sensors and the electronic enthusiast magazines of the day were full of circuits and plans for light activated burglar alarms, electronic door openers, even light-based ‘walkie-talkies. Unfortunately OCP71s were horribly expensive, compared with standard OC71s, but it was discovered that you could scrape off the black paint on a bog standard OC71 to make a cheap OCP71. Both types were filled with a clear silicon gel. The story goes that Mullard got wise to the practice and changed the filling of OC71s to a lightproof paste. It turns out this was something of an urban myth. Allegedly the switch to an opaque paste was to improve heat dissipation and OC71s with the clear gel were actually rejected OCP71s so they either didn’t work as phototransistors, or the light-sensing performance was poor. For the record I recall using this trick to make a rudimentary light activated switch, and it worked very well indeed.

Throughout the 1950s Mullard continued to develop more advanced versions of the OC series transistor. The OC44 and OC45, which appeared in 1956, were designed to handle higher frequencies, which led to them becoming a familiar sight in early British made transistor radios. However, the original manufacturing process imposed limits on the frequencies junction transistors could handle. It wasn’t until 1958, when Mullard introduced the OC169 and OC171 – using a refined manufacturing technique -- that transistors finally found their way into high quality, British made radio receivers. At around this time Mullard were also making low noise transistors that could handle significantly higher currents. They were meant to be used in multiple stages, the smaller ones, known as ‘drivers’ controlling larger ones, housed inside ‘diamond’ shaped metal cases. These led to the first all-transistor ‘power amplifiers’ resulting in a new generation of high-quality audio components and ultimately the birth of the world-renowned British Hi-Fi industry

What Happened To Them?

As soon as Germanium transistors were developed that were capable of handling high currents and frequencies valves (or vacuum tubes as they call them across the pond) became virtually obsolete except for the most specialised applications. Transistors changed the world but low power Germanium types tended to be electrically fragile and easily damaged by high voltages and static discharges. Fortunately a more robust type of transistor was already in development by the early 1960s and highly purified silicon proved to be a vastly superior semiconductor replacement. Nevertheless Germanium transistors remained in production until the late 1970s and silicon was even used in OC series types like the OC201 and 207. However, to avoid confusion Mullard changed its component prefixes to AC for Germanium and BC for silicon.

There is a small community of collectors of vintage transistors and electronic components and very early Germanium types can sell for three and four figure sums. The big bucks are generally reserved for extremely rare prototypes, pre-production samples and short–lived or experimental devices. Don’t get too excited, though, they are not the sort of thing you’re likely to stumble across at a car boot sale, unless you are extremely lucky and know what you are looking at. Tens of millions of Germanium transistors were made so there is no shortage of them on ebay, either in NOS (new old stock) form, or inside old radios etc., but there are a few sought after types that can sell for several pounds. These include unused vintage transistors, especially if they come with their original packaging and more specifically OC44s and OC45s, which, thanks to their often-poor noise characteristics found their way into guitar ‘Fuzz’ boxes. The result is a very particular sound that can get some serious musicians quite excited…

DUSTY DATA

First Seen: 1952

Original Price: £5.00 – “0

Value Today: £50 – £1000 (0120)

Features: Low power audio, intermediate and radio frequency germanium junction transistors, glass and metal encapsulations

Power req: n/a

Dimensions: 14.4 x 4.9mm (30mm lead length)

Weight: 0.7g

Made (assembled) in: Netherlands, England, Germany & France

Hen's Teeth (10 rarest): 7

National WH-106 Body Hearing Aid.1975?

According to recent research hearing loss affects around one in six people living in the UK yet unlike many other common physical and age-related impairments, it’s prevalence is not always obvious. That is largely thanks to advances in technology, as opposed to major medical breakthroughs, though they have undoubtedly made significant contributions. Deafness often comes on slowly and sufferers, and those around them may only gradually become aware of its effects. Asking people to speak up, increasing the volume on TVs and radios or believing everyone is speaking quietly or indistinctly, can be early signs. However, over the years one of the most successful treatments for the common forms of deafness, like old age etc, has been the hearing aid. Essentially they are small amplifiers that boost sounds from a microphone to an earpiece worn by the sufferer. Hearing aids have always been at the cutting edge of the prevailing technology, from the earliest ear trumpets, to the latest micro in-ear digital hearing aids and ground-breaking treatments like cochlear implants, which can give even profoundly deaf sufferers a sense of sound.

Before we get started I have to say that I am fortunate enough to have reasonably good hearing, so far... Impairment and the many treatments is not something I know a great deal about, though I became a little wiser whilst researching this item. Nevertheless I apologise in advance for any gaffes and inaccuracies that may follow. As usual I welcome corrections and clarifications, which can be sent to the usual address..

I believe this National WH-106 ‘body worn' hearing aid dates from the mid to late seventies and almost certainly employs some of the (then) latest electronic components, it delivered the most up to date auditory enhancements whilst at the same time being as small as possible. I have been unable to find any references to this model anywhere on the web so the manufacturing date is based on two things: the electronic components inside the unit which are characteristic of the mid to late seventies and the various archivists and enthusiasts who meticulously catalogued subtle changes in the National name, typeface and logo designs. And if you think that’s a bit geeky, then you might be surprised to know that there is a lively vintage hearing aid collecting community, and it’s not hard to see why when you delve a little deeper into the subject’s long and sometimes quite bizarre history. If you are interested a good place to start is the Hearing Aid Museum.

Miniaturisation has always been one of the key design goals for hearing aids. There is of course a convenience factor in having the device as small and light as possible but I suspect the ultimate aim has been to make them as inconspicuous as possible. To that end a great deal of effort has gone into making them small enough to fit behind the ear, and more recently, inside the ear canal. They have also been built into spectacles and watches but the WH-106 belongs to the body worn category, where extreme miniaturisation isn’t such a big deal. This gives designers greater scope to make them more sensitive, louder, incorporate more advanced features and remove the need (and appetite) for expensive button cells. The WH-106 was meant to be clipped to a shirt or suit pocket and the amplified output fed to the ear through a skin-coloured cable and compact earpiece. There’s room inside the case for a feature called T-Coil. It’s an inductive loop system, essentially a short range wireless link that enables the user to hear sounds transmitted through a nearby antenna, installed in shops and ticket booths, cinemas, fitted inside telephones and even in homes (see Connevans LA5 Loop Amplifier).

As you can see from the photo above the WH-106 fits easily in a box of Tic-Tacs. It is powered by a single AA cell and there are just two controls, both on on the top panel. They're a rotary volume knob and a three-position switch for selecting power on, T-Coil operation and the onboard microphone. Inside there’s another three-way switch for adjusting sensitivity (effectively a tone control for setting treble response). The magnetic earpiece has a custom 2-pin plug that fits into a socket on the side, and it comes with a set of interchangeable adaptors, to suit different shapes and size of ear canal. The microphone, an early electret type, is mounted on the top panel, next to the function switch.

Delving deeper into the innards, the main circuit board is populated with the sort of small components found in pocket radios of the day. The only unusual parts are what look a lot like a pair of germanium point contact diodes – virtually obsolete by the mid 70s -- two ‘thin film’ modules (small multi-pinned, resin coated circuit boards) and what may turn out to be proprietary integrated circuit or microchip, or a ‘potted’ circuit module of some sort. Unfortunately the markings turn up nothing of relevance on web searches. It should be possible to work what they do by reverse engineering the circuit but that would be a job and a half and in the absence of any discrete transistors they are clearly concerned with amplification, audio processing and the T-Coil feature. Suffice it to say the whole thing is superbly well-made and built to last, which it has, though its survival is down to the former owner. Hearing aids like this tended to be expensive and because they were heavily relied upon, would have been well cared for.

Who that owner was and how it came to be on a stall at a midlands antiques fair is unknown, but it caught my eye immediately. Although it looks a bit like a miniature transistor radio I was fairly certain what it was straight away, and the very neat leather case it came with was clearly for keeping it safe when not in use, rather than to protect or carry it in. It appeared to be in excellent condition, though the small hole where the microphone should have been was occupied a mini jack socket. The mystery was solved when I found the missing mike module in the bottom of the leather box. It had been clumsily attached to a rubber bung and soldered to a short cable terminated with a jack plug. Presumably this was to allow the user to relocate it, to a more discrete location – no I don’t why either…

I had previously wandered into the vintage hearing aids section on ebay and knew that they could fetch a pretty penny so I wasn’t too hopeful about the asking price. However, it had been a bitterly cold day and the stallholder looked like he was keen to get home, or was aware of what the modified mike would do to its value, and accepted my offer of a fiver. Returning the mike to its original position took only a few minutes and the enlarged hole was tidied up with a small piece of micro-thin mesh. Inserting the battery produced a healthy dose of feedback suggesting everything was working. After backing off the volume to a more comfortable level it proved to be firing on all cylinders and a very effective audio amplifier, though it will have to wait for a more comprehensive road test by one of my hearing aid wearing friends.

What Happened To It?

National, founded in Japan in 1925, are a division of the massive Matsushita Corporation. The National name was widely used up until the mid 1980s when it became National Panasonic, and then just Panasonic for most of its consumer product operations.

As hearing aid technology has improved over the years there has been a shift from body worn to behind the ear and in-ear types though there is almost certainly still a market for larger, more powerful and specialised designs. No doubt some users simply don’t get on with micro aids, and prefer the simplicity of body worn types, so one way or another designs like the WH-106 haven’t gone away entirely.

Looking through the assortment of vintage hearing aids appearing on ebay of a similar vintage and feature set makes it difficult to say what this one might be worth. The range of prices is unexpectedly wide, from around £20 to £350 on the days I checked. Its clear that hearing aid collecting is a specialist pursuit and potentially dangerous ground for the unwary.

The apparent rarity of the National WH-106 counts in its favour, though the microphone mod may well be a turn-off for serious collectors so I’m going to value it, in its present post restoration condition, quite conservatively at £40.00. The bulk of buyers and sellers appear to be in the US, though there is a small number of UK sellers if you want to get involved, and prices are generally lower, and there are big savings to be has on shipping. Most of the models I have seen date from the fifties through to the eighties – arguably the golden era of the pre-digital hearing aid. However, there is another category of hearing aids that qualify as antiques and these include passive hearing devices, like ear trumpets from the eighteenth and nineteenth century through to purely electrical designs based on telephone technology, and valve based models, the earliest of which appeared in the 1920s and lasted until the early 50s. These are of considerable interest to a much wider group of collectors due to their increased rarity and historical importance so, inevitably, they command significantly higher prices.

DUSTY DATA

First Seen: 1975?

Original Price: £?

Value Today: £40.00 (1019)

Features: Body worn transistorised hearing aid, built in electret microphone, magnetic earpiece, T-Coil compatible, rotary volume control, 3-position sensitivity control

Power req: 1 x 1.5v AA cell

Dimensions: 70 x 43 x 18mm

Weight: 34g

Made (assembled) in: Japan

Hen's Teeth (10 rarest): 9

ISI Rapid Abnormality Indicator Type 4A, 1955?

Where to begin? In fact it all began with a loud ‘WTF’, or words to that effect, when I spotted this ISI Rapid Abnormality Indicator (Type 4A). It was at a small antique market, partly hidden in a cardboard box tangled up with other electrical odds and sodds. With a name like that I just couldn’t pass it by and the asking price of £5.00 seemed fair for something as weird and wonderful as I hoped it would it would turn out to be. I wasn’t wholly disappointed but it took a while to figure out exactly what sort of abnormality it indicates. I think have managed to work it out but to be honest I could be completely wrong, so here goes, and as always, feel free to set me right….

We’ll begin with a few blindingly obvious features. It comes in two parts, connected by a captive cable. The white box is clearly the power supply, with a hinged compartment for a battery of unknown type and voltage, and a second, smaller compartment containing power supply and regulator components – more about those shortly. The other part is the hand-held meter with what I take to be some sort of sensor apparatus inside. Oh yes, and it’s bright yellow. All attempts to discover more have failed. It’s a one-piece moulding, made out of some sort of tough plastic and I am reluctant to use aggressive methods to take it apart for fear of destroying it. The only obvious way to get at the innards is through the hole in the front for the meter but it appears to have been permanently bonded to the case.

I took this to be a clue to its purpose, suggesting that the meter is hermetically sealed to prevent the escape or ingress of liquids that might affect a measurement. The inside of the meter’s glass cover has become discoloured and originally I thought this might be due to some sort of chemical reaction with whatever was being tested. Labelling on the meter dial added to the idea that it was somehow concerned with analysing toxic or noxious substances. These include ‘Chloride %’ and the meter scale, which is calibrated 0-100 ‘MHOS x 10^-4. According to Wikipedia MHOS is a measurement of material hardness, not to be confused with MHOs, which is a measure of electrical conductance (the reciprocal and backward spelling of Ohm, the measure of electrical resistance). In the context of this instrument the latter definition sounds rather more likely, measuring the electrical properties of a liquid or gas.

The entry point for the gas or liquid being measured is on the top of the unit where there is a hemispherical depression, with a small hole in the base. Could it be designed to fit over and make a good seal with a similarly shaped hemispherical protuberance on whatever was being tested? Attached to the bottom of the handle is a plunger, designed to draw the gas or liquid into the abnormality indicator?

I came up with a manufacturing date of 1955 and this was loosely based on a couple things. Firstly the contents of the smaller battery box compartment. The silver cylindrical component is a Vibrator. Before you ask, it’s a small self-contained module that converts low voltage DC (6 volts, if the markings on the can are anything to go by) to a higher AC voltage. It does this with a pair of coils, one acts as an electromagnet, coupled to an interrupter switch – the bit that vibrates – which generates a continuously collapsing electromagnetic field that induces a higher voltage in the second coil. Before transistors arrived, in the late 1950s, vibrators were quite common in portable valve-based devices and instruments, like this one, with components that need high voltages. There are a few other passive parts in the power supply unit and these all look like mid 40s to late 50s items. The other clue to its age and what I thought might be another pointer to its intended application came from the one and only reference I could find web. It was just a photo, probably from an old ebay listing – too old to be in the archives, Just a few words from the description survived the only one of relevance was a mention that it had a Ministry of Defence (MOD) arrow stamp.

All of this led me to suppose that it may have some sort of highly specialised military application. I imagined it being used to test for chemical leakage on munitions, for example, which would explain the discolouration of the meter and it’s apparent rarity. But then I had another thought about the markings on the sides of the hand-held unit. They look like check boxes with numbered columns and these are labelled ‘COW’, LF, ‘RF’, ‘LH’ and ‘RH’. This was a real light-bulb moment. ‘Rs’ and ‘Ls’ might indicate Right and Left, and the ‘Fs’ and ‘Hs’ might just stand for ‘Front’ and ‘Hind’, and ‘COW’, which I originally took to be an obscure military acronym or short for cowling, or some such, might be exactly what it says, a cow, of the bovine persuasion, along with its assigned number. A quick google search using keywords ‘chloride’, ‘contamination’ and ‘milk’, produced numerous references to tests for salt levels in milk, and allowable levels, with reference to conductivity and mho units. It turns out that salt or sodium chloride, is one of a number of common adulterants that can be used to dishonestly increase its quality and fat levels. Suddenly it all started to makes sense, the hemispherical hollow on the top and plunger, used to take milk samples directly from a cow’s udder, the MHOs conductivity reading, the sealed, wipe-clean case and so on. Well, that’s my theory and I'll stick with it until someone tells me different.

Condition-wise it is in pretty good shape, it’s obviously designed to withstand rough usage and also well protected against moisture. Sadly the power supply is stone dead and all my tests suggest that the vibrator has failed. It’s a sealed module and taking it apart would be difficult without damaging the contents so it’s best left alone. Other parts have probably degraded with age but without being able to get at the sensor or whatever is inside the hand-held unit it will have to remain in its present inert, but quite presentable condition.

What Happened To It?

ISI or Industrial Scientific Instruments Ltd seem to have come and gone without trace. A couple of US and Indian companies with similar names turned up in a lengthy web search but none of them appeared to have any connections with whoever made this instrument. As you might have guessed testing for impurities in milk has moved on since the days of the Abnormality Indicator and now include a wide range of factors, including chemicals and microbial contaminants, as well as quality factors, like acidity, fat and vitamin content, which are all important in cheese making, for example. Comprehensive tests require a lot of fancy lab equipment but there is still a big demand for small, portable instruments that can be used in the field, as it were.

The big question, of course concerns its value and since I have absolutely no idea, I’ve put it at the fiver that I paid for this one. Although it is clearly unusual and this is the only one – apart from that ebay photo – known to exist I doubt very much that it’s the sort of thing any sane person would seek to collect There is a healthy market for vintage agricultural implements and artefacts but the Anomaly Indicator doesn’t seem to fit into any of the established categories. It doesn’t work, and even if it did it wouldn’t do anything especially useful that I can see; it wouldn’t even make a particularly interesting novelty table lamp but to a weird gadget collector -- the gadget, not me -- and with a name like that it has to be worth something, probably around £5.00…

DUSTY DATA

First Seen: 1955?

Original Price: £?

Value Today: £5.00 (0819)

Features: portable chloride contaminant measuring apparatus, analogue meter display, separate battery and power supply module, on/off switch, meter zero adjust knob

Power req. 6 volts DC proprietary battery?

Dimensions: 230 x 88 x 90mm (meter/sensor), 220 x 95 x 48mm (batt/vibro box)

Weight: 1.7kg

Made (assembled) in: Britain

Hen's Teeth (10 rarest): 9

Pulvelec Cabinet Battery No 10a, 1925

Here’s another candidate for dustygizmos’ ‘WGACA’ department, which, for newcomers and irregular visitors to the site is where we keep the what-goes-around

-comes-around vintage technology. In other words old gadgets that have been re-invented – sometimes several times over – and often touted as the next big thing.

Old is the operative word in the case of the Pulvelec Cabinet Battery No 10A. A label inside the case bears the date 1925 but its predecessors go way back, to the mid 1800s and apparently even earlier. More about that later on.

Essentially it’s a device for generating high voltages that are applied to the skin and body with the aim of curing a range of ailments. It’s a pretty extensive list too, here’s what the Pulvelec’s instruction leaflet reckons it’s good for:

Alopecia, acne, anaemia, faulty blood circulation, bladder and kidney troubles, constipation, indigestion, gastritis, muscular atrophy, neuritis, sciatica, neuralgia, neurasthenia, nervous exhaustion, paralysis, paraplegia, hemiplegia, spinal cord disorders, rheumatism, lumbago, arthritis, gout, nasal catarrh and middle ear catarrh.

As you may have noticed devices like this are not a common sight in today's medicine cabinets and doctor's surgeries and most, if not all of those maladies are still with us.

If you haven't already guessed it's a fine example of 19th century Quack medicine. But there's a twist. Whilst there is no way it's an effective treatment for most of the items on the list, self-administered electric shocks have proved to be a successful method of pain relief (TENS or transcutaneous electrical nerve stimulation); there are also modern electric shock machines for toning your muscles, dealing with spots, pimples and saggy skin, even energising dangly body parts -- you'll can work that one out yourself - not to mention numerous applications in mainstream medicine, including ECT or electro convulsive therapy, which is a recognised treatment for certain mental health conditions.

The somewhat ambiguous ‘Cabinet Battery’ name suggests that the makers were not entirely confident about marketing it as an authentic therapeutic medical instrument, though this appears to be a later development, in the 1920s. Earlier versions of this and rival devices were more forthcoming, with names like ‘Electro Rejuvenator’, ‘Electreat’, Electro Vigor’ and so on.

Generating several hundred volts is surprisingly easy, and only slightly dangerous as the currents involved are very low. The Pulvelec employs the most common method, using a simple transformer. Basically it’s two coils of wire wound around a cylindrical iron core. The innermost coil of thick wire, the primary winding, turns it into an electromagnet when it is connected to a power source. This attracts a small piece of metal, mounted on a piece of springy brass, which also acts as a switch. When the magnet pulls the brass strip it breaks the supply to the primary winding. The magnetic field surrounding the coil collapses, inducing a high voltage in the other coil, or secondary winding, which is made up of several thousand turns of much finer wire. The released spring contact re-makes the circuit and the process is repeated, at high speed, resulting in a loud buzz and a very decent 300 to 800 volts on the output terminal. Sliding the shiny metal cylinder covering the coil from side to side has the effect of damping the magnetic field, thereby controlling the output voltage.

When new the Pulvelec came with a variety of special attachments, for administering shocks to various parts of the body. These included metal wheels and rollers, conductive brushes, combs and wristbands. Sadly this one only had one of the two insulated wooden handles it was originally supplied with, and some decaying cotton covered wire, but it was enough to figure out how it worked and eventually get it working,

Needless to say it didn’t look anything like this when I found it, at a large antiques fair in Surrey. It was in a pile of junk, but the wooden box appeared to be a well made item, and although the contents were in a sorry looking state, it seemed to be reasonably intact and worth the £8.00 I ended up paying for it. It was well beyond a simple wash and brush up job so after taking a number of photos, to make sure everything went back where it came from, I stripped it down to its last nut, bolt and screw. The first and most important thing to check was the coil. If either winding were open or short circuit it would make getting it to work again a nightmare. Fortunately they were both intact and giving hopeful readings on the multimeter.

The wooden case just required a little elbow grease, paint stripper and sandpaper to remove the years of dirt and ancient lacquer, back to the bare wood. Once smoothed down with fine wire wool it was treated to two coats of Osmo Polyx oil, which did an excellent job of highlighting the grain and restoring the surface finish. All of the metalwork and parts cleaned up really well using my Dremel drill and some fine wire brushes; even the tatty cotton covered wire responded to some TLC and silicon spray, to the point where they could be used once again for the battery and accessory connections. The restored parts fitted together neatly and for the first time, possibly in decades. The previously detached front panel, on which the coil assembly is mounted, folded down properly when the case lid is raised. This revealed a rather neat feature and when the front of the case is raised to the stowage position the on/off switch presses against the base, automatically switching it off.

The last job was to renew all of the electrical connections after which it was hooked it up to my bench power supply, set to 3 volts, so see if anything happened. There were some sparks around the contact breaker but not enough movement to get it started. Raising the PSU output to 5 volts got it going and a reading 300 volts appeared on the multimeter connected to the probe terminals. Sliding the cylinder to the right, exposing the coil, stepped up the output to over 800 volts, at which point I backed off the supply, fearing that pushing it too hard might destroy the coil.

There is a serious lack of technical information about the batteries originally used to power these things. I suspect most of them were proprietary types that are no longer available. However, the compartment at the rear of the box, which appears to be for the battery, is just the right size for a 4.5 volt ‘126’ battery pack. This is at or close to the units operating voltage, which is why it appears in the photos but before anyone writes in to complain I doubt very much it is the correct type.

What Happened To It?

The manufacturing date of 1925 is based on the makers label inside the case, which says ‘Pulvermacher & Co. Established in 1848. Foremost in 1925’. Since manufacturer’s labels are rarely used to predict future events it is probably safe to assume that it is a year or two older than that. The first mention of the company’s founder, Isaac Pulvermacher, a physicist from Vienna, relates to his ‘Hydro-electric Belt’. This contraption consists of a belt holding a number of small batteries. It was first shown at the World’s Fair at London’s Crystal Palace in 1851. Apparently it applied a ‘titillating’ current to the skin. If contemporary reports are to believed it was bought by celebrity uses, including Charles Dickens. Apparently he was advised to try it, to relieve the foot pain he suffered on his reading tours in the 1860s. It’s not certain if he actually tried it as he died soon after placing the order. For the record Pulvermacher didn’t invent the electric shock machine and there are mentions of electric shock treatment going as far back as 48 BC. It seems that Roman Emperor Claudius’s doctor recommended applying electric eels to his head as a way of combating the pain of migraines. Most likely this would have been a permanent fix…

The late 1800s, through to the 1930s was the heyday of Quack remedy machines like the Battery Cabinet. There were hundreds of different designs. Many, like the Pulvelec use transformers, others have hand-cranked generators or magnetos, or simply a large number of interconnected batteries. Electric shock boxes of all types appeal to a very wide assortment collectors. They include quack medicine enthusiasts, those interested in Victorian scientific, medical and electrical instruments and not forgetting Steampunk fans. The latter are especially taken by things in wooden boxes with lots of shiny brassware, switches and dials.

They all have value, and fine and unusually elaborate examples can change hands for hundreds of pounds. This humble little box isn’t an especially rare example, though, and it seems that quite a few of them were made. I've briefly monitored prices on ebay and they have varied widely between as little as £25 up to £100, so a fixer-upper like this one could be quite a good investment. If you don’t like getting your hands dirty and taking on a potentially challenging restoration job then be prepared to pay quite a bit more for a presentable one that works and comes with all of its accessories. Either way, my last piece of advice, gained from personal experience, is don’t try it on yourself...!

DUSTY DATA

First Seen: 1925

Original Price: £6 6s

Value Today: £40.00 (0719)

Features: therapeutic high voltage generator, adjustable output approx 300 – 800 volts, interchangeable contact heads & wristband, automatic switch-off, leather carry handle

Power req. 6 volt dry cell?

Dimensions: 155 x 130 x 130mm

Weight: 1kg

Nattex Copper Forming Dental Outfit, 1960?

Here’s a gadget to get your teeth into, or rather, get your (false) teeth out of, had you been around in the fifties and sixties. At least that’s my best and only guess about what the Nattex Copper Forming Dental Outfit was designed to do. So let’s begin with some certainties. It was made in England by Cottrell & Company, located in London W1. The date of manufacture is a little harder to gauge but the components inside the box strongly suggest that it was made somewhere between the mid fifties and the early sixties. Now for the big one, what on earth is it for?

I welcome clarification from anyone who actually knows, or has used one of these things but at this point all I can say for sure is that it is a variable mains-powered low voltage DC power supply, presumably used for electroplating copper, in some process involved in the manufacture of dentures. The power supply part isn’t in doubt but the only evidence I have for the latter assumption, that it has something to do with dentistry, is in the engraved label on the front panel. That and the three terminals on the front, which look like they might be for connecting plating bath electrodes; the meter, which shows current flow, and the variable control that probably adjusts the speed of the process.

Web searches using combinations of keywords including ‘Nattex’, ‘Cottrell & Company’, and ‘Copper Forming Dental’ drew an almost complete blank. This is clearly a rare and very unusual piece of equipment and it also suggests that Cottrell & Co disappeared or were taken over some time ago. The one and only lead was a possible connection to a present day company called Wrights Dental. The Cottrell name is linked with Wrights but their website makes no mention of a past merger or takeover and at the time of writing I am waiting to hear from them if there is any connection. Updates to follow if they or anyone else responds.

The front panel controls include a three-position range switch for the meter, labelled x10, x5 and x1. There’s an on/off switch and indicator lamp for the mains supply and a knob connected to a multi-turn variable resistor or rheostat that controls current flow. Inside the case there are only three main components, a mains transformer, a finned Selenium rectifier, and the heavy-duty rheostat. The Selenium rectifier was the key to dating the device. They were commonplace in mains-powered electrical equipment up until the early 1960s when they were replaced by silicon diodes; this was no loss, believe me! Selenium rectifiers were evil things with a limited life, and when they failed -- which was all the time -- they emitted a foul and long-lasting smell. To be fair it did make finding some types of fault a lot easier... The rectifier’s job is to convert the low voltage AC coming from the transformer’s secondary winding into a DC voltage. After passing through the rheostat, the voltage ends up on the output terminals on the front. You can’t see it from the photos but that rheostat is quite a thing. Basically it’s an insulated tube, covered in a winding of resistance wire. A screw-driven contact, connected to the knob on the front panel, travels up and down the tube, varying the resistance between the moving contact and two ends of the winding as it goes.

And so to it’s most recent and only known history, which began when it came into my possession, at a large Midlands antique fair. I spotted it fairly soon after arrival but passed it by as it looked a bit boring and there was bound to be many more interesting things to buy. There weren’t, so I returned to the stall just before leaving and wasn’t at all surprised to see it was still there. After a brief haggle the stallholder, who, like me, had no idea what it was settled on £8.00. That was a bit more than I wanted to pay but it had been a fairly quiet day and even if it was a total write-off there might be some useful vintage parts inside the box.

The case paintwork was in a terrible state but it responded well to a strip down, a good clean up and a quick respray with some white car paint. Inside it was just a bit dusty. Although everything appeared to be in good order there was no way I was going to connect it to the mains. The wiring is a scary rats-nest and there are simply too many things that can go wrong; I’ve had my fair share of mains jolts and a blown Selenium rectifier is not something I ever want to smell again…

What Happened To It?

This is all conjecture but I assume that Cottrell & Company of London W1 disappeared or was taken over 30 or 40 years ago as there is no record of the business or any of its products anywhere on the web; at least none that I could find. Equally there’s nothing about Nattax or Copper Forming, in relation to dentistry or denture manufacture, so it seems likely that this was a short-lived fad in the world of false teeth fabrication or replaced by some other processes. It is possible that this is the only one of its kind still in existence and in an ideal world it should be worth a great deal of money. Sadly that is rarely the case, as least as far as weird old gadgets are concerned. So unless an eccentrically wealthy collector of vintage dental apparatus wants to make me an offer, my valuation of £10, is probably not far off the mark. To be brutally honest it is practically useless, however, I can see a way of making it worth a few bob. Whilst I normally condemn the conversion of vintage items into wacky retro table lamps, in this case I might make an exception. It wouldn’t be too difficult to do and relatively easy to make the modifications non-destructive and reversible – in case it does turn out to be a valuable artefact. It should also be possible to give the knobs, switch and indicator lamp something useful to do by incorporating a dimmer switch, and maybe even get that meter moving again, turning dull-as-ditchwater dental into funky ornamental...

DUSTY DATA

First Seen: 1960?

Original Price: £?

Value Today: £10 (0619)

Features: variable DC power supply, selenium rectifier, rheostat, 0 – 100mA current meter, range switch, power on warning light

Power req. 230VAC

Dimensions: 260 x 168 x128 mm

Weight: 1.8kg

Made (assembled) in: England

Hen's Teeth (10 rarest): 9

Hohner 9806 Organetta ‘Table’ Organ, 1958

So far musical instruments have been few and far between in dustygizmos. This is not due to any particular prejudice, it’s just that interesting vintage instruments – relevant to these pages -- tend to be quite rare, expensive, or both. Even the less diverting ones are not that common but every so often something weird and wonderful (and cheap...) turns up and this Hohner Organetta, spotted at a car boot sale, was definitely hard to miss.

It’s clear from the shape and compact keyboard that it’s an organ of some kind but the styling and lack of controls suggests something either very basic, or from a time before digital electronics and LCD displays. Both are true in this case; it dates from the late 1950s and it’s a small portable or ‘table’ electric organ. It’s not quite a toy but it might well have been the kind of thing a youngster would have been given to learn or practice on. Note the word ‘electric’, no electronic circuitry is involved in the note making process. It’s basically a wind instrument, and if you are familiar with Hohner, you will know they’re a world-renowned manufacturer of mouth organs. That’s basically what the Organetta is, a giant mouth organ or Harmonica, to give it its proper name, but instead of human puff it has a mains powered motor driving a fan blowing air into a compartmented wooden box, fitted with vibrating metal reeds. This contrasts with conventional wind-driven organs, which blow air into individual tuned ‘pipes’. By the way an ‘Organetto’ is a fourteenth century Italian word for a portable pipe organ – thanks to Wikipedia for that little nugget…

The keyboard covers two and a half octaves, which is more than enough to bash out a few recognisable tunes and of course it is polyphonic, which means you can play two or more notes simultaneously. There is only one control, and it’s not an on/off switch. In fact it doesn’t have one – you may be able to spot the control running along the front edge, below the keyboard. It’s a sliding lever that restricts the airflow to the fan. It’s basically a crude, but effective, volume adjustment. The case is beautifully made from hardwood, and like a fine piano, it is heavily lacquered to a mirror like finish, though why it was given that lurid green paint job is anyone’s guess.

On the top of the case there’s a folding music stand, and on the underside, a green metal box houses the fan motor. It seems there was no room inside so in order for the Organetta to stand upright on a flat surface, and allow room for the sound to escape through vents on the underside, the makers fitted three short tubular metal legs. Unfortunately two of them were missing on this one but it’s a very simple matter to fabricate replacements from some thin pipe.

With the case top removed it’s easy to see how it works. Air blown from the fan is directed into a chamber beneath the ‘mouth organ’ box, which runs the width of the instrument. The keys are coupled to small pads that uncover holes on the top of each compartment when pressed, allowing air to flow through the metal reeds (see above), producing the individual notes. It’s an elegantly simple and clever design with very little to go wrong.

At the damp and dismal boot sale where I found it my first impression was that it was a large plastic toy, but the styling was unusual and the Hohner badge caught my eye. Closer inspection revealed a hard wood base, metal fittings, mains cable and a quality case and keyboard; this was no cheap plastic toy. I still wasn’t entirely sure what it was, but it looked unusual enough to make me want to find out more. The stallholder apparently has no idea about what it was either and the opening pitch of £10 was quickly whittled down to a more acceptable £5.00. Apart from the missing feet it appeared to be in excellent condition. The case was clean with no scratches or dinks and the few light marks on the keys cleaned off easily. Judging by the state of the innards it had never been opened and the accumulated household dust and debris was removed with a soft paintbrush. The wiring checked out and the motor turned freely so there was nothing for it but to plug it in. At first there was nothing, then after a few seconds the motor got up to speed and pressing the keys produced a full range of notes. One or two keys were not seating properly but this was fixed by gently bending the actuator rods and it is now playing and sounding as good as the day it was made.

What Happened To It?

The German company Hohner have been in the musical instrument business since 1857. It was founded by one Matthias Hohner who began by making Harmonicas. Within a few years the company had become the world’s largest manufacturer of mouth organs.

Over the years Hohner developed a range of wind-driven instruments. These included accordions and melodeons and by the 1950s it had begun diversifying and building electric and acoustic guitars. During the late 50s Hohner started making larger organs and it was around this time the Organetta appeared. During the 1960s Hohner progressed into electronic keyboards and synthesisers. They’re still at it, with a long and impressive list of famous names -- including The Beatles, Bob Dylan and Stevie Wonder, to name just a few -- using or lending their names to special edition instruments.

Green Organettas – and that seems to be the only colour used on this model – turn up on ebay from time to time but it’s difficult to get a handle on prices. These are exceptionally well-made and very useable musical instrument but prices seem rather modest, typically between £50 and £80. That’s not a lot for such an unusual item and by rights examples in good condition and full working order should be going for a fair bit more.

For some reason later models, like the Organetta 3 (early 60s?) – also wind driven, but with a grille on the top of the sound box -- seem to attract more interest and higher prices. Possibly they are a little louder and regarded as more functional. It shouldn’t matter, though, this one is loud enough for personal use, and it wouldn’t be difficult to mike it up. My advice to bands seeking an unusual cheesy sound and distinctive look is to get one! Just make sure it’s prominently featured in the video, and hopefully my £5.00 will turn into a worthwhile investment.

DUSTY DATA

First Seen: 1958

Original Price: £30?

Value Today: £50 (1118)

Features Wind driven miniature polyphonic organ, 2½-octave keyboard, mechanical volume, folding music stand, lacquered hardwood case

Power req. 220 volts AC mains

Dimensions: 410 x 250 x 130mm

Weight: 3.4kg

Made (assembled) in: Germany

Hen's Teeth (10 rarest) 7

My Power 25-Watt Megaphone, 1970

Sooner or later it will come in handy. At least that’s what I tell myself (and the missus) because quite frankly its difficult to justify owning a megaphone, let alone two of them, but mark my words, one day… To be fair megaphones, also known as loud hailers and bullhorns, do have their uses. The plus points include being a powerful crowd controlling tool at impromptu and low-rent (PA-less) public events and gatherings. They’re also useful for persuading bank robbers to come out with their hands up, and persuade twitchy roof-jumpers not to do it. I can also vouch for their efficacy for making trespassing cats to vacate your property. On the minus side they’re a very quick way of annoying next-door neighbours, and they cost a bomb to run, draining a set of eight ‘C’ cells in just a few minutes; at least that’s one of the major drawbacks of this My Power 25-watt megaphone, especially when playing with the built-in siren.

This model, which superficially looks a lot like the Eagle International Loudhailer, has a maximum output of 25 watts. It may not sound much, but the horn is designed to concentrate and direct the sound and according to some specs I found for a similar model, it can be heard up to a kilometre away. You’ll believe it if you are ever daft enough to stand directly in front of it… The similarities to the Eagle and many other loud hailers are mostly due to the fact that over the years megaphones have evolved into this familiar form, with the horn speaker at the front, a microphone at the back, and a handle with a trigger switch at the balance point, under the middle section, which houses the amplifier and batteries. On this model, and many others, the microphone is detachable, so the megaphone can be conveniently worn on the hip, slung from its shoulder strap. The mike also houses a second microphone capsule. This is wired to in anti-phase (back to front) to the main microphone, presumably as a feedback reduction measure. Whilst we’re with the microphone, it also has a rotary level control, which turns out to be the primary weapon against howl-round. The best feature, however, is the siren. It’s a real old-school US police siren, none of your trendy two-tones or whoop-whoop jobbies, it’s a proper rising and falling howl, guaranteed to get your audience’s attention.

Opening the battery cover reveals a pair of hefty power transistors. These are mounted on a removable module that contains the amplifier PCB and the contacts for the batteries. There are 8 transistors in a simple push-pull configuration and the fact that most of them are germanium types puts the probable date of manufacture somewhere between the mid sixties and late seventies. Build quality is good; it’s designed to withstand the knocks and drops of portable use in the great outdoors so a lot of attention has been paid to keeping out moisture. It is very easy to use; there’s no need to consult the manual, not that this one came with any, though it might have come in handy when I first tried to power it up.

I find it wise to assume that stallholders at car boot sales almost always tell porky-pies when it comes to the condition of their wares. I wasn’t surprised, therefore, when the nice old lady who I bought this one from for £3.00, solemnly promised that it was in good working order when she left the house that morning, in spite of one of the battery contact springs being clearly missing... In my experience stallholders peddling battery-powered devices that actually work will put in a set of batteries, to prove the point.

Obviously it didn’t it work and there was no way it could have done so for at least a decade, thanks to my old enemy, a leaky battery. It hadn’t been too serious, though and a few drops of acidic goop had eaten away a

rivet holding the spring in place. The leaky battery must have been removed fairly quickly after it had been discovered so the damage was limited. There had clearly been no attempt to use it for some years and the contact pins on the bespoke 2-pin external power connector were coated with a thin film of rust. That was confirmed by several generations of dead spiders inside the unit (what do they eat?). After a general clearout I hooked it up to a bench power supply and it gradually came back to life as the electrolytic caps re-formed (another sure sigh it had been dormant for years). The amp perked up quite quickly but the siren took a while to get going before it managed a continuous howl. I was able to make up a new contact spring from one salvaged from an old torch. It took a while to sort out the battery power, though due to some light corrosion on the other contact rivets and pads but now it’s fully functional, very loud and ready to go.

What Happened To It?

The My Power brand, just about visible on a faded sticker on the side of the main unit, is unknown to me or -- it seems -- the Internet. I am inclined to think that it came from the same factory making Eagle branded products and I have seen several near identical models, but with different names and logos suggesting it has been widely badge-engineered. This isn’t a surprise and it is likely that there are now, and has only ever been a handful of companies making what is a fairly specialised product with a very limited market.

Over the years megaphones haven’t changed very much and modern ones are not that different to this one, though for a given size they tend to pack in more powerful amplifiers and extra features, like a recording facility. Price wise they cost about the same nowadays, relatively speaking, as they did 50 years ago. That is reflected in the current value of vintage models, which is next to nothing to maybe £20 to £30 for one in good shape that still works. Real old-timers, from the 40s or 50s do have some value, though, but they appear to be few and far between on auction sites like ebay. There does seem to be a small collectors market in the US, though but the big money is reserved for unpowered – i.e. shout-through – megaphones adorned with advertising slogans, sports team logos, TV and movie characters and so on. If you want to become a collector the good news is you won’t find too much in the way of competition, but you’ll be doing it for the love of the technology, rather then a way to make money. Nevertheless, never pass up the chance to own one – especially if it is selling for less than a fiver. A megaphone is one of those things that you think you’ll never need, until the day you do, then you’ll wonder how you ever got by without one.

DUSTY DATA

First Seen: 1970?

Original Price: £30?

Value Today: £10.00 (1018)

Features 25 watts output, 8-transistor amplifier, built-in siren, detachable feedback cancelling microphone, 2 x PTT switches (pistol grip & microphone), mic volume, external power socket, carry strap

Power req. 8 x 1.5-volt C cells

Dimensions: 370 x 225 x 300mm

Weight: 1.9kg

Made (assembled) in: Japan

Hen's Teeth (10 rarest) 7

Airlite 62 Binaural Headset (1985)

If you think paying £200 or more for a pair of stereo headphones is a bit stiff then you’ve clearly had no dealings with civil aviation or the military. They routinely pay twice as much as that for what in civvy street would be regarded as a rather basic set of cans. What’s more, most of them are wired for mono sound and Hi-Fi buffs wouldn’t touch them with a bargepole. Usually the only obvious differences between headphones for listening to music and military or aviation headsets is the addition of a microphone, and the rather austere, often brutal design, but don’t be fooled. The lack of any obvious padding or fancy-sounding comfort aids doesn’t mean they are uncomfortable to wear. Quite the opposite. In many circumstances they will be worn for hours on end, and taking them off simply isn’t an option when the messages the wearer is meant to be listening to responding to is concerned with flight safety or maybe something really serious…

The Airlite 62’s featured here is one of the all-time classics. This model has been in production for more than 40 years, which suggests the manufacturers, UK-based Clement Clarke International got a lot of things right from the beginning. What made the Airlite 62 particularly popular with aviation and military users over the years was their adaptability. Scores of microphone and twin or single earphone combinations are available, along with numerous wiring and plug configurations, add-ons and accessories, but above all it is their reliability and durability that contributed to their longevity.

Build quality is on another level; they’re made to withstand constant use, often in harsh conditions, and that means using the toughest, lightest materials, and simple construction so there’s less to go wrong, but when it does, it’s easy to fix, in the field, if necessary. For example, the headphone capsules are held in place by a simple clip and the microphone module is mounted in a snap-in holder and both can be changed in a matter of seconds. The same goes for the padded headband, and since they are likely to be shared by several users, or worn in dirty or unhygienic conditions, it has easily replaceable outer cotton covers. There are a good number of adjustments, to make them more comfortable. The springy wire headband can be lightly bent to accommodate different head sizes; the earpieces slide up and down on the headband frame and it’s worth mentioning that the earphones have removable gel-filled cushions. Speaking of which, the ear cups are large enough to cover the whole of the outer ear, vitally important in noisy environments like aircraft and armoured vehicles.

The headset shown here dates from the mid 80s and is fitted with 300-ohm magnetic type earphones but 600 ohm magnetic and moving coil types are also available. It has an electret microphone and there’s an even wider choice of alternatives, including 300 moving coil and rocking armature types. Noise cancelling moving coil and electrets, Mu Metal shielded models with increased immunity to strong magnetic fields, amplified electrets and even old-school carbon mics. It came with an external microphone that plugs into a 3-pin Amphenol socket on the side of the mic boom earphone. This looks like it is designed to attach to an oxygen mask. The only slightly mysterious feature is the 6-pole 7.5mm jack plug on the end of the 2-metre long connecting cable. At first glance it looks like a standard NATO connector, or maybe a helicopter type plug but there are too many contacts. It’s definitely not meant for GA (general aviation – light aircraft), which still favours a twin jack arrangement, so if anyone can identify it, please let me know.

Unlike most things appearing in dustygizmos this one came from an actual shop, and a remarkable one at that in Lincoln (J. Birkett in Steep Hill, down from the Cathedral). They specialise in vintage radio and electronics and a lot of interesting avionics devices. There’s always something in the window, or inside that I didn’t know I needed and can’t bear to leave behind. These Airlites were a real bargain at just £5.00 and it took a great deal of will power (and a glaring missus) not to buy more. They were clean, in only slightly used condition, and good working order. My intention was to modify them for general aviation use but somehow they ended up in the to-do box, but I definitely will get around to it one day.

What Happened To It?

Clement Clarke started out making and supplying aviation headsets in the 1950s. Nowadays they’re called Clement Clarke Communications and are part of the MEL Group of aviation specialist companies. The Airlite 62 along with several other aviation headset and microphones are still in production and whilst there have been a number of modifications over the years they are recognisably based on the original design. Prices vary enormously but if you want a new one you can expect to pay the thick end of £400 for a basic configuration. On the second-hand market, as this one ably demonstrates, they can sell for as little £5.00, up to £100 or more for one in tip-top condition and configured for GA use, or a specific aircraft type. To be honest it’s not a very big market and prices in general tend towards the lower end of the range but you don’t need an aircraft to use one. There are several articles on the web showing how to modify them for more earthly applications, like computer gaming and ham radio. I don’t think they have much of a future in home audio or Hi-Fi; cramming in decent quality drivers could be quite challenging but I have no doubt someone, somewhere has tried it.

DUSTY DATA

First Seen: 1975?

Original Price: £400?

Value Today: £30 (0818)

Features: Binaural (twin) cushioned earphones (magnetic type 300 ohm impedance), adjustable boom microphone with detachable/interchangeable mic cartridge (electret), external mic connector, adjustable cushioned headband, 6-pole 5.5mm jack connector

Power req. n/a

Dimensions: 220 x 90 x 240mm

Weight: 420g

Made (assembled) in: UK

Hen's Teeth (10 rarest): 5

Viking ‘Sol Invictus’ Metal Detector, 1975?

Metal detecting has always had a slightly nerdy reputation, but it’s easy to understand the appeal when (very) occasionally a lucky detectorist unearths a historic or valuable artefact or better yet, a hoard of gold coins. In reality the vast majority of amateur metal detector owners are lucky to find anything more exciting than a few ring-pulls and some loose change, but for the determined few who put in the time and effort there’s always the chance of striking it rich…

Nowadays it can be a very expensive business with top-end equipment selling for thousands of pounds; but back in the 1970s, when this Viking Sol Invictus model first appeared, it was an altogether more modest hobby. The 70s and 80s was one of metal detecting’s periodic golden ages, with dozens of affordably priced models coming onto the market. This was due, at least in part, to advances in electronics and rapidly falling prices thanks to the efforts of far-Eastern manufacturers. However, for once detectors from British companies, like Viking were establishing a strong presence in the market, often with high performance (though not always very pretty) designs like this one from Viking.

Incidentally, the name ‘Sol Invictus’ (unconquered Sun) refers to a Roman Sun god and his likeness, along with the emperor of the day often appeared on Roman coins, and the sticky label on the front of this detector.

It looks deceptively simple; essentially it is a metal tube, bent at one end to form a handle, with a circular waterproof detector head, containing a pair of coils, on the other end. A plastic box houses the electronics and a battery, and this is mounted near the top of the pole. There are just two controls, one for power On/Off and Fine Tuning, the other for Course (sic) Tuning. It has a built-in loudspeaker, or if you want to avoid scaring the horses, there’s a standard jack socket for a pair of headphones. Setup takes just a few moments; after switch on the Coarse Tuning control is adjusted to compensate for ground conditions (moisture, minerals etc) by turning it to the point where the rasping tone from the speaker completely disappears. The fine tune control is then used to set it to just above the tone’s cut-off point. When the detector head passes over anything made of metal it disrupts the magnetic field between the two coils and produces a rising tone that falls off as it moves away. With practice it is possible to determine the approximate size, shape and even the depth of the metal object detected.

The design and construction of the hardware is relatively crude, even by the standards of the time. It looks almost hand made, the sort of thing that a hobbyist might put together in their garden shed, which may not be too far off the mark as it was almost certainly one of Viking’s earliest products. In spite of the lack of polish it is sturdily built, light, well balanced and in contrast to the rest of it, the circuit board is a professional looking item, using what was then state of the art components.

I spotted this one at a large open air antiques fair in the Midlands; it was hard to miss, looking decidedly out of place underneath a trestle table groaning with lots of fancy, and expensive, glassware. It turned out to be a relic from the stallholder’s youth who, like most would-be metal detectorists, gave up on it quite early on. He clearly had no emotional attachment with it and readily accepted my counter offer of £2.00 to his initial asking price of £10. It was in a bit of a state, though, and looked like it had spent the past several decades gathering dust in his garage. The layers of grime were so thick the metal and plastic parts all looked the same dull grey colour and If I hadn’t bought it I suspect it’s final destination would have been the rubbish bin.

Luckily it was the sort of grime that responded well to a rub down with household detergents and a scouring sponge. The metal pole regained its shine with the application of Brasso, elbow grease and several yellow dusters. The plastic housings for the coil and electronics had done an excellent job of protecting the innards from moisture and all it needed to get it going was a few squirts of contact cleaner on the two tuning controls. It works, probably as well as the day it was made, and was able to detect a 5-pence piece at a distance of 5cm; 2cm when buried in light soil. Having comprehensively swept my back garden with metal detectors in the past I wasn’t hopeful of finding anything new but thanks to some recent weeding I found a new bare patch to explore and swiftly located a long-lost teaspoon buried at a depth of around 10cm and closer to the surface, a badly decomposed pre-decimal penny, so it’s already starting to pay its way…

What Happened To It?

Metal detectors have been around for a surprisingly long time, since 1881 in fact, when Alexander Graham Bell – of telephone inventing fame -- designed a machine to locate a bullet lodged inside US President James Garfield. He had been shot in an attempted assassination but unfortunately it wasn’t found in time. Apparently Bell’s ‘Induction Balance’ apparatus was confused by the springs in the bed he was lying on and Garfield later died of an infection from the wound. The first purpose-designed portable instruments appeared in the 1930s and developments came thick and fast during and after the Second World War as they were used by the military to find and clear mines.

The next significant advance in the technology came in the 1950s, following the development of the transistor in 1947. This rapidly led to many new and increasingly advanced systems for locating and identifying buried metal objects, though without doubt the biggest impact of the transistor in the early days was to bring down prices and turn what was previously a highly specialised military and industrial tool into an inexpensive consumer product.

Viking started making metal detectors in the1970s and they’re still at it, with some smart looking and keenly priced designs, aimed at both recreational and industrial users. The story behind this Sol Invictus model is still a bit vague, at the time of writing the company had yet to respond to my enquiries regarding its official model designation, launch date and subsequent replacement but if and when I hear from them I’ll include an update.

Collecting vintage metal detectors has yet to take off as a hobby in its own right but there is definitely a healthy market for ex-military equipment, especially valve-based designs from WW II and subsequent conflicts. Metal detectors from the 60s onwards do not generate much, if any interest, yet they were an important part of the story of this interesting technology. Moreover, providing they work, some models, and this includes this early Viking, can still earn their keep. The lack of demand for older examples also means prices are low and its not unknown for disillusioned owners to part with relatively recent and much more advanced models at car boot sales for just a few pounds.

DUSTY DATA

First Seen: 1975?

Original Price: £25.00?

Value Today: £5.00 (0618)

Features: Twin-coil VLF type detector, rotary controls: On/Off & Fine Tune, Course (Coarse) Tuning, standard Jack headphone socket, 55mm speaker

Power req. 1 x 9 volt PP3 battery

Dimensions: length: 860mm, search head: 165 x 20mm, main unit: 230 x 60 x 70mm

Weight: 1kg

Made (assembled) in: England

Hen's Teeth (10 rarest) 8

Connevans LA5 Loop Amplifier, 1983

Unless you wear a hearing aid this rather nondescript looking box, otherwise known as the Connevans LA5 Loop Amplifier probably won’t mean that much to you, but there is a very fair chance that it, or more likely, one of it’s descendants might one day make your life a little easier. The odds of that happening are depressingly high. Currently around 9 million or 1 in 7 people in the UK have some sort of hearing loss; it rises to 1 in 3 for those between 60 and 70, and a staggering 3 out of 4 for the over 70s.

So what, you might ask, has the LA5 got to do with your current or likely future deafness? Well, unless you are hard of hearing you probably won’t have noticed, or paid much attention to the blue ear-shaped logos dotted around bank counters, on public transport, in cinemas, theatres and conference halls, to name just a few of the places where they can be found. They tell people with hearing aids, fitted with a feature called a Telecoil or T-Coil, to switch it on, and they should then be able to clearly hear what the person behind the counter, in the ticket office, kiosk and so on, is saying. The LA5 is a piece of kit that makes it possible. It’s an induction loop transmitter and the idea is audio, typically from a microphone -- other sources are possible, which we’ll come to in a moment -- is amplified and passed into a small coil or long loop of wire close to where the person with the hearing aid is standing or seated, as indicated by the hearing loop logo. The coil or loop generates a weak magnetic field, modulated in intensity by the sound from the microphone, and this is picked up by the T-coil in the hearing aid and converted back into sound.

The LA5 is a domestic version of the T-Coil Induction Loop amplifiers used in public areas. The idea is people with hearing difficulties install an LA5 in their home, and connect the input to the audio output of their TV or home entertainment system, so they can listen to these devices without having to turn the volume up high and risk annoying other members of the household. The technology is fairly straightforward. Inside the box there’s a mains power supply and a purpose-designed audio amplifier. It has two input jacks, one for line-level signals from an audio device, the other for a high-impedance microphone. There are three output terminals, for two induction loops, which are simply several metres of wire, usually running around the walls of the room in which it is to be used. There’s only one control, the large on/off level or volume knob on the front panel, and a single red power on indicator lamp.

Build quality is unusually good with everything mounted on a sturdy steel chassis, encased in a veneered wooden surround. The single PCB contains all of the power supply and amplifier components, which, for the record uses a pair of common chips for the pre-amp and power amp stages (TL071 & TBA810). Incidentally, the loops are meant to have an impedance of 2.5 ohms, or around a third that of a typical hi-fi loudspeaker (8 ohm).

This LA5 came from a local car boot sale and the fact that it doesn’t look very interesting, and the seller didn’t know anything about it accounted for the asking price of just £1.00. I must admit that I had only the vaguest idea about what it was for, but that was what interested me. Even if it turned out to be totally useless, it was worth a quid for the smart little box and a mains plug… The condition was generally very good; all it needed was a clean up and a minor repair to replace a missing piece of veneer on the wooden case. With a coat of good quality wax polish it now looks almost as good as new. I am fairly sure that it works, at least there was no bangs, smoke or nasty smells when it was powered up. Unfortunately I have been unable to fully test it though, being currently lucky enough to have very good hearing. The handful of sufferers that I know either shout and ask me to speak up a lot, or have tiny in-ear digital hearing aids that do not have the T-Coil feature.

What Happened To It?

Connevans, by Royal Appointment as suppliers of audio equipment to Her Maj., no less, are still actively engaged in manufacturing and supplying equipment for the hard of hearing, as well as other disabilities. They also supply schools and colleges and if you ever find yourself needing a several times life size anatomical model of the ear, eye, brain or larynx you’ll know where to go… By the way, the name comes from its founders, Connie and Meurig Evans, who founded the company in 1961. It remains a family concern and is now based in Merstham in Surrey.

I can be sure that the LA5 shown here was made in 1983, thanks to a Quality Control sticker on the PCB, signed and dated by ‘Linda’. However, until recently that was about all I could say about this model’s back-story. There is nothing about it on the Connevans website, or indeed anywhere on the web. However, I contacted the company they have been very helpful filling in the blanks. As I suspected this model was intended for domestic applications and was in production from around 1981/2 until 1996 and cost around £45.00. It was designed cover an area of approximately 5 x 5 metres, using twin core bell-wire, either in a single or double loop configuration.

I often suggest that oddball vintage devices like this may one day excite the interest of future gadget collectors and be worth something. Not this time. I'm confident that the LA5 has an almost zero chance of becoming a sought-after collectible and if I were to sell it, I would be lucky to get my money back. Even though it probably still works it is unlikely to perform as well as a more up to date model, and it’s not exactly a conversation piece, or even much use as a doorstop. What it is, though, is unusual, not to say quite rare. It's one of those anonymous behind the scenes items of technology and this is quite possibly its one and only public appearance. Who knows, it might even be the last one left in captivity and thanks to the persistence of Internet archives it will never be completely forgotten, so that has to be worth something?

DUSTY DATA

First seen: 1981

Original Price: £45

Value Today: £1.00 (0618)

Features: T-Coil audio induction loop transmitter, TBA810 power amp & TL071 pre-amp chips, microphone & aux (line) inputs (3.5mm jack), dual loops (2.5 ohm impedance), rotary volume/gain on-off, power on indicator

Power req. 240VAC 50 Hz

Dimensions: 155 x 160 x 80mm

Weight: 1.4kg

Made (assembled) in: England

Hen's Teeth (10 rarest) 9

Gemmy George W. Bush Talking Figure, 2003

‘Rarely is the question asked, is our children learning?’, ‘…a low voter turnout is an indication of fewer people going to the polls’, and not forgetting, ‘…the vast majority of our imports come from outside the country’? And that’s just a small sample of the cringe-worthy gems uttered by this animated George W. Bush figure. Just listening to those classic mis-sayings is funny enough but this superbly detailed talking doll takes it to a whole new level of cruel hilarity with the figure’s head moving from side-to-side and his mouth opening and closing in time perfect time with the words. It will make you laugh!

Although not yet a proper vintage gadget in the dustygizmos tradition, bear with me and take this as a timely heads-up because The George W. Bush Collector’s Edition Animated Figure might be well on its way to becoming one. It first appeared in the early noughties, a year or two into George Dubya’s presidency. Even before he became the leader of the Free World, as Governor Bush, he had form for saying unintentionally funny (and often quite worrying things), though to be fair, over the years a lot of what he is purported to have said was either made up or wrongly attributed to him. This clearly didn’t worry Gemmy Industries, the US company responsible for this doll and a lot of other animated celebrity figures in their Pop Culture Series.

Yes, of course it is very tacky, but it’s really well made tack, from the brilliantly caricatured and made-up giant head to the neat little ‘leather’ jacket and denim jeans. Even the quotes, voiced by a gifted actor, sound just like the real thing. With three AA cells in the compartment on the base, or connected to a mains adaptor, it’s ready to let rip. To get George talking simply press one of the two buttons labelled ‘Funny’ and ‘Inspirational’. Incidentally the latter is neither funny nor particularly inspirational but it was probably put there in an effort to offset complaints from Republican-voting US citizens with low humour thresholds. In any event the properly funny quotes outnumber the other ones by 5 to one, so there’s plenty to listen to.

Inside the head and body there are a pair of actuators, to move the head and mouth. The ‘voice’ comes from small speaker in the base, connected to a PCB with, among other electronic components, a dedicated microchip programmed with the sounds and actuator drivers. Undressing the doll to take the internal photos somehow seemed very wrong as it involved exposing his perky plastic bum to remove the screws holding the body together. Just getting at them proved to be quite a tricky operation as George had been sewn into his clothes, but they were so well made that putting them back on again without damage really wasn’t a problem.

This one was a boot sale find, priced at a haggle-proof 50 pence, probably because the battery cover was missing. This hardly mattered, they stay put without it, and as I later discovered, it was in full working order, needing nothing more than a good dusting and wipe-over with a damp cloth. How it came to be in the wilds of Dorset I will never know but since – as far as I am aware -- they were never officially sold in the UK is was probably brought back as a holiday souvenir

What Happened To It?

Gemmy Industries came into being in 1984, in Dallas Texas and from then until now it has specialised in animated figures, novelty products and character inflatables. They also market an enormous range of peculiarly American items like ‘Halloween Porch Greeters’ and ‘Yard Décor’ plus the kind of completely over the top illuminated Christmas house decorations that can be seen from space. The animated Pop Culture series, of which George W. Bush was just one example, appears to have been manufactured in China. They were in production from 2002 to 2004 and included the likes of Louis Armstrong, Frank Sinatra, Rocky Bilboa and Lucille Ball. Incidentally, several copycat and counterfeit designs appeared when production came to an end and these are sometimes misleadingly attributed to Gemmy. The clever caricatures, sharp one-liners and animation are YouTube gold and it didn’t take long for the short-lived Pop Culture series, to gain a following in the US, and spawn a healthy collectors market plus several websites devoted to the subject.

They are still quite rare in the UK and George W. Bush and his friends make only occasional appearances on ebay but because they are not widely known or appreciated on this side of the pond, prices can be quite modest. Prices on the US ebay site vary enormously but it’s easy to spot the most sought after ones, with mint, boxed Santa-suited Bing Crosbys approaching three-figure sums. George W. Bush clearly isn’t anywhere near as appealing and they can be found for between £10 and £20, but beware of high shipping charges to the UK, which can double or treble the final cost. A short production run, finite supply and iconic characters can be a catalyst for steady price increases. Maybe not so much for George W, but old reliables, like Sinatra, Armstrong, Crosby, Abbot and Costello, James Brown and John Belushi (in full Animal House get-up), will always be in demand and worth grabbing, and if you see one in its original box, at a sensibly low price, there could be money to made selling them back to US collectors…

DUSTY DATA

First seen: 2003

Original Price: $19.99 (around $27 or £20 in 2018 money)

Value Today: £25 (0518)

Features: Moving head and mouth, 20 funny and 5 inspirational ‘quotes’, faux leather jacket, denim jeans check shirt, DC connector

Power req. 3 x 1.5 v AA cells or 4.5v DC adaptor

Dimensions: 330 x 140mm

Weight: 450g

Made (assembled) in: China

Hen's Teeth (10 rarest) 7

Linwood Simple Siren Car Alarm, 1984

Judging by recent media reports car theft has never been easier, thanks to many modern (and usually expensive) cars being fitted with super-secure ‘keyless’ ignition systems… A cynic might mutter something about Murphy’s Law and chickens roosting, though to be fair nicking cars, or ‘Twocking’, (taking without consent – I know all the modern words…), has been with us, probably since before the first Model Ts rolled off Henry Ford’s production line. But for some reason, until comparatively recently, car makers have given it a relatively low priority. I clearly remember the well-worn ignition key for my first car, a scary late 60s Austin 1100, could open and start a surprisingly wide range of vehicles, made by the likes of Ford, British Leyland (as was) and Vauxhall. My guess is the only thing that prevented more widespread theft was that most British cars from that era were unreliable rust-buckets hardly worth the effort of pinching. As recently as the 1980s if you wanted to ensure your car’s security you’d have to have an alarm fitted -- it tended to be an optional extra on new cars – or immobilise it with a Heath Robinson device that fitted over the steering wheel. The other option was to fit an alarm yourself, and the Linwood Simple Siren Car Alarm featured here was one of dozens of DIY systems available at the time.

Back then car self-fit alarms were fairly simple affairs and most, including this one, were triggered by a small drop in the car’s battery voltage. This could be caused by the courtesy light coming on,when a door is opened, or switching on the headlights or sidelights. Other types of intruder sensors were also available, like ‘tremblers’, which responded to movement, ultrasonic motion detectors and concealed pressure switches under the carpets and inside the driver’s seat. A keyswitch located on the outside of the car or, in this case, the driver turning on the ignition disables the alarm. A variable entry delay stops the alarm going off straight away. Typically the alarm box or siren module would be mounted under the bonnet, so an additional switch might be fitted to trigger the alarm if it was opened. Old-school alarms like this one tended to be really loud, and would keep going until the owner turned them off, or the battery ran down. There was a time when they went off all the time, usually around 2am, and the ones that used overly sensitive tremblers could be set off by a light breeze, passing lorries, drunks and scallywags. It has got better, though and nowadays car alarms are supposed to cut-off automatically 20 minutes, in theory at least.

The Linwood Simple Siren, as the name implies, was some distance from the cutting edge of alarm technology, but that also meant that just about anyone handy with a screwdriver could fit it, and at around £20, it was a fraction of the price of a professionally installed system. There seems to be two schools of though about the visibility of car alarms; most are hidden away inside discrete black boxes, indistinguishable from the rest of a car’s electrical gubbins. This one takes the opposite approach, and there would be absolutely no doubt what it was for. This might be a good thing on a car accessory dealer’s shelves, but fairly pointless when it’s under the bonnet, and quite possibly a disadvantage if a car thief is hoping to find the source of the noise and shut it up (a bonnet switch seems to be an optional extra on this model).

The most noticeable feature is the built in siren/sounder, clearly visible through the thin plastic grille. This could be a design flaw as it looks like it could be swiftly silenced by a quick jab with a screwdriver. Incidentally, the sounder is actually a small loudspeaker but with a rigid plastic cone, instead of the more usual paper material. It’s effectively a giant ‘tweeter’, designed to operate most efficiently at higher frequencies. The siren sound is generated by a 741 op-amp chip, configured as an oscillator, and the alarm’s voltage sensing and logic circuitry is based around a pair of 4001 quad NOR gate CMOS chips. These and the handful of ancillary components live on a PCB mounted next to the sounder. Connections to the car’s electrical system consist of 12-volt battery positive and negative ground cables, a connection to the ignition switch and a pair of ‘sensor’ wires, to connect to the driver’s door courtesy light switch. There’s also provision for another external sensor (probably the bonnet switch). Apart from the questionable housing it’s all quite well made and there’s even a waterproof ‘conformal’ coating on the printed circuit board, to protect it from moisture.

I found it in a big box of bits at a car boot sale; I was actually hunting for a 12-volt mains adaptor at the time, which I found, tangled up with the Linwood alarm’s cables. Since it looked like they would take a while to separate I asked how much for both? Fifty pence sounded like a reasonable price and the deal was done. The mains adaptor tuned out to be a dud, so it went into the bin and the alarm went into the might-be-useful-for-bits-one-day box. This was a couple of years ago, and it came to light recently when I was looking for a small speaker. I vaguely remember having this one and it was only when I pulled it apart that I realised it was totally useless for my purpose. It was about to go back in the box when I noticed the date on the PCB (‘pat pending 1984’) and that it was in such good condition. This bought back memories of a review of a kit car alarm and couple of articles that I wrote on car security for a motoring magazine that I was involved with in the early 80s.

It clearly had been installed at some time and fitted with industrial strength metal brackets but it was far too clean to have been in the engine compartment and I suspect it was mounted in the boot. Thanks to the well-labelled PCB I was about to figure out what the five wires emerging from the case were for. It powered up and made a suitably deafening noise, when hooked up to my bench power supply. I was also able to test the voltage sensing function, which operated very effectively when the supply dropped from 13.5 to 13.4 volts.

What Happened To It?

Linwood in Birmingham was the home of Linwood Electronic and for a short while, from the mid 70s to the mid 90s, or thereabouts, they produced a range of car alarms and accessories, like battery chargers, wheel clamps and so on. According to records at companies house they were trading for over 20 years but when the company was formed and dissolved wasn’t shown. They seem to have disappeared without trace, or at least left any sort of footprint on the web, aside from an occasional product turning up on ebay.

Whilst most cars are now sold with some sort of factory-fitted security system as standard, the emphasis has shifted from noisy alarms to ways of preventing would-be thieves gaining access in the first place, and immobilising the vehicle if it is compromised. This has involved all sorts of digital trickery, from basic stuff like remote control and microchipped key fobs to the currently trendy (but seemingly hackable) keyless systems, fingerprint recognition, remote monitoring, GPS tracking and probably coming soon to a car near you (or maybe here already…) voice recognition, retinal scanning and microchip implants for the owner’s body. It’s ironic that the current spate of thefts of cars with keyless systems has prompted experts to advise owners of vulnerable cars to buy a steering wheel lock…

I am not aware of car alarms having any sort of following in the vintage tech collector community, and why would they? Nevertheless it is a mildly interesting subject but I’ll not waste time putting a value on this and other alarms from the same era. The 50 pence I paid for this one (and that faulty mains adaptor) was probably too much, and it certainly has no practical use. I won’t even suggest that you seek out bargains as a potential investment -- that’s not going to happen. It is possible that alarms from a much earlier time – and I’m only guessing that they exist – might be of interest to vintage and veteran car enthusiasts. But dull as they are I would hate to think that the brief history of the aftermarket car alarm, and the Linwood Simple Siren goes completely unrecorded.

DUSTY DATA

First seen: 1984

Original Price: £20?

Value Today: 50 pence (0518)

Features: voltage sensing trigger, internal siren, variable entry delay, auxillary trigger/sensor

Power req. 12 volts DC (car battery)

Dimensions: 162 x 113 x 63mm

Weight: 450g

Made (assembled) in: England

Hen's Teeth (10 rarest) 7

Cosmos Melody Organ, 1979

Firstly an admission. This is not a Cosmos Melody Organ, or rather it is, in all but name. The label on this one says Electronic Organ and it is possible this exact same model appeared in a number of guises. The Cosmos branded variant I found on the web whilst researching this device is one hundred percent identical to it. According to the site it dates from the late 1970s, which sounds about right, but beyond that almost everything, including the identity of the original manufacturer, is still a bit of a mystery.

The verifiable facts include that it very small, just 85 x 62 x 22mm or not much larger than a (largish) box of matches. It has a single-octave keyboard with a full set of sharp and flat keys and this can be switched to a second higher octave by pressing the small blue key on the left hand side of the top panel. Possibly the most interesting feature is the 56 note memory. This is enough to rattle out and replay most ditties, though sadly its titchy memory only extends to repeating notes, not their length or intervals, so recognising them from the recording is a bit hit and miss. You can jazz up your tunes as you play, though, with the yellow button, which adds a weak tremolo effect, and when you get bored with that there are eight programmed melodies, which it plays at random, including such diverse works as ‘Swanee River’ and Beethoven's 'Für Elise'.

All of this virtuosity is down to a single Texas ORG138SP 28-pin microchip, plus small handful of ancillary components. Oddly there are no references that I can find of this component, which may indicate that it had a very short production run. As a matter of interest at around that time chipmakers were busily churning out all sorts of device-on-a-chip designs including, most notably -- to us nerds -- the General Instruments AY38500. This was a classic one chip device and arguably responsible for kick-starting the home video game revolution, bringing the joys of on-screen table tennis and simple shoot-em-up games to the masses.

There’s little to say about the innards. It comprises just two small PCBs, one for the rubber-contact keyboard, mode and on/off switches and the other for the chip and the rest of the components. Musical notes escape from a 20mm piezo sounder and it is powered by a 9-volt PP3 type battery, housed in a compartment on the rear of the case. If you forget to switch it off it reminds you with a beeping alarm sound after a couple of minutes of inactivity.

This one came all the way from South Africa, via my brother Pete, on his annual visit to the UK. He found it on the Bidorbuy online shopping site, a sort of South African ebay, but with a lot less over-priced crap... And that’s about as far as its previous history goes. It has clearly had very little use, being in excellent condition and good working order. My guess it spent most of the last 40 odd years in storage or the back of a drawer. It was also pretty clean inside and out; all it needed was a quick polish of the switch contacts with a fibre brush, to sort out the intermittent function switch. It goes without saying that the organ sound it makes is a tad tinny so it’s musical abilities are somewhat constrained but it’s still a lot of fun to play with, and rendering or recording a recognisable tune can be quite a challenge.

What Happened To It?

Whilst a moulding on the battery compartment of this one clearly states that it was manufactured in Japan, the very few references to its Cosmos twin implies that it is was made Portugal, by Luso Toys. Photos of the Cosmos variant clearly show the keyboard and internals as one hundred percent identical to this one but a photo of the Cosmos back panel bears a Made in Portugal stamp. There are two possibilities for this apparent discrepancy. One, they were both made in Japan but the Luso Toys version was supplied with a custom back panel to imply it was made locally. Two, the Cosmos variant really was made in Portugal by Luso, but under licence from its Japanese manufacturer. Personally I favour the first explanation. Country of origin labelling laws were a lot more relaxed back then and as far as I am aware Portugal in the 70s had no track record of manufacturing electronic devices (though it might well have had the capability to make the plastic case) but as always, if anyone knows different I am happy to set the record straight.

It’s a great little gadget and there’s no doubt that in its heyday it would have been a real crowd pleaser, in the school playground or even down the pub (it didn’t take much to amuse us back then…). For such a small device it packs in a lot of features and if it had been even a little more tuneful it might even have found its way onto a novelty pop record, following in the footsteps of the Casio VL-Tone, Stylophone and even the Texas Speak and Spell. Sadly it has almost vanished into obscurity and the fact that there are so few of them around points to it not being in production for very long, or widely distributed, outside of Japan and Portugal. Electronic organs, even really small and unusually well appointed ones like this have yet to become collectibles but its charm, and rarity – I have yet to see another one in the wild or on ebay -- could change all that. I’m being quite optimistic about its value, £10, say, for a clean unboxed example like this and two or three times as much for a mint one in its original packing. And if anyone can point to it ever having been featured on a record or appeared in any TVs or movies, get your chequebooks out and form an orderly queue.

DUSTY DATA

First Seen: 1997

Orginal Price: £5?

Value Today: £10.00 (0518)

Features: Full-range single-octave keyboard, second octave switch, 56 note memory, 8 pre-programmed melodies, tremolo button, built-in piezo sounder, inactivity/battery-saver alarm

Power req. 1 x 9-volt PP3 battery

Dimensions: 85 x 62 x 22mm

Weight: 52g

Made (assembled) in: Japan

Hen's Teeth (10 rarest) 8

Science Fair 200 in One Electronic Project Lab, 1987

Even though this Science Fair 200 in One Project Lab is more than 30 years old this, or something very much like it, should be issued to every kid of secondary school age. Several generations have grown up without having the faintest idea of what makes their beloved tech tick. Okay, so it’s not essential to know what goes on inside a microchip to use modern widgets, but it seems that far too many people these days cannot even change a light bulb or fit a mains plug, let alone fix simple faults when something goes wrong.

It is true that kids learn how to swipe screens in their cots and perform the limited range of actions allowed by the software on their devices, often with amazing dexterity. In later years some may even acquire a basic understanding of the languages and codes that determine what appears on their screens, but this is far removed from the nuts and bolts of electronic circuitry, where the really clever and important stuff happens.

Kits like this one were common throughout the 60s up until the late 1990s, and then the digital revolution and black box technology effectively sent us back to the Stone Age, as far as understanding how things worked is concerned. Before that youngsters could gain hands-on experience of simple, and sometimes quite sophisticated electronic gadgets. Even if the rudiments of how the individual bits and bobs worked didn’t sink in, they were still getting to handle electronic components, wires and batteries. There was satisfaction in putting something together, especially if it worked, and seeing first-hand what was inside a radio and things that blink and bleep, and in this case, around 200 electronic circuits that are the building blocks of most of today’s electronic gadgets.

To be fair this kit, which first appeared in 1987, took a slightly sanitised approach. The gold standard for user involvement has always been the Philips Electronic Engineer series of kits, launched in the early 1960s. In early versions the components were supplied in their natural wire-ended form; however, constant bending led to rapid failure. Later kits, like this one, attempted to protect the parts by mounting them on a simple ‘breadboard’, with the delicate wires connected to more robust spring terminals. Some even went the whole hog and encased them in small plug-in modules. The Science Fair 200 in One doesn’t go that far; most of the parts are exposed and on show, so you can see, touch and even smell them, and they can withstand a lot of rough treatment.

The projects are a good mixture of practical demo circuits that show how various parts function, to quite ambitious things like digital counters, an AM transmitter and an LED sound level meter. Each project has detailed, yet easy to understand instructions and a section that explains how it works. Circuits are created by linking numbered spring terminals -- connected to each component -- by short lengths of insulated wire. The manual includes circuit diagrams so you can clearly see all of the connections, and easily rectify mistakes, when whatever it is you’re making doesn’t work. The layout is excellent, with the main controls, display and sensor components mounted on the front panel, styled to look like a piece of hi-fi equipment. Components are grouped together on the colour-coded breadboard, making them easy to identify and power comes from a set of 6 AA batteries, which live in a holder on the right side of the back panel. Assembling a project can be quite time-consuming, with some of them requiring up to 100 connections, but what’s the hurry?

The really great thing, though, is being able to tear a circuit down in few seconds and start another one straight away. Even if you’re not electronically minded or even completely disinterested, you can’t help absorb at least something of what’s going on. In decades past humble kits like this often paved the way to electronics as a hobby, a path into higher education or even a well-paid career. The bottom line is that a basic knowledge of electronics and the skills acquired by making things, has always been an invaluable preparation for life in an age where we are so dependant on technology, and all too often flummoxed, when things go wrong.

One of Brighton’s larger car boot sales was the source for this kit. The cardboard box showed signs of light wear but I could hardly believe what was inside. It was in absolutely mint condition. Even the bag containing the wire connectors, earpiece and antenna wire was still sealed. The price negotiation took all of 5 seconds, the stallholder said three quid and I said OK. It was clear that it had never been used and I wasn’t about to defile its originality by using the wire original connectors (carefully removed and re-bagged after photography) but I couldn’t resist trying out a few projects. I used some connecting wire of my own and they all worked flawlessly. Revisiting old novelty circuits, like the ‘Chirping Bird’, ‘Electronic Cat’. ‘Two Tone Siren’, ‘One Transistor Radio’ and the ‘Electronic Organ’ was a real trip down memory lane.

What Happened To It?

Science Fair was one of Radio Shack’s house brands. It was better known in the UK as Tandy from 1973 their busy stores were a familiar feature in many high streets. Sadly the chain lost direction; from the mid 90s Tandy struggled to keep up with the rapid changes in technology and the market and the last shops closed in 2001.

The 2000 in One was one of a dozen or more Electronic Project Kits sold by the company over the years. In the US Radio Shack introduced the first Science Fair Project Lab kits in 1969. Tandy took a while to catch up and in 1974 they featured a handful self assembly kits under the Science Fair name but they were for single devices, like radios, amplifiers, electronic organs and so on. Project Kits didn’t make an appearance until 1980 with the first one featuring 150 circuits. The following year the first version of the 200 In One kit was introduced. This was later revamped and became the one you see here, with the addition of digital logic microchips, silicon transistors and the more up to date front panel presentation.

Electronic project kits, like chemistry sets, never completely disappeared but little by little they became bland and uninteresting. They fell victim to health and safety – even this one has a minimum age recommendation of 10 and stern warnings about sharp pointy bits. Where’s the fun in that? Over the years changes in the school curriculum placed less emphasis on learning about electricity and electronics, and, of course there were the more alluring attractions in the pipeline with shops full of video games, computers and bucket-loads of ready-made electronic devices.

Toys and games, even educational ones have always been collectible, but interest, and therefore value, tends to be dependent on age – pre 1970 is a rough and ready breakpoint. Later items can also be highly sought after but normally it is dependant on some sort of link or association with a movie, TV program or personality. The 200 in One is a little too young to get serious collector’s juices flowing, even so examples in good condition, like this one, regularly sell on ebay for between £20 and £40, less well looked after ones can be found at car boot sales for pennies to a few pounds. They have to be a sound investment; there are enough of them around to be able to make up complete ones from two or three basket cases. Inevitably, as the supply of sensibly priced vintage toys and games dries up the price borderlines will change so be warned; it will be the cost of stuff made in the 80s and 90s -- that you threw away, or passed up at your boot local boot sale -- that will make your eyes water.

DUSTY DATA

First Seen: 1987

Original Price: £39.99

Value Today: £20 (0418)

Features: 200 electronic projects involving 20 resistors, 10 capacitors, 4 transistors, 3 diodes, 7 LEDS, 1 x 7-segment display, moving coil mete5, 2 x transformers, 2 x logic gate microchips, relay, ferrite antenna, CDS photocell, variable capacitor, variable resistor, selector switch, Morse key, speaker

Power req. 6 x 1.5 volt AA cells

Dimensions: 370 x 225 x 70mm

Weight: 770g

Made (assembled) in: China

Hen's Teeth (10 rarest) 6

Benkson 92 Transistor Baby Sitter, 1965

Hats off to all of the pioneering electronic engineers who worked in the late 50s and early 60s. Most of them would have grown up valves, or tubes, as our American cousins like to call them, so making the transition and getting to grips with the new fangled transistors would have involved a major learning curve. Essentially they were starting with a clean slate but they quickly got the hang of the new technology. Their ingenuity and creativity bought about seismic changes and marked the beginning of what was arguably the most exciting period in consumer electronics.

Semiconductors opened up a vast new world of possibilities, however, the first commercially available transistors were comparatively expensive so those engineers, designers and marketing folk came up with all sorts of crafty wheezes to get the new technology into the shops and in front of a (then) largely sceptical public. Take this Benkson 92 Baby Sitter for example. If you're a regular visitor to dustygizmos it might look slightly familiar. That's because the plastic case and simple two-transistor amplifier it uses, turns up in at least three quite different guises. Take a look at the Homer KIT-505 Telephone Amplifier and this Eagle TI 206 2 Station Intercom and spot the similarities.

The Benkson 92 Baby Sitter is arguably the simplest of the lot. It's an ultra basic baby alarm. One box, containing a small 55mm speaker acts as a microphone and this sits next to the sleeping child's cot or crib. It is connected by a long 2-wire cable to the other box, labelled the 'Mother Station'. This houses the aforementioned amplifier, a second speaker, on/off switch and a 9-volt battery. Cries and any other sounds picked up by the remote station are heard though the Mother Station's speaker. And that's pretty much all there is to say about it, except that it shouldn't really exist. This may even be the only one left in captivity, but we'll come to that in a moment.

It caught my eye whilst trawling ebay for unusual intercoms, as you do on cold wet winter evenings, when there's nothing on telly (maybe that's just me...). It looked like a dozen or more models using the same case design but for some reason the lack of buttons, odd-looking box and low price made me take a closer look.

It appeared to be in almost as-new condition, with the original box, instruction leaflet and even a warranty card. Normally that would be enough to get it noticed and attract a bid or two, but the description made it clear that it wasn't an intercom and the cable was missing. In the end I was the only bidder and it became mine for only £4.00. The description was accurate; it even came with an unopened bag of cable clips and it was obvious that it had been little used, if at all. Plugging in a cable from another vintage intercom that I had to hand showed it to be in good working order with audible, if not especially clear and loud sounds from the Mother Station.

What Happened To It?

So far so ordinary, but as I suggested earlier there is a bit more to it than meets the eye. It really is ninety-five percent one of those common or garden 2-station Intercoms. The only missing parts are a couple of push buttons and a volume control, components that would have cost the manufacturers just a few pennies. The necessary cutouts are even moulded into the case (but hidden by the front panel labels). Presumably some bright spark decided that there was this huge gap in the market for a dedicated baby alarm. All they had to do was slap a cutesy picture of a baby on the box and desperate mums and dads would be snatching them off the shelves.

Unfortunately, it appears that their market research failed to take into account that there were already countless cheap 2-station intercoms in the shops, also being touted as baby alarms. To make matters worse in the UK it was priced at least pound or so more than those near identical intercoms. Considering that I have never seen another Benkson 92, or anything like it, on ebay or the wider web, either before or since, suggests that it probably didn't sell very well, if at all. I seriously doubt this is the only one in existence, but there can't be many of them around, and in this sort of condition, in which case my estimate of its current value is way, way too low...

DUSTY DATA

First seen: 1965 (Instructions)

Original Price: £4 9s 6d (£2.47)

Value Today: £5.00 (0118)

Features: 2-transistor amplifier, rotary on/off switch, 2 x 55mm (2.25in) speakers, 66 metres connecting cable, 2.5mm minijack connectors

Power req. 1 x 9v PP3 battery

Dimensions: 104 x 78 x 40mm

Weight: 127/98g (master/sub)

Made (assembled) in: 'Foreign' (probably Hong Kong)

Hen's Teeth (10 rarest) 8

Military Shell Headset 5965-99-100, 1970?

Here’s two quick ways to give yourself a headache. Method one is to research the origins of a vintage military headset using just serial numbers and vague descriptive terms. Method two is to try wearing said military headset for more than five minutes. The item in question is the 5965-99-100 ‘Shell’ headset and apart from not being very comfortable, it has proved nigh on impossible to say with any certainty when they came into service, or when they were eventually de-commissioned.

They seem to have had a long and varied career in the armed forces, if the descriptions on ebay and the wider web are anything to go by. Apparently they’re to be found on the heads of tank crews, supplied to aircrew and used with field radios, which may all be true but the minimal sound insulation provided by the ear cups would probably make them more of a hindrance than a help in very noisy environments. In common with most other military headsets they differ from civvy headphones in one important respect; instead of a comfy cushioned headband there’s a thin strap that goes over the top of the head – made of leather in this case -- and a stiff wire connecting brace or frame that goes around the back of the head. This arrangement allows the headset to be worn with a helmet, and at the same time keep them firmly in place, whatever the wearer is up to, or being subjected to, which could be almost anything, from nearby explosions to teeth-rattling vibrations in the back of an armoured personnel carrier.

The three vital components in the headset are inside the rubber earcups and boom-mounted microphone, and they are all the same. It uses identical low-impedance (40 ohm) magnetic transducers made by Racal, and they are not dissimilar to the microphone and earpiece modules found in telephone handsets. The fact that a common part is used for both applications clearly helps keep the cost down and makes them easier to maintain. Construction is in line with most other types of military hardware; it is simple, there are no frills and it is tough and can withstand a lot of rough treatment. The rubber earcups or ‘shells’ are supposed to be a close fit around the ear, to give some sound insulation and cushioning, though with the usual one-size-fits-all approach, and little or no adjustment, it’s suits those lucky enough to have the standard military-issue head size. The mike boom has limited fore and movement -- by slackening off a knurled knob -- the deliberately limited sensitivity of the microphone means that it should be positioned as close to the user’s mouth as possible. It can also be swung up or down, out of the way, when not in use. This variant is fitted with a Swiss-made 3-pin Lemo FGG 1B connector. It has a push-pull self-latching system for a positive lock into whatever piece of equipment it is being used with. As a matter of interest this is a high quality, ruggedised design, perfect for military applications and alarmingly expensive – these days plugs of this type and quality sell for the thick end of £20.00.

As is often the case this one was found in a box of junk at a car boot sale, tangled up the cables of several with quite nasty looking modern headphones. The stallholder wanted to sell them as a job lot for a fiver but seemed happy enough to accept my offer of £1.00 for just this one, provided I disentangled it. Even at that stage, fresh from a wet muddy field – ironically, one of its natural habitats -- it appeared to be in good shape. The light film of grime cleaned off easily and the rubber parts were treated to a generous application of silicone spray, which should help restore and preserve the rubber’s flexibility for a good few years. The leather strap was in a similar state with almost no signs of wear or aging. Both the earphones and microphone modules were in good working order but it isn’t going to be re-purposed anytime soon. Sound quality is as it should be, fine for speech in a noisy environment but it doesn’t even get close to Lo-Fi, let alone Hi-Fi, but in any case the modules would be a poor match for most modern devices.

What Happened To It?

Based on date stamps and sketchy and conflicting information on the web the in-service life for this design could extend from the early 1940s to the mid 70s. For what it is worth my guess is this particular headset was probably made in the 1970s. The reasons for that are the use of relatively modern plastic-insulated screened cables, which all look original, the Lemo connector (it is based on a design patented in 1957), and the condition of the rubber parts. Even with very careful storage rubber naturally deteriorates but this one almost looks like it was made yesterday. I cannot be certain of the manufacturer, either, though there is a good chance it was made by Racal who have a very long history in military communications. It’s not particularly rare, though examples in this sort of condition are few and far between. The rubber parts of most of the ones I’ve seen on ebay seem to be in an advanced state of decay. Although they probably cost the Ministry of Defence a tidy sum back in the day they are never going to be worth much more than the £5 to £20 they typically sell for ebay as converting them to be anything other than a basic military headset would be a costly and probably fruitless exercise.

DUSTY DATA

First seen: 1943?

Original Price: £?? (1117)

Value Today: £15

Features: twin mono-wired low-impedance headphones (40 ohm), low impedance magnetic microphone (40 ohm), leather headband, wire neck band, boom mounted microphone, Lemo FGG 1B 3-pin connector

Power req. n/a

Dimensions: earcups: 95 x 70mm), mic: 50 x 30mm (all approximate)

Weight: 400g

Made (assembled) in: UK

Hen's Teeth (10 rarest) 5

Beseler PM2 Color Analyzer, 1985

This imposing box of tricks was once a must-have tool for anyone involved in the dark art (quite literally) of processing colour photographs. The Beseler P2 is a Color (or colour – depending which side of the Atlantic you happen to be on) analyzer (analyser…). It is used to measure the colour and brightness values of a negative, to determine the optimum grade of photographic paper, filter values, exposure times and so on, to get the best quality print. In fact it is an analogue computer – no digital nonsense here – with what amounts to a simple ‘memory bank’, for storing a range of settings..

The key component is the small black box on the end of a cable; this contains a highly sensitive light detection device that can be set to only respond to a single colour (yellow, cyan or magenta), or white light, using a set of switchable filters. It is used in a darkroom and the probe is placed on the bed of a photographic enlarger. The film negative to be analysed is projected on to the white area on the top of the probe. Measurements are taken by twiddling the various knobs and recording the values indicated by the knob pointers and readings on the meter. Normally I would go into a bit more detail about how it is used but even after reading through the manual (link below) several times, I am no wiser. What little I used to know about processing photographic film – largely unsuccessful attempts at developing and printing black and white photos many decades ago – didn’t help to make things any clearer. Colour print processing appears to be a very complicated business and life is too short to get up to speed on what is, sadly, a dying art…

So how did it end up on dustygizmos? Simple, all those knobs, the big meter and unusually clean condition immediately caught my eye at an antiques fair in Somerset. The £10 price tag persuaded me that it was worth a second look. It was obvious that it had been very well looked after, it even had its original dust cover, but it still seemed too cheap to be true. However, it turned out that neither I, the stallholder and the few others who had spotted it had any real idea of what it was, but he must have sensed my interest, and said I could have it for a fiver, to save him lugging it back home. It was an offer I definitely couldn’t refuse. As I later found out it was even more of a bargain than I first thought. It turns out I had missed the star feature; the Beseler P2 and many other similar instruments of the same vintage is equipped with a high-quality photomultiplier tubes -- the light sensitive component in the probe – and on their own can sell for the thick end of £100.

Please skip this next bit if you’re already bored with all this talk of photomultiplier tubes. They have numerous applications and one of them is of particular interest to me. They are the core components in an advanced type of radioactivity detector, called a scintillation probe. The tube is coupled to a special type of crystal that emits a brief, and very dim flash of light in the presence of radioactive particles. The tube’s job is to amplify the flashes many thousands of times so they can be measured. The interesting bit is that unlike common or garden Geiger Muller detectors, which emit a simple pulse when they detect radiation, the flash from a scintillator crystal varies in intensity according to the type of material producing the radioactivity. When the pulses are processed by a device called spectrum analyser it is possible to accurately identify the radioactive isotope(s) involved. This area of nuclear physics sounds a bit nerdy and specialist. In fact it’s actually quite exciting and well within the scope of the average hobbyist. Apart from the probe all you need is a simple electronic power supply, a PC and some free software to analyse and identify the signals coming from the probe. We’ve drifted off-topic, but the point is there is currently a good supply of redundant colour analysers on the market with photomultiplier tubes, often at bargain basement prices.

Welcome back and on with the business in hand. As I said earlier this one appeared to be in very good condition and following a wipe over it looked almost as good as new. In retrospect this isn’t too surprising; in the normal course of events they don’t get a lot of use and tend to be well looked after by their naturally careful owners, not that there’s much to wear out. It was £5.00 well spent and as far as I can determine the photomultiplier tube and the rest of the circuitry is in good working order. Exposing the tube to varying levels of light produced large movements on the meter and, as did moving the knobs. Hardly a scientific test I know, but it bodes well for any future experiments involving the photomultiplier tube. Before we move on a quick mention for the ‘memory bank’ function. This is a bit weird but I seem to recall similar contrivances back in the pre-digital days when a lot of people were experimenting with analogue computers. Essentially it’s the group of six potentiometers in the top right hand corner of the front panel, and you may be able to see from the photo that they have a hinged Perspex cover. That’s pretty much all there is to it, the chosen adjustments are stored on the pots, then ‘memorised’ by preventing them from further adjustment by lowering the flap.

What Happened To It?

Now based in Pennsylvania the Charles Beseler Company dates back to 1869 and has been involved in the photography and optics business for the better part of 150 years. It moved into the amateur and professional markets in the early 1950s, producing a very successful range of darkroom enlargers, and became a leading supplier of darkroom equipment to schools and colleges. More recently it has become major player in shrink-wrapping and packaging.

As a matter of interest, although the Beseler P2 was manufactured in the US a label on the back panel says it was made under licence from a UK company called Melico

Digital electronics and solid-state image sensors put paid to big old beasts like this. There is still a market for colour analysers but modern versions are smaller than the probe on the P2, much cheaper and a lot more sophisticated. I haven’t been able to find an exact price for this model, but the P2L, a basic variant of the P2, was selling for around £300 in the US in the mid 1980s, so I’m guessing this better specified model sold for between £400 and £500. Today it is practically worthless as a darkroom tool but it does have some value. No doubt there are a few photographic equipment collectors out there who would be pleased to give it house room, though it will be a few years before it achieves vintage status. There’s probably a few die-hards still using analogue kit like this, but for experimenters and hobbyists it’s the photomultiplier tube, high quality analogue meter and the rest of the components, which make it interesting, and well worth the £10 to £30 devices like this can sell for on ebay.

DUSTY DATA (manual)

First seen: 1985?

Original Price: £450

Value Today: £20 (1117)

Features: Photographic colour analyser, photomultiplier probe with 4 switchable filters/channels, centre-zero moving coil null/filtration/time scale, analogue value program ‘storage bank’, Spot/Integration/Analyse program functions,

Power req. 240 volts AC

Dimensions: 278 x 270 x 265 mm

Weight: 6kg

Made (assembled) in: USA

Hen's Teeth (10 rarest): 8

Receiving Set Infra Red Binoculars No.1 Mk 1 Cased 6650-99-960-7616,1970

As well as having the longest name of anything featured in dustygizmos to date, I have to report that it is one of only a small handful of gadgets featured so far that does not work. The reasons for that will become apparent shortly.

The British Army Receiving Set, Infra-red Binocular, No1 Mk1, Cased 6650-99-960-7616, otherwise known as the ‘Common-User Binoculars’ are not, as you might suppose, vintage night vision goggles. In pitch-dark conditions they would of very little use. In order to see anything through them the scene has to be lit by infra-red (IR) light, which is (or should be) invisible to the naked eye. Inside each of the binocular tubes there is a small device called an image converter, which as the name suggests, converts infra-red light into visible light. Although fully self-contained, relatively light and portable, these helmet-worn goggles were not widely issued to ground troops. The problem was that requirement for a powerful IR light, however, they did prove useful for drivers of tanks, armoured vehicles, troop carriers and so on, which could be fitted with IR floodlights, and in theory allow them to move around safely at night.

It’s a clever design that owes much to an earlier monocular IR viewer called the Type K or ‘Tabby’, which was developed for the British army in the 1940s. These Common User Binoculars, which date from the late 1960s, consists of two separate units, coupled together by cables inside a canvas-covered strap. The idea is they clip onto a steel helmet (Mk III or ‘Turtle type); this arrangement balances the weight of the two modules, and does away with the need for any trailing wires. The binocular assembly at the front houses the two converter tubes. They have a magnification factor of x1 (i.e. no magnification) and are mounted on a spring-loaded swing arm, so it can be quickly flipped up out of the way. The rear module is a high voltage power supply running on a single 1.5 volt C cell. This uses a simple one-transistor oscillator driving a transformer and step-up coil to generate around 12,000 volts, which is needed to power the converter tubes.

Alas the CV6099/VX8515 tubes are the only components missing from this otherwise complete outfit. Although they are quite rare I have come across several sites selling them on the web, as well as the occasional ebay listing. So far I have resisted the temptation as they have either been horrifically expensive, or the seller has been unable, or refuses, to say if they work or not (and they still wants too much money for them…). I have not given up, though, and if and when I am able to get my hands on a pair (or even one) I will add a postscript. If I ever do the good news is that they are really easy to fit, only taking a minute or so; simply unscrew each eyepiece, pop in a tube and screw the eyepiece back on.

Overall the condition of this outfit is very good and it appears to have had little actual use. In fact the only part that shown any signs of wear is the carry case, which has clearly had a tough life and done its job well. I found it at small antique market in Surrey some time ago and because the missing tubes and tatty-looking case, the seller was only asking only £10 for it. The power unit looked very clean, inside and out, and produced a hopeful sounding whine when a battery (a single 1.5 volt C cell) was fitted. The output peaked at around 11.5kV, close enough to the rated supply to suggest that all was well and it should function with a couple of converter tubes installed.

What Happened To It?

Night vision technology goes back a surprisingly long way and experimental systems were being developed in the late 1920s. So-called ‘active’ or Generation 0 equipment, like the bins shown here, which rely on an external source of IR information first appeared in the late 1930s. The Germany army is credited with being the first to put this kind of equipment into service in 1939.

British Army Common Use Binoculars appear to have been in use for around 20 years, until well into the 1980s, long after the development of ‘passive’ or Generation 1 night vision devices. These rely on image intensifier tubes to amplify ambient light, from the moon and stars etc., by a factor of 1000x or more. These were first deployed by the Americans during the Vietnam War. The changeover from active to passive systems looks like a no-brainer. However, it seems to have taken rather a long time, given the fact that they must have been a real liability on the battlefield. Apart from anything else the necessary IR illuminator would be clearly visible, and presumably an easy target, for an enemy equipped with similar equipment.

Even in good working condition I doubt that a pair of Common Use Binoculars have much practical use these days. They’re virtually unwearable without a suitable tin helmet and laying on a source of IR light could be a problem. Nevertheless, vintage military equipment can be very collectible and good working examples of this model appear on ebay every so often, in some cases selling for several hundred pounds. This one was undoubtedly a lucky find and a real bargain. With a pair of working tubes and some clean up work on the case, it might well achieve a three-figure sum. The only problem is that replacing the tubes at current market prices would virtually wipe out any profit. If you are after one in working order be prepared to pay handsomely for the privilege, or be patient, seek a fixer-upper and factor in the cost of replacement converter tubes.

DUSTY DATA

First seen: 1968?

Original Price: £?

Value Today: £30 (1017)

Features: IR sensitive night vision binoculars, fixed focus x1 magnification, 2 x CV6099 image converter tubes, 1.3kV power supply.

Power req. 1 x 1.5 volt C cell

Dimensions: 450 x 140 x 130mm

Weight: 1.4kg

Made (assembled) in: UK

Hen's Teeth (10 rarest): 8

C-Scope ProMet II Metal Detector, 1986

You have to be a hardcore glass-half-full optimist to be a metal detectorist. It’s not that you won’t find anything, you almost certainly will, probably within minutes of switching a metal detector on for the first time. The trouble is ninety-nine percent of what you’ll find is likely to be rubbish. On the other hand there’s that magic one percent possibility of unearthing something interesting, and occasionally even valuable, and that’s what makes it such a popular hobby. As it happens there are ways to improve the odds and that’s to invest in some decent kit, spend time learning how to use it, and carefully pick the places where you do your detectoring – and yes, that is a real word…

Although this C-Scope ProMet II is more than 30 years old, it is the sort of metal detector that can help limit the number of bottle caps, rusty nails, bits of tin foil and so on you’ll dig up and, with practice, help tell the difference between a gold ring and an aluminium ring-pull. It’s a ‘discriminator’ several steps up from basic detectors and for good measure it can also compensate for differing ground conditions. This can have a big effect on a detector’s sensitivity and performance. For example, a piece of metal buried in a heavy clay soil can give an entirely different reading, or no reading at all, when the same object is at the same depth on a sandy, saltwater-soaked beach.

In comparison with most of today’s fancy digital detectors the ProMet II is relatively crude, being mainly analogue in nature. That’s not necessarily a disadvantage; manual controls give the user more flexibility, compared with fancy pre-programmed and automatic functions. There is a downside, though, and that’s all those knobs and buttons, and learning what they do, and the time spent twiddling them to get the best results, or rather, to stop the speaker screaming whilst it is being set up, can be a challenge. It does have a couple of automated functions but when it has been correctly adjusted it is actually very easy to use.

Once the telescopic stem for the search head has been extended and tightened the first job is to set the large Ground Exclude switch on the main unit. This has broad settings for Beach (dry sandy or saltwater) or Inland (normal or mineralised). The tricky part concerns balancing the settings on the three smaller knobs. They all interact with one another and getting it just right is as much an art as a science. From left to right they are Ground Exclude fine tune, Tuning and Sensitivity.

Tuning is set by holding down the Status/Tune button on the Meter stalk and turning the Tuning knob until the howl from the speaker dies down and the meter comes close to the centre position. If you are in a hurry there’s an Auto option that gets it more or less right, though sensitivity may not be as good as doing it manually. The Sensitivity control is an aid to discriminating between wanted and unwanted metal, and to some extent, the depth at which objects are detectable.

The controls on the meter stalk are a little easier to deal with; they’re concerned with automatic adjustment of Ground Exclude and Discrimination and switching the audio between a straightforward tone, and a variable tone that rises and falls in pitch as the search head passes over a metal object. With practice this can also help determine an object’s size, depth and even what it is made of.

The meter gives just a relative indication of signal strength. In other words it rises and falls with the tone from the speaker; it looks quite important but in practice it is of limited use. After a while you tend to ignore it and concentrate more on the sound, which can also be piped through a set of headphones – there’s a standard Jack socket on the front of the main unit. Power is supplied by two battery boxes, housed in a compartment accessible from the underside. They’re filled with 12 AA cells, which sounds a lot but they last a good long time and the weight, which is towards the rear of the main unit, helps with the balance.

Build quality is generally very good and it appears to be well protected against the elements. The only minor quibble concerns the size and shape. Even with the stem fully collapsed it’s still quite a lump and not something you can easily carry or transport without a car. This ProMet II came from boot sale in Surrey. It was in a fairly grubby state but it looked intact. There was no corrosion in the battery compartment so the £7.50 I ended up paying for it (haggled down from £10) looked like a fair deal, even if it was going to need attention.

It turned out to be in good working order and just needed a very thorough clean up. It had definitely seen a lot of service in muddy fields, some of them freshly fertilised, judging by the smell… With a full set of batteries on board it let out a loud howl, which just wouldn’t go away until I managed to track down a copy of the instructions on the C-Scope website. With its help I managed to sort out the controls and kill the noise, which only returns when the search head passes over some metal. Five minutes later, on a test run in my back garden I located the sunken piece of pipe for a long forgotten rotary clothes dryer, a Russian military coat or hat badge – I have no idea where that came from – two rusty bottle caps for Irn Bru (definitely not mine…), and some fragments of cast metal that I suspect is WW II bomb shrapnel. These items produced a very clear response but in the first half hour there were dozens of other less well-defined hits. With time, and a lot of holes in the lawn, I reckon that I could learn to determine if they are worth digging up. All that remains now is to give it a proper field test, as it were.

What Happened To It?

C-Scope, based in Ashford in Kent, has been in the metal detector business for more than 40 years and in addition to manufacturing an extensive range of hobbyist products, like the ProMet II - all designed and built in the UK -- they also make specialist instruments for tracing utility pipework and cables, and hand-held 'friskers' for security applications.

As far as I am aware metal detector collectors are few and far between, though there is a healthy market in vintage military instruments, such as WWII mine detectors. The earliest consumer models began to appear in the early 1960s. This was largely thanks to the development of the transistor, which made simple metal detectors light and affordable. Those very early examples stand a fairly good chance of eventually becoming collectibles but the value of later models, like this one, lie in them still being useable. ProMet Ils turn up on ebay from time to time and they can fetch anywhere between £30 and £80, depending on condition, so this one was a really good buy. Had there been a fault in the custom-made search head or the electronics it might have been a very different story. A fair number of the parts are no longer made and could be difficult to source, so unless you can see one working, or it's ridiculously cheap, buying one on spec could be a bit of a gamble; being an optimist really does go with the territory...

DUSTY DATA (Manual)

First seen: 1985-ish

Original Price: £50.00?

Value Today: £30.00 (0717)

Features: Programmed/Manual Ground Exclude (Inland/Beach - saltwater/mineralised) Audio or Meter Discrimination, variable sensitivity, manual/auto tuning, waterproof search head, 3-section telescopic stem, built-in speaker, headphone (std Jack) & charge sockets (3.5mm Jack)

Power req. 12 x 1.5 volt AA cells

Dimensions: Main unit: 450 x 120 x 250mm, Search Head: 205 x 30, Telescopic Stem: 280mm (collapsed), 750mm (fully extended)

Weight: 2.9kg

Made (assembled) in: England

Hen's Teeth (10 rarest): 6

GEC C11B2 Electricity Meter, 1983

Technically this GEC C11B2 electricity meter is stolen property though it’s doubtful the rightful owners want it back. They never bothered to recover it, and since they are in South Africa, and the meter now lives in the UK, it is going will cost them a very pretty penny to come and collect it. More on its epic journey later on.

At first glance electricity meters like this one appear to be relatively uninteresting. To be brutally honest they don’t get much more exciting on the second and third glances… In part that’s because they are such familiar objects, though older electromechanical models like this one are disappearing fast. They also tend spend their lives in cupboards and out of sight. Even when you do see or think about them, it’s only briefly, and usually with a degree of annoyance when you recall your last electricity bill. Whilst it is true that, on the whole, electricity meters are only marginally more fascinating than drying paint, you might be surprised at watts going on inside (old electrician joke…) and answer the age old question about how the disc spins?

To fully appreciate how clever it is, it helps to have peek inside the box, though if the mention of electrical jiggery-pokery makes you glaze over, feel free to skip the next couple of paragraphs. The GEC C112B is typical of most electromechanical meters and its job is to measure and record electricity consumption over time, in thousands of watts (kilowatts) per hour. Basically it works using just two coils. These generate magnetic fields that indirectly turn the spinning disc, which is connected by gears to a simple mechanical counter. And that’s all there is to it; well the easy bit at least…

The first coil is just a couple of turns of really thick cable and this carries the Live mains feed, from the electricity company’s fuse box to the fuse box feeding the light switches and wall sockets in your home. The coil generates a small magnetic field which is proportional to the current flowing through it, and this varies according to the load, or how many appliances you are using. The second coil, which sits on top of the first one is larger and has many thousands of turns of much finer wire. It is wired across the Live and Neutral connections of the incoming supply and this also produces a magnetic field, this time proportional to the voltage of the mains supply. You may be interested to know that both coils consume small amounts of power. It’s around 2 watts apiece but you only get charged for the power used by the current coil, and only when you are consuming electricity, which may or may not bump up your bill, albeit by only a tiny amount. We’re on the home stretch now and the magnetic fields from the two coils are arranged so they are at right angles to one another. This induces eddy currents in the metal disc, which in turn generates its own magnetic field that opposes the fields from the two coils, forcing it to turn. In short, the more electricity you use, the faster the disc spins and the quicker the numbers on the counter (and your bill) racks up.

As an aside it’s worth mentioning that some old style meters, like the C112B, can be persuaded to run slower than they should or even backwards, making it appear that the householder is actually generating electricity and the supply company should be paying them! This really does happen. In the early days of solar power the outflow of electricity from the panels back into the grid would cause the meter to go slow or in reverse. It was also found that some types of electronic devices with exotic power supplies could also unwittingly affect the operation of old meters. However, by far the biggest cause of a slow down or reverse rotation was illicit fiddling by the user. This included physically modifying the meter or its connections, placing powerful magnets close to the meter and so-called ‘black boxes’ connected in line with the mains supply. These use electronic circuits to meddle with the phasing of the supply. Needless to say all such techniques are illegal and well known to supply companies and meter manufacturers who, by the mid 1980s were fitting anti-reverse mechanisms and meter readers were trained to be on the lookout for tampering. Nowadays computerised billing flags up suspicious activity and in some cases the evidence is tragically obvious, like the tamperer’s dead body, or an unexplained electrical fire. Times have changed and modern electronic meters are now immune to most common forms of tinkering and interference, but that doesn't stop people trying...

The technology used in electromechanical electricity meters dates back more than 100 years and along the way there have been many improvements, culminating in the C112. It was introduced in the mid 1970s, and it -- and later variants -- was widely reckoned to be one of the best designs ever. It’s not difficult to see why it’s been so popular (with supply companies and electricians at any rate). It is designed to work safely and reliably 24/7, for decades if necessary, and the fact that millions of them were made, and by the time they were replaced or retired most of them were still working, says everything you need to know about how well they were made. To be fair there’s not a lot to go wrong but you only have to look at the solid construction and the materials used to appreciate the quality. There are a few adjustments inside the unit, mostly to do with initial calibration, but once it has been installed it would be expected to work continuously with any further attention almost indefinitely or until it is replaced. The transparent case cover is made of a super-tough plastic and fitted with a tamper-evident wire seal. The rear part of the case is made of an equally strong thermo-setting plastic; it provides both insulation and a fair amount of protection against physical abuse from irate consumers.

And so to this meter’s back-story. It was kindly donated to dustygizmos by my elder brother Pete, who lives mostly in South Africa. It was left behind following a meter upgrade in his home and since the engineers left it behind, it was destined for the skip. Then he thought of me and ask if I wanted it. I accepted the offer, as I had never opened one up and was mildly curious about what was going on inside. He bought it with him on his most recent annual summer visit to the UK and I still cannot work out how it got here. This is a large, heavy, unusual, and I would guess, very suspicious-looking deviceyet it managed to pass unhindered through Customs inspections at some of the world’s most notoriously twitchy airports. Maybe old electricity meters are a common sight on baggage X-Ray machine monitors, or perhaps the operatives simply weren’t paying attention? In my experience Customs inspectors have a sixth sense for detecting and confiscating perfectly innocent bottles of water, tiny screwdrivers (for tightening spectacle screws) and small Swiss Army Knives in my luggage…

What Happened To It?

The General Electric Company or GEC was founded in London 1866 by two German-Jewish immigrants Gustav Binswagner and his friend Hugo Hurst. They started out as electrical component suppliers and rapidly moved into manufacturing, opening a small factory in Salford, making switches, electric bells and telephones. Rapid expansion followed and by the beginning of the First World War it had become an important player in the fast growing electrical industry, as well as making numerous products for the military. It was at or around this time that several overseas divisions were set up, including the one in South Africa, where the C11B2 featured here was made. GEC continued to go from strength to strength and throughout the Second World War and the years that followed it opened multiple factories and made huge investments in large scale engineering, nuclear power, defence equipment and acquiring other companies. The company’s fortunes peaked in the mid 1980s triggering a series of mergers and acquisitions. By the late 1990s things started to go downhill. The company drifted into debt and after a long drawn out series of increasingly complicated mergers, sales and joint ventures; in 2006 what remained of the once mighty multi-national was voluntarily liquidated.

I am in no doubt that there are some serious collectors of vintage electricity meters out there, and I’m equally certain they pay handsomely for pre WW II models. The trouble with later types, like the C11B2, and others made after ther sixties, is that there are so many of them, and not just in this country. Millions of them must have been made and a fair number of the ones retired from service have been recycled. You can buy fully refurbished ones online for as little as £10, and that is unlikely to change in the foreseeable.

That sounds like a rather bleak outlook, but hunting around the web for information I stumbled across a number of oddballs converting old electricity meters – especially round ones -- into ornaments and Steampunk inspired table lamps. You’ll even find instructional videos on YouTube (requiring varying degrees of skill and attention to safety – be warned…). That’s my own humble effort in the photo. It doesn’t make them any more valuable or collectible but it could turn out to be a useful second life for a familiar object that is fast disappearing from our homes. If it continues at the current rate they will vanish entirely within the next decade so this a perfect time to get in on the ground floor. Start acquiring stocks of old meters now and hone your table-lamp building skills for the day – and mark my words, it will come – when they become the height of retro-chic and sell in trendy tat shops for hundreds of pounds.

DUSTY DATA

First seen: 1975

Original Price: £?

Value Today: £5.00 (0617)

Features: Single phase kWh meter, dual coil operation, 6-digit mechanical counter/register, magnetic eddy current brake,

Power req. AC mains line powered

Dimensions: 175 x 136 x 112mm

Weight: 1.8kg

Made (assembled) in: South Africa

Hen's Teeth (10 rarest): 4

S.G. Brown Type F Stick Earphone, 1925

Most of the gadgets featured in dustygizmos date from the last half of the twentieth century but every so often something so strange comes along, that an exception has to be made. This particular antique oddity is an S. G. Brown Stick Earphone, made in the early to mid 1920s. It is, quite literally, an earphone on a stick. To be precise it is a Type F earphone, which was more usually found in headphones of the time, for listening to early valve radios and crystal sets.

So why is there only one of them, and what’s the stick all about? Quite simply it was designed for ladies, and the partially deaf. The idea was that ladies could listen to a radio without the inconvenience and inelegance of donning headphones, and avoid mussing up their carefully coiffured hair. Stick earphones like this one were also installed in churches, theatres and so on for the benefit of those with hearing difficulties, or seated in the cheap seats. It’s difficult to say which of those applications this one was intended for but the presence of a rotary volume control at the base of the stick suggests that may have been more of a luxury product, for personal use, rather than something used by common folk in public buildings.

One thing is certain, though, this one wouldn’t have been used with a crystal radio. The impedance (its internal resistance) is simply too low. Type F earphones were made in a range of impedances, this one measures around 50 ohms, and is designed for use with valve amplifiers, whereas the impedance of crystal radio headphones is much higher, typically between 1000 and 2000 ohms, and since the signal is so weak there would be no need for a volume control.

Whatever it’s origins there is no denying that it is very well made. Good quality Bakelite (an early thermo-setting plastic) mouldings are used for the earphone casing, the stick, volume control housing and knob, with chromed and plated metal parts and a surprisingly strong metre-long cotton covered cable, terminated in a two-pin Bakelite plug. Both are original and in excellent condition. Incidentally, the volume control on the end of the stick is compact 50-ohm wire wound potentiometer.

There’s not much to say about operation and ease of use, except that it is very light and manoeuvrable, and surprisingly loud, so the volume control is more than a fancy add-on. The earphone is a magnetic type and originally it would have had a ‘Stalloy’ diaphragm. This is the thin metal disc that is mounted very close to the magnet’s poles. Stalloy is the trade name for an alloy of aluminium, iron and silicon, which has the useful property of being attracted to an electro magnet, but not becoming magnetised, so in theory the performance or volume won’t deteriorate. If and when it does the trick was to flip the disc over, which would neutralise any residual magnetism. Diaphragms often got damp and rusty and the one in this stick earphone looks like a compatible replacement. It was manufactured by Richard Thomas and Baldwins and made from a material called Ferrosil, which sounds a lot like an alloy of iron and silicon.

This earphone came from a car boot sale in mid Sussex and at first I thought it was a microphone. So did the stallholder who confidently dated it as an early sixties model and claimed to have tested it, which I found somewhat doubtful. Since he was only asking £5.00 for it, it looked like a worthwhile a punt and he accepted my offer of £3.00 owing to a very small crack in the neck of the stick. This was easily repaired and now you would be hard pressed to spot it without a magnifying glass. Following a thorough clean up it’s as close to mint as its possible to get on something that getting on for a hundred years old. The stallholder was right about its condition, though, and it works really well.

What Happened To It?

Sidney George Brown set up the company bearing his name in 1903. He was an engineer by trade and started out making parts and accessories for early radios, including headphones. The company diversified into scientific instruments and most notably a gyroscopic compass, which gained the company lucrative military contracts. Eventually relations between the S.G. Brown and the Ministry of Defence soured and in the years following the Second World War divisions were sold off and what remained was bought and sold a number of times until the brand eventually disappeared after being acquired by the military contractor Vosper Thorneycroft.

Needless to say the market for stick earphones was quite limited, and short-lived. My guess is it fizzled out by the 1940s, though it’s hard to be sure as this is not a widely researched subject. Ironically a quick search on ebay and Amazon brings up countless modern earphones designed for 'ladies', though they tend to have more to do with girly colours and cute animal shapes, rather than protecting hairdos…

What you will often find on ebay, though is one or two vintage stick earphones like this one and at a very rough guess there were at least three or four manufacturers. Prices are disappointingly low and rarely top more than £20, and that’s for ones in good condition. The lack of information on the web suggests stick headphones are an unexplored backwater and therefore ripe for collectors. I would also bet a pound to a penny that one of these would get you a spot on TV if you showed up with one at the Antiques Roadshow, but it won’t make your fortune. As always, though, don’t let that put you off snagging one if the price is right.

DUSTY DATA

First seen: 1925

Original Price: £?

Value Today: £15.00 (0617)

Features: Low impedance magnetic earphone with Stalloy (or Ferosil) diaphragm, variable volume, cloth covered cable, 2-pin connector socket.

Power req. n/a

Dimensions: 325 x 62 x 28mm

Weight: 200g

Made (assembled) in: Watford, England

Hen's Teeth (10 rarest) 8

Philips SBC RU 098 Football Zapper, 1998

Every so often you come across a gadget that looks like it was designed by someone who was either high on drugs, or suffering from a serious mental disorder. What other explanation could there be for the Philips SBC RU 098 Football Zapper? It’s like a horrible genetic experiment gone wrong. What depraved mind could have conceived the unnatural mating of a universal TV remote control with a bottle opener?

On the other hand… Check out the date, it’s 1998, a World Cup year and my guess is the boffins at Philips were persuaded by the marketing department to come up with a gimmick to cash in on the football competition. Philips would have been promoting their TVs anyway; international events like the World Cup have always seen a big surge in TV sales -- especially high-end models. Booze makers would also be busy peddling their wares, so the Football Zapper was actually a marriage made in heaven. Who wouldn’t want to wind up the volume and celebrate with a beer watching their team score the winning goal (or switch channels and drown their sorrows in the case of England supporters…)?

Little or no new technology was involved in this hybrid design. The remote part is very similar to at least one other model in the Philips range at the time. There really isn’t much to say about bottle openers, except this one is a thick metal plate, sandwiched between the two case halves of the remote. This is imparts strength and leverage. Simply tacking a bottle opener onto the end of a remote box would quickly come to grief.

But back to the remote control part. It’s a fairly basic four-function design, able switch the TV on and off, mute the sound, step through the channels and turn the volume up and down. It can control several hundred different makes and models of TV and needless to say it’s factory set for Philips models. To program it for another make it’s necessary to either enter a 5-digit code, or use the Autosearch facility. There’s a list of manufacturers and codes in the back of the instruction manual. All you have to do is hold down the mute and power buttons for 3 seconds, an LED comes on and the code is entered by pressing the control buttons, each of which has been assigned a number from 1 to 7. After the code has been successfully entered the LED blinks twice and it’s set.

If it doesn’t work there’s usually a several alternative codes for each manufacturers and there’s the fallback of Autosearch. For this to work the TV has to be switched on. As before the power and mute buttons are pressed for 3 seconds then the power button and it starts stepping though the codes for turning TVs off. As soon as it does you have a second or so to press the power button to stop the search.

Philips gave this one to me at the press launch for their World Cup promotional campaign. It wasn’t a tricked up PR freebie but a proper retail product and I seem to recall that it was priced at £30 or thereabouts. I am happy to be corrected but the only thing I can remember is thinking was that it was way too expensive for a fancy bottle opener; World Cup or not… I came across it recently, still in its original packaging, in a box in my loft where it has remained undisturbed for almost two decades, complete with its original batteries. I neither know nor care if it works; it probably does but the TVs it was designed to control have long since disappeared so it is at least 50 percent useless, though the bottle opener is probably still okay…

What Happened To It?

Off the top of my head I cannot recall any other novelty or combo remote controls as crazy as this one. It might even be unique which, by rights, should make it quite valuable. Philips probably shifted a few of them but I have never seen another, or can find any record one selling on ebay. Back in the real world I doubt that any sane person or even football fan would pay more than a couple of pounds for it. But its day might come. I’ll be putting it back into secure storage for the benefit of future generations who will either marvel at its ingenuity and originality, or have a good laugh….

DUSTY DATA

First seen: 1998

Original Price: £30

Value Today: £2 (0117)

Features: Universal infrared TV remote control, 4 functions: power, mute volume & channel up/down, and integral bottle opener

Power req. 2 x 1.5v AAA cells

Dimensions: 170 x 58 x 40mm

Weight: 150g

Made (assembled) in: Singapore

Hen's Teeth (10 rarest): 7

Avid Pneumatic Airline IFE Headphones, 1970

Technically these Avid IFE (In Flight Entertainment) headphones are stolen property. However, since the felony occurred almost 50 years ago I think I am fairly safe admitting to my youthful misdeeds. It wasn’t exactly the crime of the century; back when they were new, in the early 1970s, they would have been worth only a few pence, a pound tops. That’s because they consist of just a few cheap parts: a pair of flexible tubes with a push-fit connector at one end, two soft rubber earpieces and a simple frame to make sure the earpieces stay clamped to the user’s head. There are no moving parts and they operate pneumatically, in other words they are powered by air. The connector plugs into a socket on the armrest of an airline seat and sound is piped, quite literally, from a pair of small speakers inside the armrest, up to the earpieces. It almost goes without saying that the sound quality was pretty awful and they became incredibly uncomfortable after only an hour or so.

Most airlines charged economy and coach passengers a fairly hefty rental fee, £2 - £5 as I recall, for the privilege of using them. Up the front of the plane, in business and first class, they were usually given out free. At the end of the flight they would be collected, cleaned and then reused. It must have been quite profitable for the airlines, though when asked why they cost so much the usual response was that the charge was to cover cleaning and/or royalties for showing in-flight movies. It’s hard to see how they couldn’t have made money. A single rental charge would have more than covered the cost of manufacture, and they were probably re-used scores, if not hundreds of times. What’s more the movies airlines showed in the early days – and there was usually only one, or two on a long-haul flight -- were often well past their view by date...

These and most other pneumatic headsets of this type were manufactured by a US company called Avid, who are still in the business of supplying equipment for IFE systems. TWA were the first to use them in 1963 and the development of in-flight entertainment was a clear attempt to boost ticket sales with the added bonus -- for the airlines -- of keeping the cargo, sorry, passengers, occupied and in their seats, especially during long-haul flights. It certainly had nothing to do with advances in technology. Similar systems had been around for decades and this was simply the cheapest and most reliable method of providing in-flight entertainment though terminals in the seats. Systems using conventional wired headphones had been developed but proved uneconomical, not only in terms of the hardware, but also the inevitable losses due to light-fingered passengers. That wasn’t so much of a problem with pneumatic headsets as they were next to useless for anything other than IFE, though a few did go walkabout.

Crafty passengers developed various strategies to avoid paying the charge, including using their own (probably pinched) headsets, though if they belonged to another airline – and you could tell by the colour or styling -- you had to make sure that the cabin crew didn’t spot you. Several companies made acoustic adaptors that plugged into the armrest socket. Inside the small box there was a pair of microphones and an amplifier and this allowed you to hear the movie soundtrack through a pair of conventional headphones. Again discretion was advised to avoid drawing attention to the piratical practice. There was also a bargain basement solution that involved constructing a small conical ‘horn’ from a piece of paper and poking that into one of the holes. If you lifted the armrest and put your ear close to the horn you could just about hear one of the two stereo channels, though only for a few minutes, before serious neck ache kicked in.

It all sounds quaintly prehistoric nowadays but apparently this system was still in use by at least one major airline (Delta) up until 2003, but that’s not the end of the story. Pneumatic headsets continue to be used to this day in specialist applications and we will look at a couple of them later on.

The maple leaf logo on the support frame indicates that this pair was issued by Canada airlines and it came into my possession during a flight from Toronto in 1970. It was one of several headsets I somehow acquired at around that time. More often than not it was simply a case of finder’s keepers, rather than pre-meditated theft. Sometimes you would find an unclaimed pair in the seat-back pocket or I discovered one that somehow ended up in my pocket, probably during a visit to the loo; it was easily done… This is the only one to have survived many clear-outs over the years; it wasn’t an especially interesting specimen, just overlooked, in the bottom of a box of junk in the garage.

What Happened To It?

The type of pneumatic headphones produced by Avid for commercial airlines lasted until well into the nineteen eighties but as aircraft were replaced or refurbished, IFE systems were updated and headphone jacks started appearing on seat armrests. The change was forced upon them by the runaway success of Walkman type personal stereos, which allowed passengers to carry their own entertainment systems with them. Airlines were left with no choice but up their game with more attractive multi-channel IFE offerings, using proper stereo headphones. This didn’t mean they willingly gave up on charging though, and to discourage passengers from using their own headphones, seats were fitted with a variety of proprietary or unusually configured connectors.

To be fair the very annoying twin mono 3.5mm jack arrangement had some justification. If there was a problem with the chair module resulting in a loss of signal to one socket, maintenance could be deferred and the seat could still be used. If an aggrieved passenger complained cabin crew could usually persuade, or bribe the traveller with goodies from the refreshment cart to put up with it, or do a swap with someone who didn’t want to use the IFE. It didn’t take long for aircraft jack adaptors to become available, though, so the airlines switched from renting to selling headsets and since they were usually cheap and nasty items, they could still make a decent profit. In the early days at least there were plenty of takers as not everyone remembered to pack a pair of head or earphones for every member of the family in their carry-on.

Now, back to those ongoing uses for pneumatic headphones, and they include hospital MRI scans. Scanners are noisy, intimidating beasts and one way to get patients to relax and stay still is to get them to listen to music. However, metal interferes with the scanner and conventional headphones are banned, but there’s no problem with an all-plastic pneumatic headsets. A similar setup is also used to check the hearing of newborn babies and infants. Pneumatic tubes and earpieces feed sounds to the children’s ears and their responses are monitored using an electroencephalogram (EEG), which measures brain activity. Precision-made plastic parts ensure accuracy and because they are sterile and cheap to make they can be disposed of after use.

Over the years millions of pneumatic IFE headsets must have been made but thanks to the rapid change to wired headphone sockets the vast majority of them would have been removed from service and destroyed. Some have survived, though, and there’s usually one or two on ebay at any one time. Prices are surprisingly high for such cheap (and useless) plastic items but that’s probably due to a thriving market in airline ephemera, rather than rarity or interest from collectors of vintage technology. The highest prices -- £15 - £20 -- are paid for unused headsets still in their sealed plastic bags, more so if they belong to large and defunct or small and obscure airline. Less reputable ones like these still have some value, though and because they are in good condition I have valued them at £10.00. I will probably hang on to them though, just in case the airlines ever bring them back. And if they start charging again I’ll be ready, provided they don’t change the design of the sockets...

DUSTY DATA

First seen 1963

Original Price £?

Value Today £10 (1216)

Features Two channel (stereo) operation, soft rubber earpieces, push-fit connector

Power req. n/a

Dimensions: Head frame 180 x 120 x 8mm, tube dia. 6mm, length 1 metre

Weight: 300g

Made (assembled) in: USA

Hen's Teeth (10 rarest): 7

Garmin GPS III Pilot Aviation GPS Receiver, 1997

Learning to fly a light aircraft is really not that difficult; learning how to get it safely from A to B without getting lost is the tricky bit. Incidentally, pilots never, ever, admit to being lost they become ‘temporarily uncertain of their position’… Getting the hang of navigation takes a while, or at least it used to. Before GPS navigation was taught using a fiendishly complicated widget called a Whizzywheel or to give it its proper name, a Flight Computer (that's my old one above). It’s a fancy circular slide rule and the idea is you set the compass bearing of the place where you want to go then the altitude and speed you want to fly followed by the wind speed and direction predicted at the height you’ll be flying. With a bit of jiggling and guessimation it shows the compass heading you need to take to compensate for the effects of the wind.

On a good day it could work perfectly, but sometimes it didn’t and you got lost -- sorry, temporarily uncertain etc etc… It used to happen a lot to student pilots, especially on early solo flights. Fortunately most of the time you’d see something on the ground that looked vaguely familiar or if you had time and fuel, you could use the old trick of following a major road, motorway or railway line and, in this country at least, sooner or later you’ll come to a large town, or the coast and from there you should be able to figure out your whereabouts on the map. There is also a last-resort solution and that’s to call a nearby airfield or airport, and with luck they can give you a ‘QDM’ or magnetic compass heading to their location, but that was only for wussies and dire emergencies. Later on in the process you get to play with radio navigation and learn how to use the directional beacons dotted around the country and at airfields. In the end, though most trainee pilots relied a lot on luck, having enough fuel to swan about the skies, and more importantly, being able to see the ground. In theory trainee pilots are not allowed to fly above the clouds or in poor visibility but crap happens, and not knowing exactly where you are, with the fuel gauge hovering on empty, would require a change of underpants, assuming you made a safe landing…

Then in the early 90s Global Positioning by Satellite or GPS changed everything. The old methods of navigating the skies didn’t disappear, though. Electronic devices can and do pack up, and getting someone to come and fix your instruments whilst panicking at 10,000 feet in heavy cloud is rather difficult, but these days pretty well all leisure and most commercial pilots rely heavily satellite navigation to get them safely to where they want to go. The Garmin GPS III Pilot was an early portable unit designed for this highly specialised market. Essentially it uses the same technology as earthbound GPS, it even displays some large roads but it is next to useless for finding your way around towns and cities. In fact the moving map display is of secondary importance and only shows large and distinct features that can be seen from the air, because you have to assume that a good deal of the time the ground is completely obscured by clouds.

The GPS III Pilot looks a lot like Garmin’s other portable units from that time. It’s housed in an odd wedge shaped case with a stubby antenna on the back. This can be swivelled around, to get the best signal, and removed so you can plug in an external antenna. The unit can be used hand-held but it comes with a dash mount bracket, to keep it safe and in clear view. The monochrome backlit LCD display is quite small but there’s the option of using large text and showing only critical information. It’s powered by four AA cells, though you really wouldn’t want to rely on battery power for flying and it comes with an external power adaptor that that plugs into a standard car cigarette lighter socket (common on many small planes) or powered directly from a light aircraft’s 24 volt DC main bus.

In spite of its size the display shows an astonishing amount of information. One button steps through a sequence of six ‘pages' and what follows is just a tiny fraction of the data it can be configured to show. Page one covers GPS acquisition, and you need a good lock on at least three satellites for so-called ‘3D’ navigation, which means showing your position in terms of speed, direction and the height above ground at your destination. Obviously knowing how high you are is quite important when flying, but once you've reached a safe height you just need to know you how high you, and all of the other aircraft in your vicinity, are above the common reference of sea level (so-called QNH). Lower down, when landing or taking off, your height above sea level becomes largely irrelevant and your main concern is your height above the hard, unforgiving ground (QFE), so you can avoid bumping into things…

Page two on the display is devoted to positional information. This shows what direction you are going, where you are, how fast you are going and other useful titbits like trip timers (for managing fuel use etc), and sunrise and sunset times, (handy to know if you are not qualified to fly at night). This is followed by the moving map display and it shows only the things that you can see on the ground, and the even more important things you can’t see, like the invisible borders surrounding airfields, aircraft traffic lanes, restricted areas, danger zones and so on. Next comes the HSI (Horizontal situation indicator) page that shows a large compass display with a course deviation bar. The compass shows the direction you need to steer to stay on course; a bar in the middle shows how far you are off track, so you try to keep it centred. There are also readouts for speed, distance and time to waypoint or destination. Page 5 is the only one that looks vaguely like a car GPS and this shows a sort of imaginary aerial highway that you have to follow. Lastly there’s the route page, which shows the ident codes of the airfields or waypoints you have selected and want to get to, the course you need to fly and the distance to each one.

One look at the 100 plus page instruction book is enough to tell you that it’s a formidable little gadget and not especially easy to use, compared with an in-car GPS. On the other hand once you have started flight training you quickly become familiar with its most important features and it starts to make sense. Setting it to guide you to an airfield using its ident code, for example, is no more difficult than programming an in-car GPS with a postcode but it is all the other things that it does, besides basic point-to-point navigation, that’s important, and what separates it from terrestrial GPS.

I bought this one in the late 90s, a few years after I got my pilot’s licence and it cost a small fortune, but it was worth every penny and got me out of trouble several times. It was quite a controversial purchase though, and at the time older pilots viewed the new fangled technology with some distrust. However, it quickly proved itself and within a few years GPS had become an almost standard fitment in light aircraft, though more traditional navigation methods definitely haven’t been abandoned and their use continues to be taught for reasons of safety and reliability.

What Happened To It?

There are no prizes for working out where the name Garmin came from, once you know that the company was founded in Taiwan in January 1990, by two electrical engineers called Gary Burrell and Dr. Min Kao. Needless to say Garmin, one of the pioneers of GPS technology, are still going strong and heavily involved in all fields of satellite navigation.

This particular GPS III Pilot had a lot of use in the late 90s and early noughties and it is still in great condition and full working order thanks to the very high quality of the materials and the standard of construction – after all, lives may depend upon it. At a pinch it could probably still be used, though the tiny screen makes it very hard going, compared with modern units, which have improved in leaps and bounds in terms of displays, accuracy and ease of use. However, the stored maps and database haven’t been updated for several years, if indeed they are still available for this device, so sadly its flying days are now over.

Vintage GPS units have yet to achieve collectable status, though there’s little doubt that some of the very first models, sold in the early 90s, are very rare indeed and could eventually have some historic importance to collectors of milestone technologies. It seems that quite a few GPS III Pilot’s were made between 1997 and the early noughties and most of them would have been very well looked after, so they are no strangers to ebay, especially in the US. Current prices for obsolete aviation GPS equipment bears little relationship to the original cost, or follows any particular pattern, which means you can pick up a working GPS III Pilot, for example, for anything between £25 and £200. Of course it is entirely possible that old GPS units could turn out to be a worthwhile investment but it seems unlikely you’ll live long enough to reap the benefits…

DUSTY DATA

First seen 1997

Original Price £400

Value Today £40 (1116)

Features Single channel differential ready Phase Trac receiver, 58 x 36mm monochrome backlit LCD display with screen rotation and zoom functions, positional accuracy 1 – 5 metres, acquisition times: cold start – 45 seconds; warm start - 15 seconds; auto locate – 5 minutes, update rate 1 second continuous, BNC antenna socket, RS-232 PC data interface

Power req. 4 x 1.5v AA cells & 10-32VDC (external adaptor)

Dimensions: 124 x 42 x 60mm

Weight: 168g

Made (assembled) in: Taiwan

Hen's Teeth (10 rarest): 5

La Pavoni Professional Lever Coffee Machine, 1985

As James Bond's gadgets go the La Pavoni Piccola -- seen briefly in his apartment in Live and Let Die (released in 1972) -- has a pretty low profile and most;y goes unnoticed

It was only on the screen for a few moments, at the beginning, but it was memorable for this classic, wry, one-liner from Bond’s MI6 boss ‘M’: ‘Is that all it does?’

Unusually for a Bond movie he wasn’t using it to save the world or destroy a super-villain’s lair, but to prepare a cup of cappuccino coffee (very badly, as it happens). However, its presence was more than just a feed line for M’s gag or mere product placement. It clearly signified Bond’s trademark suave sophistication and globetrotting lifestyle. It also helps to know that back in 1972 for most people coffee meant a cup of Nescafe instant. Cappuccinos and espressos were still widely regarded as exotic beverages and drank only rarely, if at all, on foreign holidays, in high-end restaurants or a handful of London coffee bars. The La Pavoni machine was the perfect prop for Bond, a real shiny eyeful and it could only have been made in Italy, where good coffee, style and design have near religious significance.

The apparently simple act of preparing a cup of coffee has spawned more gadgets and contraptions than almost any other culinary task. I’ve probably owned or tried most of them at one time or another, but this one is definitely a keeper. Nowadays it’s possible to get a half decent espresso or cup of coffee from a wide range of appliances but in almost all cases you are limited to a narrow range of options proscribed by the machine’s microchips, control software and flimsy mechanical components. And they’re not helped by the lack of variety in pre-packed capsules and podules and the often characterless ground coffees available in UK shops.

La Pavoni lever machines go right back to basics though, they’re purely manual contrivances, no pumps or presets and the resulting cups of coffee can be as good (or as bad) as you care to make them. Some coffee nerds even claim that it’s capable of the perfect espresso, the fabled ‘God Shot’, but the bottom line is that with care, patience, and a lot of trial and error it can make a damn fine tasting brew. The fact that this model has been in production, virtually unchanged, since the early 1960s suggests that the designers got it more or less right first time.

There are basically only two critical parts to Bond’s La Pavoni Piccola, and the one featured here, which is the near identical but higher capacity Professional model. They are the boiler, a sealed metal cylinder with an electrical heating element and the Grouphead, which is the doo-dad sticking out of the front with the lever attached. The boiler heats the water close to boiling point, raising the pressure in the cylinder to between 0.8 and 1.2 bar, causing a pressure switch or ‘pressurestat’ to turn off the heating element. At that point the lever is raised slowly, which draws a precisely measured amount of hot water into the grouphead. After a few seconds the lever is pulled down, forcing the water down, under pressure, into the portafilter containing a ‘puck’ of ground coffee, and then into the cup below.

It all sounds quite straightforward but the quality of the shot depends on a bewildering number of variables that real coffee nuts spend ages debating, and even longer trying to perfect. These include the speed at which the lever is raised, how long you wait before it is lowered, the pressure applied to the lever, how finely the coffee is ground, the tamp (how hard the portion of ground coffee is pressed into the portafilter), the nature of the water, local height above sea level (yes, really, and we’ll deal with that in a moment) and most importantly, the type or blend of coffee.

The height above seal level where the machine is used is important because if it is significantly higher or lower than Milan, where the machine was built, and the pressurestat switch set, it may need to be adjusted to compensate… Don’t mock, small details like that can become a serious issue for La Pavoni’s more obsessive users.

The real highlight, though, is the design, and don’t forget this bizarre looking contraption appeared several decades before Steampunk became a thing. The standout features are the upright shiny chrome boiler, pipework and safety valve; depending how old you are it either looks like it belongs in a mad Victorian scientist’s lab, or a proper old-fashioned Italian coffee bar. Then there’s the pressure gauge; it’s the real deal and actually means something to the user, not like those cosmetic fripperies fitted to many modern coffee machines. The sight glass on the side shows the water level in the boiler and ignore it at your peril! If the level drops too far there is a very real chance it will self-destruct. There’s more eye-candy in the shape of a big knurly knob on the back for the milk steamer and that huge lever on the front, and yes, it is like firing up a small steam engine with all of the whooshing and hissing noises, and as entertaining to use as it looks!

I found this La Pavoni Pro at a Surrey car boot sale and even through the layers of mud and grime I could see the chrome plating was sound and it was mostly intact, missing only a drip tray, so it warranted closer inspection. At that point having only a passing knowledge of these machines I had no idea what it was worth or even if it was salvageable, but since the stallholder was only asking £12 for it (haggled down to £8.00), and being a sucker for old coffee machines, I suspected that it could make an interesting restoration project. The stallholder claimed it was working but this turned out only to apply to the boiler’s heating element, everything that could wear out or perish had. As found the only way it could make coffee would be to heat up some water (very messily) for a lukewarm cup of instant.

Fortunately the Italians didn’t stint on materials; all of the metal components were in good order and the general build quality on this 1985 vintage model is excellent. La Pavoni are still in business so there’s a good supply of spare parts. The first job was to remove years of accumulated dirt and lime scale; several bottles of strong detergent and descaler later it was starting to look like its old self. The main problem, though, was the many rubber washers and seals inside the Group Head and pipe joints, which all leaked, gushing water and steam whenever the machine was switched on.

Rather than try and identify the ones that failed, or were about to go, I purchased a complete rebuild kit, and replacement drip tray costing £30. This forced me to strip the machine down to its bones and do the job properly, thoroughly cleaning every component. It was well worth the effort and after several run-throughs with clean water, to get rid of the last traces of descaler and rubber lubricants, it was ready to go. The first few espressos were very disappointing, though. It wasn’t until I tweaked the pressurestat switch, which determines how hot the water gets, read through several of the many websites packed with advice and techniques for La Pavoni owners, worked my way through half a dozen blends of coffee and bought a new bean grinder that I started to get the hang of it and make drinkable coffee. There’s still plenty of room for improvement, but that’s a big part of the appeal and whilst I doubt I’ll ever get close to a consistent God Shot, it’s fun trying.

Of course there are downsides The La Pavoni Pro is not the machine to have if you just want a quick cup of coffee. It takes a good six to eight minutes for it to get up to temperature and ten minutes plus for a good head of steam. It requires a fair amount of pressure to push down the lever, and if the boiler runs low and you want more coffee you have to depressurise the boiler through the steam wand, refill the boiler and wait for it to heat up again. The steamer pipe is a bit too close to the boiler for comfort and it’s quite fierce. It takes a while to get used to it and until you do it sprays hot milk over an impressively wide area. If you’re used to a conventional coffee machine you’ll find the portafilter latch is back to front, as it were, and all that chrome and pipework takes a lot cleaning to keep it looking nice and shiny.

What Happened To It?

The La Pavoni Piccola model featured in Live and Let Die first appeared in 1961. Over the years there have been many improvements but the way it works, and the outward appearance are still clearly recognisable on current Europiccola models, which sell from around £350 for a basic no-frills machine. The Professional model was introduced in 1983, doubling the capacity of the boiler from 0.8 litres, or around 8 espressos, to 1.6 litres, or 16 cups. Otherwise they are practically identical, apart from the price, and today’s baseline Pro model will set you back the thick end of £550. If money is no object you can easily spend half as much again on machines with a brass finish, wooden handles and accessories.

The eight quid my one cost was clearly a bargain, even after spending another £30 on the rebuild kit. For the record the washers and seals it uses are not that special and someone who knows their way around the high-pressure rubberware market could probably cut the cost of refurbishment by 50 percent or more. La Pavoni Piccola and Professional machines appear regularly on ebay; they rarely sell for less than £150, though £300 to £500 is more typical but on any used machine you would be well advised to factor in the cost of a grouphead rebuild. Fortunately this is a relatively straightforward DIY job requiring only basic tools. If you are lucky enough to find a cheap vintage fixer-upper don’t be put off; all parts are still available, though it pays to shop around as some items from authorised dealers can be quite pricey.

DUSTY DATA

First seen 1961

Original Price £?

Value Today £150.00 (1016)

Features 1.6 litre capacity, 0.7 – 1.2 bar pressure, 1000 watt heating element, pressure gauge, safety valve, steamer wand, water level sight glass

Power req. 230VAC 50/60Hz

Dimensions: 300 x 200 x 340mm

Weight: 6.2kg

Made (assembled) in: Milan, Italy

Hen's Teeth (10 rarest): 7

Ianero Quartzcolour Polaris Spotlight, 1980

Okay, so we’re a bit off the beaten track with this one, but it is common knowledge that every home needs a good reading lamp, and you’re going to have a hard time finding a better (or bigger) one than this Ianero Quartzcolour Polaris. Believe it or not it didn’t start out as a reading lamp and it required some minor alterations before it could be used as such. Prior to the modification it had the unfortunate effect of burning anything placed within its beam, but now it has been tamed it is a job that it does really well. The only minor problem remaining is to find a house with a living room large enough to fit it in...

It’s a stage or studio spotlight and vintage models that have been tarted up are now in demand for trendy interior lighting and really fancy, or really old ones can fetch a very pretty penny. The supply is finite, though and modern repros and fakes, many of them quite nasty and often grossly overpriced, are coming out of the woodwork. In fact movie style lights have always been popular and miniature models have been doing the rounds around for years, but this one is the real deal. It was made in the early 80s by the Italian manufacturer Ianaro and marketed in the UK through theatrical and studio lighting specialists Strand.

The reason this one was initially unsuitable as a reading lamp, apart from the size and weight, was the 1000-watt tungsten halogen bulb it uses. Not only does it get extremely hot, the beam of light it produces could probably fry an egg. Of course the powerful lamp can be substituted for an ordinary domestic light bulb but it is not an easy job without replacing the specialised 2-pin holder that is designed to withstand high temperatures. In the end I decided to leave it in its original condition and adapt an ordinary bulb. Now it uses a much more practical and electricity bill and environmentally friendly 3-watt LED light – more about that shortly.

Theatrical and studio spotlights turn out to be a good deal more complex than they appear from the outside. The moveable flaps or ‘barndoors’ on the front is the most noticeable, and familiar, feature and their function is pretty obvious, to define the limits of the beam, which as you can imagine can be quite handy for stage lighting. The big lens on the front is a Fresnel type; it works just like a conventional convex lens but it is flat, formed of a series of concentric prisms, which makes it easier to manufacture, and lighter too, because less glass is needed.

Most of the really interesting stuff happens on the inside, though, and behind the bulb there’s a fixed concave mirror, made out of polished metal. The beam angle can be varied between 9 and 60 degrees (narrow spot to wide-field) by altering the distance between the bulb and the mirror. The bulb is mounted on a moving platform that slides along a metal rail and this is connected to a control knob (the yellow one on the left side), via cables, driven by a set of pulleys and some gears. It’s an elegant and simple arrangement, and back in 1981 there was an option to control it remotely with a servo motor. There are two other control knobs on the right side (blue and white) and these are connected by a drive cables to mechanical actuators on the mounting bracket, to operate the lamp’s pan and tilt functions. There’s also a manual option; all three knobs have a socket fitting that couples with an attachment on the end of a long pole so adjustments can be carried out when the lamp is mounted out of easy reach. This one is configured for a stand mount, though, and the one it came with is a sturdy and very high quality item made by Arri, famous for its extensive range of video and movie cameras.

I came across this lamp, one of a pair, at a car boot sale in Kent, and having seen them previously at antique markets, often priced at several hundred pounds, I almost didn’t bother asking. But I did, more out of curiosity than hope, and was amazed when the stallholder said £60 each. It was still more than I was prepared to spend (or had about my person) so when the stallholder said he was open to offers I tried my luck with a cheeky £30 – about all that I had on me -- and was amazed when he accepted. He added that I could have both for £50. I’m kicking myself now for not snapping them up, though this would have entailed a trip to a cash machine and the nearest one was 5 miles away; the wife was also pulling faces, and it was starting to drizzle. I kid myself that they wouldn’t have fitted in my small car (they would, I would have made them fit…) but onwards and upwards, and it was still the bargain of the year.

Judging by the sticky labels it had recently been auctioned as part of a large lot of stage lamps. It was clear that it had been in use for some years but the scuffs and scratches were mostly minor. At some point the clamps on the stand had been painted over with white emulsion but that came off easily and they, and the barndoor flaps, were restored to an almost as-new condition with a quick rub down with some wire wool and coat of matt black spray paint. The lens, lamp housing and stand just needed a thorough clean. Once it was looking presentable and all moving parts lubricated, it was time to see if it worked. A continuity test confirmed the bulb was probably okay and the wiring was in good condition so power was applied and, nothing... The fault turned out to be the heavy-duty toggle switch on the side, which had gone open circuit. I could have replaced it but I decided to try my luck, take it apart and see if it was fixable. It was, just an accumulation of dried out grease and gunk on the contacts and ten minutes later it was back together and working.

At close quarters 1000 watts of highly focussed halogen light is a sight to behold (and keep you warm), especially in the confines of the average living room, but sadly the missus instantly banned it from ever being used at full whack, hence the swift changeover to an LED bulb. The modified holder was made using a disc of Bakelite (cut from a mains socket blanking plate), and drilled to take the two connecting prongs, which are a pair of 5mm bolts and solder tags. The connection to the bulb uses two short lengths of rigid 2mm copper wire, bent and soldered between the base of the bulb and the tags. It’s not pretty and probably contravenes numerous regulations but being an LED lamp it is only ever going to get a little warm and it is perfectly safe inside the housing. Nevertheless I am working on a more flexible arrangement, with insulated wiring and a proper bayonet socket, so bulbs can be easily changed.

What Happened To It?

Ianero in Italy are still in the business making professional studio and TV lights, so too is Strand Lighting, though it is now part of the Philips group. Nowadays both companies concentrate on sophisticated computer controllable LED-based systems; old style power-hungry and inefficient incandescent lamps like the Polaris have become virtually obsolete

That is part of the reason why so many stage and studio lights have been turning up at antique fairs over the past few years, as they are replaced with more up to date equipment, though undoubtedly there have been quite a few theatre and studio closures as well, contributing to the supply. There’s also a lot of phoney stage lights doing the rounds but these tend to be flimsily made, very unconvincing and quite easy to spot, pun intended.

Large old-school models like this one are becoming harder to find, though and as when they come on to the market in any sort of quantity they tend to be snapped up by upcyclers and interior designers, who generally sell them on at a very handsome profit. A lot of these lamps were designed for use on overhead gantries and have been clumsily (and sometimes dangerously) mated to unsuitable, lightweight camera, telescope and wooden theodolite tripods, and I dread to think what state the modified electrics might be in. A fair number of lights end up being stripped back to bare metal and polished, which to me looks a bit naff, and they’re going to be a pain to keep looking shiny.

Unfortunately bargain finds are few and far between; I doubt that I will ever see another one like this for the price. However, if you fancy one it is worth persevering and there have been some quite decent looking fixer-uppers on ebay recently for well under £100. Antique fairs are another good source but if you’re on a tight budget be prepared to get your hands dirty with some restoration and TLC. Also, given a choice, I recommend models that are quite a lot smaller than this one, unless you have enormous rooms, or live in a converted TV studio.

DUSTY DATA

First seen 1980

Original Price £198

Value Today £150 (0616)

Features 1kw Halogen lamp (CP40 bi-post quartz), 150mm Fresnel lens (beam range 9 – 60 degrees), manual pan, tilt & beam focus/control, side mounted power switch, colour/diffuser frame, four leaf 360 degrees rotating Barndoors, inc. Arri Trojan tripod base stand

Power req. 240VAC

Dimensions: 550 x 320 x 290mm (ex stand & barndoors)

Weight: 6kg (ex stand)

Made (assembled) in: Italy

Hen's Teeth (10 rarest): 6

Weller X-8250A Soldering Gun, 1953

Even those who regularly use soldering irons for work, DIY or in pursuit of a hobby would probably agree that they’re not particularly exciting, but this one really does deserve a special mention. It’s a fairly early Weller model, a classic ‘gun’ type design and tools like this have played a vital role in the development, manufacture and repair of countless electronic and electrical devices for more than half a century, and continue to do so to this day. As a matter of interest Weller’s company history claims that the circuit boards in the very first Apple computer, built in 1984 by Steve’s Jobs and Wozniak, was hand soldered using Weller tools.

Soldering guns differs from regular stick or wand type soldering irons in two very particular ways. Firstly they only heat up – to around 200 degrees centigrade -- when you pull the trigger, and for that to be useful it has to happen very quickly, typically in just 3 to 5 seconds. Secondly, they tend to be a lot more powerful than conventional irons, with heat outputs of 100 watts or more (this one is rated at 250 watts). Basically this means that they can solder large things that would quickly cool the tips of an ordinary iron, with wattages of between 15 and 25 watts. This has become less of an issue in the past few decades; nowadays most electronic devices are built using printed circuit boards populated with tiny heat sensitive components; big brutes like this can do more harm than good in confined spaces, but just occasionally there is a need to solder a thick cable or sizeable chunk of metal and only a soldering gun like this, with some serious grunt, will do.

Weller soldering guns, named after their inventor, Carl E Weller, from Easton Pennsylvania, began working on the design in his basement in the early 1940s and was granted a patent in 1946. A prototype of his first production gun, the Speedy Model B, is considered important enough to be on display at the Smithsonian Institute. Apart from the fact that the handle is made of wood it looks remarkably similar to this one, made in around 1953, and most of today’s models.

Like all the best inventions it’s really simple. The majority of modern soldering irons have a small mains-powered heating element in close contact with the pointed metal ‘tip’. The bent wire tip on Weller guns is the heating element and it heats up almost instantly when a high current, but very low voltage, is passed through it from a chunky ‘step down’ mains transformer. Because most soldering irons may be left on for hours on end the tips and elements can burn out quite quickly. It is wasteful of energy and when they fail they’re rarely worth repairing and have to be thrown away. The tip on Weller guns do eventually wear out or corrode (they’re made of a copper alloy) but replacements are cheap and they’re held in place by two nuts so it only takes a couple of minutes to fit a new one. As an added bonus since they only heat up when needed power consumption is comparatively low. Some models have a dual-action trigger with two heat settings, which makes them even more economical and most Weller guns have a built-in spotlight – this model has two – that illuminates the area around the tip. This is a genuinely useful feature when working in dark and inaccessible spaces, which according to Sod’s Law is where most solder related problems will occur…

There are a couple of downsides, though, and the most obvious one is that soldering guns are a bit too big and fierce for use on delicate electronic equipment. The transformer is also quite heavy – this model weighs in at 1.5kg -- so they can be tiring to use for long periods. They are also significantly more expensive to buy than common or garden soldering irons, but you’re paying for the power and one is usually all you will ever need. My first Weller gun lasted for more than 25 years before an unfortunate incident involving gravity and a hard concrete floor. This one is over 50 years old, and providing it stays out of harm’s way there’s every reason to suppose that it will still be going strong in another 50 years.

This Weller X-8250A was a recent find at a Surrey cart boot sale and I wasn’t about to quibble over the 50 pence asking price. The stallholder reckoned that it came from a house clearance and hadn’t been used for a very long time, confirmed by the fact that it was still fitted with an ancient round pin plug. It looked pretty grubby but the Bakelite case appeared to be in very good condition and the tip looked as though it had been little used. Mains powered devices are always a gamble at car boots, and potentially dangerous, so before I connected it up it was given a complete strip down, clean up and electrical check. The Bakelite case and tip holders polished up really well, thanks to some Brasso and a lot of elbow grease. The transformer, switch and cable all tested okay and with a new mains plug fitted it was time to power it up. It worked perfectly, reaching working temperature in just 2 or 3 seconds and since there were no smells, sparks or shocks it should prove to be a perfectly useable and useful tool.

What Happened To It?

Weller brand Soldering guns, and a very wide range of specialised tools and devices used in electronics manufacturing are still being produced but the once family-owned company has been a part of the Apex Tool Group since the 1970s. However, the design of the soldering guns has changed comparatively little over the years; plastic has replaced Bakelite making the cases more resilient and improvements in other areas have made them lighter and more efficient but in almost every important respect they're little different from Carl Weller's original design..

The X-8250A was originally sold as part of a kit, housed in a tough metal case with accessories that included a reel of solder a small spanner and a set of interchangeable tips for soldering, cutting and melting. Vintage models have become quite collectible, especially in the US, and very early designs and prototypes can fetch quite impressive prices. Complete and well looked after outfits dating from the 50s or 60s regularly sell for between £30 and £50 on ebay US. Well-used 8200 series guns – like this one -- are quite common though, a fair number were sold in the in the UK and the going price for a clean one is around £25.00. I can’t pretend that collecting vintage soldering irons is ever going to become a popular pastime, or a good investment, but if you’re any sort of DIY dabbler or handyperson a Weller gun in good working order is always going to earn its keep and the day will come when it's the only tool for the job.

DUSTY DATA

First seen 1953

Original Price $14.95

Value Today £10 (0516)

Features Trigger switch, 250 watts, 5-second heat up, twin ‘spotlights’, multi-purpose interchangeable tips

Power req. 240VAC

Dimensions: 270 x 165 x 55mm

Weight: 1.5kg

Made (assembled) in: USA

Hen's Teeth (10 rarest): 5

Horstmann Pluslite Magnifying Task Lamp, 1955?

Many of the items featured in dustygizmos owe their current state of well being to this desk lamp, which has a built-in magnifying lens. It has been sitting on my desk-cum- workbench, quietly earning its keep for the better part of 30 years. For much of that time I have barely given it a thought, until recently, when I acquired an Anglepoise magnifying desk lamp (coming soon). Whilst researching the Anglepoise I came across several references to my old desk lamp, and was surprised to discover that it has become a sought-after item of trendy decor.

This particular Horstmann Pluslite was manufactured in England, probably somewhere between the end of the 50s and the early 1960s. The basic design goes back to the 1940s, at least, and is known in the trade as a Task lamp. It was originally intended for a wide variety of commercial, engineering and industrial applications, from map reading to watchmaking, anything in fact that involves working on small things under strong illumination.

There are two prominent features: the lamp box and the cantilever mechanism, and we’ll begin with that. As you can see it’s designed to allow the lamp to moved to almost any position (up, down, forward, back), whilst holding the light at a constant angle. It uses a simple cantilever mechanism, similar to the one on the classic Anglepoise, but instead of springs compensating for the weight of the lamp, it has a large and heavy cast iron counterweight, and I mean heavy! The clever part is the way the cylindrical weight rolls back and forth as the lamp is extended, ensuring that the lamp is always perfectly balanced as the centre of gravity shifts. It is ingenious and led to this very distinctive style of lamp being called a ‘roller’. The manufacturer preferred to call it a Counterpoise mechanism, presumably in tribute to Anglepoise.

The lamp housing is made out of thin aluminium sheet, to save weight, and at first glance it doesn’t look particularly interesting, but lift up the hinged flap at the front and there’s a large glass magnifying lens hidden away inside. This folds out and clamps into position, so you can look through it onto the well lit object beneath. The lens has a 2X magnification, which may not sound much but it is exactly right for the sort of close-up work it is designed for. When the lens is folded away it functions happily as a normal, though rather complicated looking desk lamp.

All I can remember is that it came from a junk shop in Forest Hill, in South London, around 30 years ago, and I doubt very much that I paid more than £5.00 for it. It was then as you see it now, and apart from a wipe over for the camera; it remains in excellent condition with just a few marks to the silver paintwork here and there. The lamp holder has been rewired – the cable used to be a real trip hazard – and it’s probably on its third or fourth bulb, currently a 5-watt LED type – and that’s about the extent of the care and maintenance it has needed. There’s no reason to think that it won’t still be working in 50 or even100 years time, there’s simply nothing to go wrong.

What Happened To It?

Although this lamp is badged Horstmann the manufacturer is usually referred to as Hadrill & Horstmann and the logo on the magnifying glass cover features a double ‘H’. However, there is surprisingly little on the web about the company and its history, apart from the fact that it probably started at some time in the 1930s, and over the years produced at least a dozen different styles and types of table, task and floor standing lights. It seems that Hadrill & Horstmann ceased trading around 50 years ago and the name or business was bought up by the car parts manufacturer Simms in 1956. They went on to develop a series of classy looking desk and task lamps under the Simplus brand throughout the late 50s and 1960s but that’s where the trail goes cold. It’s going to take a lot more research to fill in the considerable gaps, so if anyone knows more (anything…) about the company, please let me know. It may not be a completely dormant brand though. The company name was recently re-registered at Companies House, key patents have been acquired and a graphics design company commissioned to devise a new logo. Could a revival of the iconic lamps be in the pipeline?

Time will tell but at the moment original vintage Hadrill and Horstmann lamps are being offered for sale at some frankly astonishing prices. I came across one late 1940s model in what was very kindly described by a dealer in retro-chic furniture as in ‘distressed’ condition (i.e. an absolute wreck) going for over £1000. The few I have seen on ebay are pitched between £200 and £500, and there’s several listed in auction catalogues and on antique dealer’s websites for similar amounts. Even the later Simplus models can fetch a very pretty penny so my one may well be worth a few bob. It is not for sale and still in constant daily use, though at some point I might re-assign it to less arduous decorative duties now that I have my new Anglepoise magnifier lamp, which has a more powerful 5X lens, and is better suited to working on small fiddly things, due to my ageing eyeballs.

DUSTY DATA

First seen 1955?

Original Price £30?

Value Today £150 - £300 (0516)

Features ‘Roller’ type weight counterbalanced (counterpoise) cantilever construction, 105 x 70mm fold-away glass lens 2X magnification, multi-axis lamp mount

Power req. 220VAC

Dimensions: 550/1020 x 380 x 160mm (folded/fully extended)

Weight: 6.5kg

Made (assembled) in: England

Hen's Teeth (10 rarest): 7

Seafarer 5 Echo Sounder, 1981

You can understand that knowing exactly how far it is between the underside of a boat or ship, and what lies beneath, is quite important to sailors. It’s a good way of avoiding bad things happening, following contact with sharp rocks and other hidden dangers, but until a little over a hundred years ago the only reliable method of determining the depth of a body of water was to drop a weighted, knotted line over the side and count the knots until it hit the bottom.

The sinking of the Titanic in 1912 prompted a flurry of research into marine safety. Inventors in both England and Germany came up with similar solutions inspired by the way bats and dolphins use sound to judge distances by a process known as echo location. The first patents for the system we now call Sonar (SOund Navigation And Ranging) were filed in 1913. At first glance it appears to be a fairly straightforward process; sound travels easily through water, at reasonably predictable speeds so all you have to do is to contrive some way to measure how long it takes for a pulse of sound, sent from the bottom of the vessel to bounce back from the seabed, and from that you can work out the distance.

In fact it took several decades for the technique to be refined and become accurate enough to be relied upon but by the Second World War sonar systems had become standard equipment on most naval and commercial vessels. Following the introduction of transistorised electronics in the late 1950 the size and cost of equipment had shrunk to the point where it became an option, and a major improvement in safety for smaller craft and the leisure fishing, sailing and boating markets took to it in a big way, which brings us to the Seafarer 5. This model dates from the early 1980s but essentially it relies on principles established more than half a century earlier, that are still in use today.

As you can see the Seafarer 5 is housed in a compact console, which would normally be mounted in clear view of whoever is steering the boat. There’s a minimum of controls, these include a two-position range selector (Shallow 0 – 18metres/0-60 feet and Deep 0-108 metres/0 – 60 fathoms). There’s a variable Gain control, which compensates for multiple echoes, caused by variations in the seabed terrain, depth and so on, and a shallow depth alarm, which sounds when the depth falls below a preset level.

However, the most important part of the Seafarer 5, and most other echo locators, is the depth display. Nowadays it’s usually a digital or graphical LCD screen, showing the depth beneath the hull numerically, in feet, metres or fathoms, or as a graphic or ‘chart’ type display showing the seabed contours. In contrast this model features an ingenious electomechanical dial, with a flashing LED indicating the depth against circular calibrated scales.

From the outside it looks like the dial is composed of a ring of LEDs but there’s only one. It’s mounted on a short arm, connected to a spinning disc that’s attached to a small motor. Flashing the LED at precisely the right moment as it whizzes around the dial shows depth indications. That’s quite a feat when you think about it and the way it works is really rather clever. On the underside of the disc on which the LED arm is mounted, there are a set of vertical blades, which interrupt a beam of light aimed at an optical sensor. All of the blades are the same size, except one, so the electronics – based around an early programmable microchip called a ULA (Uncommitted Logic Array) -- works out exactly where the LED is on its circular path. The obvious plus points are that only one LED is required, which simplifies the circuitry. The downside is that it involves a number of fragile mechanical parts, and needless to say everything has to be kept bone dry. It is prone to failure, noisy and care needs to be taken not to mount it too close to a magnetic field, like the one coming from a ship’s compass…

The unit has two power options, it can either run – for a limited time – on an internal 9 volt PP9 battery, which fits in a compartment on the back of the case, or it can be connected to the boat’s power supply and to accommodate wide variations it, this can be anywhere between 10.8 to 32 volts DC.

The other critical component is the transducer. This is a small waterproof module, which fits into a hole in the hull and connects to the Seafarer 5 by a cable. Inside the transducer there is a piezo crystal sounder/microphone that blasts out a 150kHz pulse (100 watts peak to peak), and picks it up on its return journey from the seabed. Sadly this vital part was missing on the one I have here.

Operation is very simple, the Gain control doubles up as the on/off switch, initially the LED flashes at the zero indication. The knob is turned slowly until a second reading is shown, indicating the depth.. There’s provision for a second digital repeater display, which would normally be mounted elsewhere on the vessel, in the cabin for example.

I landed this one at a local car boot sale. The stallholder’s opening offer price of £10, told me all that I needed to know about its probable condition. Originally it would have cost several hundred pounds and in spite of its age, in good working order I could see it fetching £20 or so in a marine equipment sale, maybe as a fitting for a 1980’s boat restoration project. It didn’t take much persuasion to get him to drop the price to £2.50, which confirmed my suspicion that it probably wasn’t going to be in tip-top working condition...

It wasn’t a surprise, therefore to discover that at some point water had got past the case seals but luckily it appears to have been of the fresh, rather than saltwater variety, so the visible damage wasn’t too severe. The case and parts inside all cleaned up well but the worst problem was a thin film of silt on the PCB and oxidisation on the spade contacts that link the PCB to the power and battery connectors on the back panel. This was easy enough to remove but the unit refused to power up. It is unlikely that the lack of a transducer is responsible, so at some point, when time allows it is going to require some serious troubleshooting. Surprisingly, though, what I supposed to be vulnerable components, like the LED display mechanism, slip ring contacts, and the motor escaped unscathed and they all worked when powered independently.

What Happened To It?

According to several 1980s boat and yachting magazines, rotating LED display, like the one used on the Seafarer 5 (and earlier versions, that used neon bulbs) were a mixed blessing. Whilst this type of display is large and very easy to read in all weathers and lighting conditions, reliability can be an issue, but the main complaint was a tendency for them to produce misleading ‘ghost’ indications, caused by multiple echoes. It’s difficult say when they eventually fell out of favour but by the mid to late 1980s unambiguous digital and chart type visual displays had become the norm.

Seafarer Navigation International Ltd, the manufacturers, also had a somewhat chequered history. It started out as a division of the Brocks Group, a collection of companies based in the Poole area, involved in diverse enterprises, ranging from marine electronics to sewing machines. The Seafarer brand was created in 1980 and appeared to thrive for several years but by the early 90s the company had been dissolved and Standard Communications bought up what was left of it, and there the trail goes cold.

During its brief existence it is possible that Seafarer made several thousand echo sounders like this one but my guess is that in the extreme conditions they were expected to work in, the failure rate would have been quite high. The new generation of models with digital and graphic displays put paid to mechanical displays by the early 90s, but Seafarer 5s and the later 700 model do turn up on ebay, and every so the seller claims that they are in good working order. Whether or not anyone would trust their lives to one of them is debatable so my guess is they’re of little interest to serious mariners. It’s hard to say who else would want to pay good money for one. The £2.50 I spent was arguably too much, but it was worth it to me, just to see how it worked. Maybe one day, when I get the time, it might be fun to try and get it working, but I doubt it…

DUSTY DATA

First seen 1982

Original Price £800?

Value Today £5 (0216)

Features Depth ranges: Shallow 0 – 18 metres (0 – 60 feet), Deep 4 – 108 metres (0 – 60 fathoms), analogue rotating LED display, presettable shallow water alarm (0,8 -- 30 metres. Piezo transducer (150kHz)

Power req. 1 x 9v PP9 or external 10.8 – 32v DC

Dimensions: 225 x 148 x 136mm

Weight: 1.4kg

Made (assembled) in: England

Hen's Teeth (10 rarest): 6

EMS Stammering Treatment Oscillator, 1969?

This is now officially the weirdest object in the dustygizmos collection. It’s a Stammering Treatment Oscillator and, according to a tiny logo on the front panel, it was made by a company called EMS, probably during the late 1960s or early 70s. Unfortunately I have been unable to find any evidence that this device ever existed, anywhere. Originally I suggested that EMS stood for Electronic Music Systems, which, if true would mean that it has a great pedigree. This British company pioneered electronically generated music and early synthesisers, including the legendary VCS3. Sadly EMS folded in 1979 and attempts to contact those involved have proved fruitless, so far, but there have been developments -- see the Update at the end of the item.

So what precisely is a Stammering Treatment Oscillator? Some of what follows is conjecture but there are several references to the use of low frequency sounds in the treatment of speech defects. The idea appears to be that carefully selected tones mask the patient’s ability to hear their own voice, which presumably helps in some way to overcome a stammer. However the devices described in the patents I have seen are considerably more sophisticated than this one, usually with multiple oscillators and additional features for automatically varying the frequency and inserting pauses and ‘metronome’ type beats into the audio output.

This device has a simple oscillator, amplifier and a headphone output on the front panel – and this, plus the build quality fits in with the renowned EMS being the most likely manufacturer. However, there is some additional circuitry, which is a bit of a mystery. It appears to be configured to generate a high voltage, which is fed to a second front panel socket, marked PB. This resonates with something that the chap who sold it to me said. He had no idea of how it worked but he claimed that the person who be got it from reckoned that it was designed to give the patient a shock, presumably to act as a deterrent, or diversion, to their stammering.

It sounds vaguely plausible. Electric shock treatment has, and still is used for a wide variety of complaints and maladies, including pain suppression. True, in times past it had a poor reputation as a dangerous quack remedy but nowadays it is quite respectable and not as barbaric as it sounds. You can even buy a Transcutaneous Electrical Nerve Stimulation or TENS machine in your local high-street pharmacist. These deliver a safe low-current, high-voltage, high frequency shock to the skin. The jury is still out on its efficacy but at the very least it takes user's minds off their aches and pains.

But back to the EMS box of tricks and the oscillator part. This is fairly straightforward; it’s a two transistor multivibrator circuit that generates a square wave tone of between 100 to 500Hz – there’s a control on the front panel -- which goes through some simple filtering and wave shaping circuitry. From there it is passes into a two-transistor push-pull amplifier that is connected to a headphone socket on the front panel, and a small built-in speaker mounted on the underside of the case. The purpose of the mystery circuit is a little harder to figure out. It looks a lot like a blocking oscillator, which is basically a transistor, a few other simple parts and the windings of a small step-up transformer, which together generates a high voltage. That theory is backed up by the presence of a neon bulb, inside the case mounted on the back of the circuit board. It cannot be seen from the outside so it’s of no use as an indicator, but it may be acting as a voltage regulator (neon bulbs typically ‘strike’ around 90 volts). If so it would limit the output to a high enough voltage to deliver a very lively tingle, but hopefully not enough to do any permanent damage…

This is all highly speculative of course so I would really welcome any experts in this field, or anyone associated with EMS to get in touch and either put me right, or point me in the right direction.

Unfortunately at this point it is not possible to say exactly what it does.. It’s as dead as a doornail and some rudimentary circuit checks suggested that at least two of the transistors are kaput. The electrolytic capacitors are also likely to be shot, or leaky, so they will have to be replaced as well. Old transformers and neon bulbs can be quite fragile and not having a circuit diagram is a major headache. It should be possible to reverse-engineer one but that it going to take time. On the plus side major components, like the germanium transistors, helps to date it to somewhere between the late 60s and early 70s. The wire wrap on matrix board construction is fairly easy to deal with when it comes to troubleshooting, and it’s typical of short production run items from that period. It’s also really robust and very well made so there is unlikely to be any serious wiring faults or dry joints. The steel case is built to last and in great condition, in fact the only thing missing is the Ever Ready 126 4.5volt battery packs, which are no longer made but modern (expensive) replacements are still available and it can easily be powered from a bench power supply.

I found it at a large open-air antiques fair in the Midlands; it was one of those cold and windy days when prices for oddities like this can be all over the place. The stallholder didn’t seem to be particularly attached to it and we both agreed that his opening price of £10 was a tad optimistic so we settled on a fiver. It was more or less as you see it now. There had been some corrosion around the battery holder but this cleaned up easily. It’s going to take a while to sort out the electronics but it’s definitely worth fixing, if only to discover what it actually does.

What Happened To It?

There were a lot of weird things going on in the sixties and seventies but my guess is that if electric shocks were ever a treatment for stammering, it wasn’t very successful, judging by the lack of references to it in modern journals. Modern speech therapies appear to concentrate on the underlying causes, in conjunction with vocal exercises, breathing techniques and so on, rather than pills and potions, or electric shocks.

Devices like this would not have been made in large numbers nor would many of them have them been kept by clinics and practitioners – this might even be the only one. Unfortunately that has little or no impact on what it is worth. I’ve put it at £10, based largely on the value of the case and the working parts inside. It might be more, especially if there’s anyone out there mad enough to collect vintage speech therapy devices, but if there is, they’re staying well hidden…

UPDATE 1 (October 2017)

My thanks to Brian Bottomley, the former Head of Medial Engineering at Calderdale and Huddersfield NHS trust, and clearly someone who knows what he's talking about! He writes to say that the manufacturer of the Stammering Oscillator may be Electro Medical Supplies, now known as EMS Physio. They are a long established business with a track record in electrotherapy products but there is no record of this particular device on their website. Investigations are on-going and as usual, if anyone can help to fill in the gaps, we would be very interested to hear from you.

UPDATE II (Nov 2017)

Electro Medical Supplies have confirmed that they were not the manufacturers. The mystery continues...

DUSTY DATA

First seen 1969?

Original Price £ probably a lot!

Value Today £10? (0116)

Features Variable frequency oscillator 100 – 500Hz, high voltage generator, audio amplifier, 8 transistors, built in speaker, headphone output, PB (?) connection, on/off volume control

Power req. 2 x Ever Ready 126 4.5 volt battery packs

Dimensions: 224 x 160 x 150mm

Weight: 2.5kg

Made (assembled) in: England

Hen's Teeth (10 rarest): 9

BayGen Freeplay Self-Powered Lantern, 1998

Torches tend to be largely uncontroversial things but this one, the BayGen Freeplay Self Powered Lantern, has a number of interesting and unusual stories to tell. These range from playing a part in the battle to stem the Aids epidemic in Africa, to scaring the pants off anyone daring to use one that’s more than a few years old…

It all began back in 1991 when multi-talented British stuntman, swimmer and inventor Trevor Baylis saw a TV documentary on the Aids crisis in Africa. It concluded that one effective way to help slow the spread of this terrible disease was education, and one of the best ways to inform people of the dangers in poverty stricken areas was through radio broadcasts. Unfortunately radios depend on a reliable source of power but in the places where Aids had taken hold this was often non-existent so he began developing the now famous wind-up Freeplay radio, using parts from an old transistor radio, toy car and a clockwork music box. After several years of struggle trying to find backers he eventually managed to secure investment and in 1997 he and his partners set up a company to manufacture the Freeplay radio in South Africa. The torch, featured here, appeared the following year, using a similar wind-up clockwork mechanism to the one in the Freeplay radio.

It’s a big torch, really big in fact, and heavy too, it weighs in at a not inconsiderable 2kg, and those were just two of the many reasons it wasn’t very successful, at least not in the UK, but there’s no denying that it was a clever and ground breaking idea. It’s more than just a torch, there’s an auxillary output socket so it can be used to power external devices that run on two AA type batteries. It has a DC input socket as well, for charging the battery. The torch comes with a spare bulb, it has a flash mode, which could be useful in emergencies and as an added bonus it runs longer between cranking sessions. Manufacturing the torch in South Africa fitted in with Trevor Baylis’s intention of providing employment and help for people in countries most affected by the Aids epidemic and it also meant that it was made in the area where it was needed and could be most useful.

These days most wind-up devices use a hand-cranked dynamo, connected to re-chargeable batteries to generate and store power. The first Freeplay radios and this torch have a clockwork motor, which seems like quite a good idea. There is no need at all for batteries (the radio also has a solar cell); power is stored by winding up a steel spring and it is released slowly, driving a small generator through a pulley and set of gears. The problem is, for it to run long enough to be useful the spring and drive mechanism has to be quite large and heavy. Even so this model can only manage around 3 minutes of fairly feeble light on a single wind, which takes between 30 and 60 seconds, but that’s only part of it. A fully wound spring contains a great of energy, that has to be safely contained. If a wound spring broke loose it could be really dangerous, which means that it has to be safely contained in a heavy-duty housing. Users also need to be sternly warned not to open the case or tinker with the mechanism.

Clockwork has other drawbacks, including requiring some means of stopping the spring from unwinding too quickly, and stopping the user getting whacked by the winding handle if they accidentally let go. On the radio this was solved by an electrical load on the generator, or the load of the radio, which acts as a braking mechanism. The downside of this arrangement is that the motor runs down, even when the radio is switched off

The torch uses a slightly different method. It has a mechanical brake that keeps the spring wound, so energy is stored when the torch is switched off. In theory this means it should always be instantly ready to use, powered from the wound spring, or the re-chargeable battery. The brake is connected to the on/off function switch, which is a good idea but the design is flawed. If the brake doesn’t engage securely, which can happen as the switch and mechanism ages, there is a very real possibility that after a full or partial wind the spring will release all of its energy in a matter of seconds. If you are lucky and take your hand away quickly enough you may avoid being hit by the whirring handle. It makes a terrible screaming sound, and the temptation is to try and grab the handle while it is spinning, but this will hurt and you will probably end up dropping it. The rapid release of energy almost certainly damages the mechanism and may end up destroying the motor.

This one is an early production sample, sent to me for review in one of the magazines I was working for at the time and it followed hard on the heels of the hugely successful Freeplay wind-up radio. I have one of those too, and it is still in daily use in my bathroom, but the shortcomings of the Freeplay Torch were immediately obvious. As far as I recall rather than write an unfavourable review I put it straight back in the box and it has been in my loft ever since. It is in absolutely mint condition, it still works and the nicad battery even holds a small charge. Unfortunately, though, the braking mechanism can be a little temperamental; if the on/off switch is moved even slightly from the off position the spring starts to rapidly unwind and super fast reactions are needed to stop it inflicting pain…

What Happened To It?

The bottom line is this original Freeplay torch was big and heavy with a weak light that only lasted for a few minutes. It was quite pricey and if the brake failed it would do its best to break your wrist. Sadly for Baylis his patents provided little protection for the wind-up radio and torch concept and within a couple of years they were coming out of the woodwork, the vast majority of them using more efficient, lighter, cheaper and longer lasting direct drive dynamos coupled to rechargeable batteries. Freeplay abandoned clockwork motors in favour of direct drive dynamos after a couple of years and this probably saved the company, which continues to make a wide range of wind-up and solar powered radios, media players, torches and mobile phone chargers.

I have yet to see another first generation Freeplay torch on ebay, not that I spend much time looking, but I am reasonably sure there’s not many of them around as apart from anything else they were quite expensive here in the UK. A slightly later Mk 2 clockwork model, called the Sherpa, pops up from time to time on ebay US but they tend to sell for just a few dollars, which suggests that it’s not yet a collectible. To be honest I doubt that it ever will attract much interest, or gain in value, at least not in my lifetime, but it deserves at least a footnote in the history of portable, energy efficient illumination. So, if you ever see one for a silly price, or on its way to the dump, rescue it, but make sure that you check the brake is working before you wind it up!

DUSTY DATA

First seen 1998

Original Price £30.00

Value Today £10.00 (0116)

Features Hand-cranked clockwork generator, folding handle, internal 700mA/h rechargeable battery pack, 2.3-volt 350mA Xenon ultra-bright bulb (plus spare), flash mode, aux power output (3-cols, 350mA DC), mechanical brake

Power req. Wind-up generator & 2 x AA nicad rechargeables

Dimensions: 250 x 170 x 140mm

Weight: 2kg

Made (assembled) in: South Africa

Hen's Teeth (10 rarest): 7

Telex MRB 600 Aviation Headset, 1980

This aviation headset may be familiar to several generations of student pilots, and if you are nerdy enough you might even recognise from walk-on parts in several movies, including The Hunt For Red October, made in 1990.

The Telex MRB 600 was a popular workhorse headset for the General Aviation (GA) industry for several decades for three very simple reasons, it was cheap, super tough and it worked really well.

For those unfamiliar with this sort of equipment it’s worth running through some of the reasons why the headsets used by aircraft crew are as different as chalk and cheese to the headphones you use to listen to your favourite tunes at home or on the move. To begin with they are fitted with microphones, so pilots can talk to each other, other crew members and, most important of all, air traffic control on the ground. These microphones are deliberately insensitive, to avoid picking up background noise from the engines, and in some light aircraft this can be painfully, and even harmfully loud. Aviation headsets have to provide high levels of noise insulation to protect the user’s hearing, typically encapsulating the wearer’s ears with thick cushioned pads, though nowadays most headsets use more efficient active noise reduction (ANR) technology. Comfort and weight are also hugely important considerations as they are often worn for many hours at a time; taking them off for a rest is not usually an option as apart from the interruption to communications the high noise levels would quickly become intolerable.

Because of the importance of reliable communications aviation headsets are regarded as safety-critical items of equipment. They are manufactured and have to conform to extraordinary high standards (The FAA TSO C57 & C58 are the recognised world standards) to ensure reliability, durability and compatibility, using the best components and materials, which inevitably means they can be very expensive. However, the Telex MRB 600s, when they first appeared in the early 80s, were notable for costing less than half as much as comparable headsets, making them popular with student pilots. Telex probably didn’t spend much time on the cosmetics but they definitely didn’t skimp on quality.

The microphone is mounted on an extendible lightweight aluminium boom that pivots though 180 degrees, so it can be on either side of the users head, or swivelled up and out of the way when the pilot wants to eat, drink or take a fag break (it was allowed in the olden days…). In normal use it sits within a centimetre or so of the user’s mouth. The design of the headphones might suggest that it’s a stereo setup but they are actually wired for mono sound, mainly because aircraft communication systems are mono, and also as a safety feature, so that if one headphone element or connection fails the other one should still operate. Each ‘phone is surrounded by a thick cushioned pad that envelopes the whole ear, and this is further protected by a cotton cover that provides further insulation and comfort, and it can be easily cleaned or replaced. The adjustable rubber-covered headbands are quite lightly sprung, so it can be worn for extended periods without discomfort. The thick connecting cable is very securely attached, to the frame and almost certainly means that it will survive if someone trips over the cable. The last notable feature is the twin jack plug connections. Whilst they look the same they are, in fact two different sizes. The one for the headphones is a standard 0.25-inch mono audio jack, the other one is very slightly smaller (0.206 inch) and this is for the microphone and its power supply. The reason they are different is simply to avoid mix ups.

Aviation headsets tend to be well looked after by their owners and can last for many years. There’s also a healthy market for good second hand models so they don’t turn up at car boot sales very often. When they do many people spot the microphone and mistake them for computer headsets but one look at the unusual twin plugs is enough to put them off, so I was quite pleased to find this one languishing in a pile of manky looking computer parts at a midlands boot sale, with all items priced at £1.00. Apart from the usual coating of grime it seemed to be all there and in well used, but generally good condition. It responded well to cleaning and even the cotton covers scrubbed up well, but the big question is, does it work? In a word, yes, the headphones are actually very good and although they’re optimised for speech frequencies, it makes a decent fist of reproducing music. The mike is a carbon type and requires a bias current to work so it can be a little tricky to test without a handy aircraft comms system. However, with a bit of messing around I was able to check that it was indeed functional and as soon as I get the chance I will try it out properly.

What Happened To It?

The Telex Corporation, which began as a hearing aid manufacturer in the 1930s is still with us, and making aviation headsets though it morphed into Telex Communications in the 70s when it was taken over by Memorex and it has since undergone a number of changes, most recently being acquired by the Bosch Group. Unfortunately these changes of ownership have made it difficult to track the progress of the MBR 600 but by trawling aviation industry trade magazines it is clear that it was on sale from at least 1980 to the early 90s, before it was replaced by newer models. However, such was the build quality of this headset that flyers today are buying and selling them for quite healthy sums (£50 - £100) and apparently still being used. For those not involved or familiar with the GA market buying and selling second hand headsets is a risky business and due to the safety aspect, best avoided. Boot sale bargains, although rare are well worth considering as vintage curios, display items, or as a collectible, and if you have soldering skills they’re easily converted into retro-style gaming headsets.

DUSTY DATA

First seen 1980?

Original Price £75

Value Today £25 (1215)

Features 2 x magnetic earphones, wired in parallel 150 ohm impedance, adjustable headband, carbon mike on telescopic swivel boom

Power req. n/a (powered by aircraft comms panel)

Dimensions: 230 x 180 x 75mm (boom mic folded)

Weight: 400g

Made (assembled) in: USA

Hen's Teeth (10 rarest): 7

Seafix Radio Direction Finder, 1968

Usually it’s not too difficult to work out precisely where you are, in fact in it is virtually impossible to get properly lost on our small, crowded, accurately mapped and signposted island, but it can get a bit tricky when you are at sea and out of sight of land. Within the past three decades highly accurate navigational aids, like GPS, have taken almost all of the guesswork out of determining your location. Before that figuring out your position on the world’s oceans -- with any degree of accuracy -- required a certain amount of knowledge, skill, good charts, a little luck, and a gadget like this Seafix Radio Direction Finder.

It’s a simple idea; until a few years ago hundreds of radio beacons were strategically located around the world’s coastlines, beaming a continuous stream of identity letters in Morse Code. To plot your position all you needed was a highly directional receiver, tuned to the frequency of a nearby beacon and by aligning the receiver’s antenna, to the ‘null’ point, where the signal disappeared, you could take a compass bearing then draw a line on your chart to the beacon and be fairly certain that you were somewhere along that line. To pinpoint your position all you needed to do was take one or more bearings from other beacons, and where the lines intersected was pretty much where you were. In practice there was plenty to go wrong, and lots of tweaks and fiddles that had to be applied to plots and readings to compensate for various natural and man-made anomalies. Even experienced navigators could still be a few nauticle miles off course, but it was usually good enough to get vessels to where they wanted to go.

This Seafix radio direction finder (RDF), which looks a lot like a Police speed camera, was a fairly basic model and mainly designed for use on smaller vessels that didn’t stray too far from the coast. This also means that it has few controls so it is easy to use, ideal, in fact, for amateur and weekend sailors, in well-charted waters.

There are two main components, an accurate liquid-filled compass on the top, with a prismatic pointer, so you can line it up on landmarks and take a readings, The other part is a simple 4-transistor AM receiver that tunes over a frequency range of 200 to 400kHz. This is a portion of the Long Wave band used by non-directional beacons (NDBs), as well as various broadcast stations, including the BBC’s Radio 4 Long Wave service. Long Wave signals have the useful property of travelling very long distances, following – to some extent -- the curvature of the Earth. Higher frequency transmissions on Medium Wave and VHF are generally only receivable within a few tens of miles of the transmitter.

The key feature of the Seafix’s receiver is a ferrite rod antenna, which is the directional element. The strongest signal will be received when it is at right angles to the transmitter and it will virtually disappear – the so called ‘null point’ -- when it is pointing directly at (or away from) the beacon. This last point is important because a compass reading taken on a RDF can be 180 degrees out, so it is vitally important that the user takes readings from at least one other beacon and plots them on an up to date navigational chart. To help the user identify beacons a copy of the Morse Code is moulded into the battery cover on the front of the receiver case. Other distinctive features include a removable handle with a lanyard, so the unit can be used handheld, or on some sort of fixed mounting. The receiver case is a square-shaped plastic tube, with weatherproof seals at each end, and the compass is mounted in a sliding holder so it can be removed and inserted the other way around.

To use it all you have to do consult your navigation chart and identify the nearest beacon – preferably one within 50 or so miles of your estimated or last known position -- and take a note of its frequency and Morse Code ident. Plug in the supplied headphones, switch it on, set the approximate frequency on the dial, and start hunting. As soon as the beacon has been found the RDF is rotated until the signal disappears, at which point a bearing can be taken on the compass. At night or in poor visibility there’s a built in illuminator lamp that shines up on to the compass.

A large car boot sale Dorset, was where I found this one, not too far from Poole, which has a large marina and almost certainly where it came from, when it was last used in anger. The stallholder, clearly not a nautical cove, wanted £5.00 for it, even though it was in a filthy and dilapidated state. He didn’t know where it came from, what it was for or if it worked. We briefly discussed the matter and agreed on a much more realistic sum of £2.00. After getting it home and cleaning it up – and under the gunk it was in surprisingly good condition -- I found signs that at some point one of the batteries had leaked; luckily it hadn’t corroded the contacts and the dried out deposits brushed away. The only other minor issue was the compass. The damping fluid, probably some sort of light mineral oil, had either been drained or it had leaked. The compass still works but takes ages to settle down. The seals and threaded plug on the underside are intact so it should be easy enough to refill, which I will do one day, when I find out what sort of fluid is used. With a set of batteries installed I was pleased to find that all of the receiver functions worked perfectly, allowing me to both listen to The Archers on Radio 4 and determine that the BBC’s Long Wave transmitter is on a bearing of 310 degrees (magnetic) from my South London location. Sadly there were no working beacons in range so I’ll have to use more traditional methods to figure out exactly where I am.

What Happened To It?

Unfortunately it is next to useless; nautical RDF was driven into obsolescence by GPS and most NDBs were decommissioned by 2008. A few remain, and it is theoretically possible to use it to triangulate on aircraft beacons but these tend to be inland, so reception is patchy and you probably wouldn’t want to rely on it. The manufacturers, a British company called Electronic Laboratories suffered a similar fate and the company, which appears to have had few other strings to its bow, other than RDF, persevered with several more advanced models in the 80s and 90s, was eventually dissolved in the mid noughties.

RDFs like this one have only novelty value and as fairly poor receivers of a handful of Long Wave broadcasts but that doesn’t mean they should be forgotten or discarded. RDF played a vital part in the long history of navigation on the high seas and over the 50 or so years it was in operation it was responsible for helping countless seafarers to safely reach their destination, no doubt saving many lives in the process. It’s also an excellent way to demonstrate the rudiments of radio navigation, though these days, with a GPS and highly accurate maps available on most smartphones, map reading has become something of a lost art. Basic models like this one have yet to become serious collectibles and probably won’t go much up in value anytime soon, but if you see one, and the price is right, grab it. Trust me, their day will come and sooner or later one will pop up on the Antiques Roadshow and prices will surely soar…

DUSTY DATA

First seen 1968

Original Price £25

Value Today £10 (1215)

Features AM receiver 200 – 400 kHz (navigational & broadcast bands), 4 transistors, ferrite antenna, rotary tuning, variable sensitivity, oil filled compass with sighting prism, switchable illuminator lamp, audio output (3.5mm jack), removable handle & lanyard, Morse code embossed on battery cover

Power req. 6 x 1.5-volt AA cells

Dimensions: 180 x 265 x 80mm (mounted handle & compass)

Weight: 950g

Made (assembled) in: England

Hen's Teeth (10 rarest): 6

Eagle International Loudhailer, 1970?

Since you ask, because it was there, £1.50, and no, I have no particular need for a loudhailer, megaphone or bullhorn – call it what you will -- at the moment… It is something I have always wanted though, for no very good reason except that they look like a lot of fun to play with. It would have been difficult to justify buying one on a whim, so when I spotted this one at a car boot sale, with an asking price of a fiver I couldn’t resist. A quick thirty-second haggle later and it was mine for the aforementioned bargain price of thirty bob.

It’s badged Eagle International, who were quite well known from the 60s to the late 80s for a range of budget-price audio and electronic products. I remember it as one of those cheap and cheerful brands that were good at leaping onto bandwagons, but never managed to produce anything particularly remarkable or innovative. Their stuff was cheap, though, so it was no great loss when it eventually packed up.

This loudhailer is an exception. It is very well made though precisely when that was, or its exact model number are all a bit of a mystery as almost all of the labels have disappeared. My best guess is that it was made in the early to mid 1970s, almost certainly in Japan. That is based largely on the materials (mostly metal) and the components in the amplifier module. Unfortunately there are few clues in the design or styling. On the outside loudhailers haven’t changed much over the years, indeed, many of today’s models look uncannily similar to this one. Collectors of vintage megaphones are probably few and far between but if anyone out there can fill in the gaps, please let me know.

Judging by the design of the amp – a simple push-pull configuration – and the transistors (germanium types) I suspect that it has an output of around 15 watts. It drives an 8-ohm horn speaker and it is powered by eight 1.5-volt C cells, which live in the cylindrical compartment behind the horn. There’s also a socket on the side for an external 12-volt power supply.

There are a few noteworthy features, starting with the detachable hand-held microphone. This is an ‘anti-howl’ type, which is supposed to reduce, or eliminate the characteristic high-pitched, howl-round, or acoustic feedback, caused by the mike picking up sounds from the speaker, and feeding it back into the amp, making it oscillate. It involves having two microphone capsules in the hand-held mike, wired together, in opposite phase, across a potentiometer that adjusts input level. Two features are designed to attract an audience’s attention. The first is a built-in siren; the other one is a red light, mounted on the front of the horn speaker. It is easy to use with just a handful of controls. There are two press-to-talk (PTT) switches, on the side of the mike and built into the megaphone’s pistol grip and a three-way slide switch on the side of the unit selects power on/off and siren mode.

The lack of interest from other car-booters was understandable. It looked in a very sorry state with the horn and microphone covered in crud and wires hanging out of the mike plug. The clasp that holds the battery cover in place was hanging off and it looked like it had led a hard life, with chipped and scraped paint on the handle and rim of the horn. However, the battery compartment looked clean enough and it takes more than a couple of loose wires and a few scuff marks to put me off…

I wasn’t too surprised that it didn’t work after the cover clamp and plug connections were fixed, though the speaker gave an encouragingly loud pop, which suggested that the amp was probably okay. The first hurdle was figuring out how to take it apart. It turned out to be a bit of a nightmare with lots of hidden screws that could only be reached with an extra long and thin screwdriver, and a torch. When I finally managed to separate the two sections and remove the amplifier module I was confronted by a rat’s nest of wires, several of which had come adrift. Others were hanging by a thread, so the first thing to do was take some photos so there would be a reasonable chance of getting them back to where they belonged when they broke away.

Luckily it was fairly obvious where the wayward cables had come from so once it was reassembled it was time to give it another try. It remained stubbornly silent but a few quick prods with a signal injector pointed to the trouble being at the front end, at or around the mike. The problem turned out to be a half-arsed attempt to solder a loose wire on the mike socket and once that was fixed it sprang into life, and it is pretty loud!

What Happened To It?

No doubt someone, somewhere, has written a history of the amplified loudhailer (as opposed to entirely passive, shout-though megaphones…) but if it exists I can't find it. My guess is the earliest examples appeared somewhere between 1910 and 1920, coinciding with the development of triode valves, the key components in the first audio amplifiers. Police ‘bullhorns’ regularly appear in gangster movies made in the 30s and 40s but apart from improvements in amplifiers, batteries and materials, from the outside modern ones don’t look significantly different to vintage models. The back-story of Eagle International is also difficult to pin down and whilst the name or brand lives on, the trail of the company responsible for making or marketing this particular model goes cold in 2000.

I am under no illusion that loudhailers from the last 40 or 50 years are of little no interest to anyone but me, and possibly a handful of like-minded technology nerds, but really old ones – pre 1950s say – almost certainly are worth something. If nothing else they appear to be extremely rare and occasional searches on ebay for ancient valve-based units have proved largely fruitless. The £1.50 I paid for this one was a very good deal, but the car boot stallholder’s original asking price of £5.00 probably wasn’t too far off the mark. It is still useable but I wouldn’t be confident using it for making important announcements. If you want one for its intended purpose then you would be better off splashing out £20 - £30 on a modern example, which I suspect would also be lighter, louder and more reliable. On the other hand it wouldn’t have a fraction of the character of a vintage model like this one, and who knows what momentous or historic voices and words came out of that horn?

DUSTY DATA

First seen 1970?

Original Price £30?

Value Today £10 (1115)

Features 4 transistor amplifier approx 15 Watts RMS, 8-ohm horn speaker, siren, attention light, detachable anti-howl microphone, external power socket, carry/shoulder strap

Power req. 6 x 1.5-volt ‘C’ cells, 12VDC external

Dimensions: 400 x 220mm

Weight: 2kg

Made (assembled) in: Japan

Hen's Teeth (10 rarest): 5

Pifco 888.998 Lantern & Spotlight, 1965

It may not be the most high-tech product on these pages but take it from me: back in the 1960s this Pifco safety lantern was at the cutting-edge of multi-purpose portable illumination technology, and a real must-have for boys, of all ages.

Check out the snazzy features; it has a pivoting spotlight, producing a ‘brilliant beam’ according to the box it came in, and on the top there’s a dome lamp that flashes; it even comes with a choice of clear and red coloured domes (the latter is sadly missing on this example). It’s a multi-mode design with a sliding switch on the back that selects spotlight only, flashing dome, or both together, and the carry handle rotates through a full 360 degrees. Who wouldn’t want one? It was just the job for motorists, campers and power cuts, which were a fairly common event in those days.

This one is made by Pifco, it has no name or model number but it is stamped ‘UK Design No. 888.998’ and ‘Empire Made’ (Hong Kong) and identical to the one that I proudly owned back in the day. I had forgotten all about it but by chance I stumbled across a couple of pages of them selling on ebay for frankly stupid money, touted as ‘retro chic’ lanterns for trendy glampers and caravanners…

To be fair it is an eye catching design, very much of its time, and apart from the dome and front lens, it is all metal construction, which made it as tough as old boots. Sadly, these days the ‘brilliant beam’ looks a bit yellow and feeble, compared with even the cheapest of today’s LED torches, and it’s quite a lump too, to accommodate that enormous 6 volt battery pack, which, incidentally only lasts for a couple of hours. Nevertheless, it does the job it was designed to do superbly well (everyone ate lots of carrots in the sixties, we all had better eyesight and we didn’t need bright torches...), and with prices going the way they are, it’s well on its way to becoming a collectable.

Whilst prices on ebay are on the way up it is still possible to find fairly decent examples, like this one, at car boot sales and flea markets. At the Surrey car boot where this came from I didn’t have the nerve to haggle with the stallholder over the 50 pence asking price. He reckoned it worked but apologised and said he couldn’t test it because the batteries were no longer made. By pure coincidence I spotted a stall a couple of rows away that were selling the 6 volt 4R25 battery it uses for just £1.50, and I have subsequently seen them in several high street stores, like Wilkinson and Robert Dyas for well under a fiver.

The condition was pretty good, just a few scratches, one or two specks of light surface rust and the chrome plating was bit tarnished in places but it was nothing a quick rub-down with some Brasso couldn’t fix. As you can see it scrubbed up well and everything works just fine, even the flashing dome. By the way, this is a particularly clever feature as the flasher is built into the MES (Miniature Edison Screw) torch bulb. If you look closely at the photo you may just be able to see a tiny bi-metallic strip, connected to one of the two conductive supports for the filament. When the bulb is on it quickly heats up and this causes the bi-metal strip to bend slightly, breaking the circuit. The bulb then cools down, the bi-metal strip returns to its former shape, the contact is re-made, the bulb comes on again and the cycle repeats, flashing the bulb every 2-3 seconds. I will only be using this one on special occasions though, birthdays and holidays and so on, as these specialist bulbs, whilst still available, probably won’t be around for very much longer.

What Happened To It

Pifco or the Provincial Incandescent Fittings Company was founded in Manchester back in 1900 and it is still going strong today, distributing all sorts of useful household bits and bobs from around the world, though the current line-up doesn’t seem to include any torches. It is difficult to be precise about the chronology of this design but it was definitely around in the early to mid 1960s, and I’m sure I recall seeing this self-same model on sale well into the seventies. The shape evolved over the years, though, and from what I have seen later models have flat topped ‘domes’, a slightly larger spotlight and the wire handle morphed into a handy stand, so the whole lamp could be tilted, but essentially it was the same tried and tested design.

Chunky metal lanterns like the 888.998 couldn’t last, though. They must have been expensive to make; plastic was a whole lot cheaper and manufacturers could be much more adventurous with their designs, yet under the skin torches and lanterns remained virtually unchanged until the mid to late eighties. At around that time lantern technology took a big leap forward following improvements in rechargeable NiCad and sealed lead-acid batteries and the introduction of low voltage halogen bulbs. This resulted in a rash of bulky but very powerful hand-held flashlights – mostly coloured yellow for some reason -- with claims of millions of candlepower light outputs. The really big change, though, came with the introduction of high-brightness white LEDs and by the late 90s they were becoming cheap enough to use in everyday torches. LEDs are much more robust than traditional incandescant torch bulbs, they last almost indefinitely and use significantly less power for a given light output, but initially the only way to create a respectably bright beam was to use multiple LEDs. By the mid noughties single high-power LEDs started to appear and have subsequently fallen in price to the point where they are now the bulb of choice for almost all serious torches and lanterns.

This is excellent news for collectors of vintage torches and lanterns, and if this isn’t yet a popular hobby it probably will be soon, judging by the prices being asked for old lanterns like the 888.988 on ebay. Even manky ones seem to be going for upwards of £15 to £20, so get in quick, while they can still be found for a few bob at your local car boot. Who knows, a complete set of boxed Pifco lanterns from the sixties and seventies could one day provide a welcome boost for your retirement fund…

DUSTY DATA

First seen 1965

Original Price £5?

Value Today £15 (1015)

Features Hinged spotlight (5.5-volt, 2.5 watt PR13.5S bulb) with polished steel reflector, flashing light (MES type flashing bulb) with clear and red coloured domes, slide switch for three-mode operation (spotlight, dome & both together), adjustable carry handle

Power req. 6-volt 4R25/PJ996 lantern battery

Dimensions: 170 x 90mm (195 x 145mm inc. spotlight & handle)

Weight: 400g

Made (assembled) in: Empire Made (Hong Kong)

Hen's Teeth (10 rarest): 6

Micronta 3001 Metal Detector, 1979

‘Get that bloody thing out of here…’. That’s a sanitised summary of what the policeman behind the desk at North Chingford’s cop-shop said to me when I proudly presented him with a mostly intact WW2 incendiary bomb. I suspect what might have concerned him was the white substance oozing from the corroded casing. The last time I saw it, it was sitting in a bucket in the middle of the deserted police station car park.

This was one of the first and certainly the most interesting things I ever found with my home-built metal detector, (from plans in ETI magazine), back in the late 1970s. I had been waving it around my back garden and nearby fields and forest for several hours and apart from the small bomb (which came from the forest) all I ever managed to find was lots of ring-pulls, aluminium foil from fag packets and a washer or two. In short it was huge disappointment and my hopes of discovering buried treasure quickly fizzled out.

Perhaps, if I had owned one of these, a Micronta 3001, which was sold in Tandy stores at around the same time, I might have persevered. Within a few minutes of getting this one home from the boot sale I managed to find three old toy cars, numerous nuts, bolts and bits of rusty metal, two tops from fish paste jars, 3 old pennies and a sixpence; it was already paying for itself…

In the scheme of things the Micronta 3001 is only one step up from a toy metal detector, and nowhere near as sensitive as today’s ‘pro’ detectors but it really does work and it can find smallish metal objects like coins at a depth of a centimetre or two. It also has a rudimentary discriminator facility and supposedly can tell the difference between ferrous and non-ferrous metals, though to date gold and silver objects have proved elusive.

The key component is the 180mm (7-inch) diameter search coil, mounted on a hinged joint at the end of a telescopic pole. The other end is attached to the hand-held module – more on that in a moment. There are actually two coils, one sends out a low power radio frequency signal, which is picked up by the second coil. Under normal circumstances the transmitted and received signals are the same but if the coil passes over a metallic object the electromagnetic field is disturbed and this change is used to generate a tone. The tone rises and falls in pitch and volume according to the size and proximity of the object. Controls on the hand-held unit alters the frequency and threshold, or point at which the tone is generated allowing the user to fine-tune sensitivity and discriminate between ferrous and non-ferrous metals. The strength of the signal is also displayed on a simple meter and there’s the option to plug in a set of headphones, for a spot of discrete detecting. Inside the case there’s a remarkably simple circuit board, just 4 transistors plus a handful of passive components. It is powered by six AA cells, which live in a compartment on the underside of the hand-held unit. For the record markings on the PCB show that a Chinese company called Alert manufactured it and further research indicates they were responsible for several other metal detectors in the Radio Shack range.

It only takes a few minutes to get the hang of using it and by changing the speed and direction of the sweeping motion it’s easy to pinpoint and gauge the size of a buried object. Very small objects can be found by digging out chunks of soil at a time, depositing them to one side and re-testing each one in turn.

This 3001 came from a Surrey car boot sale. The stallholder wasn’t sure if it worked but it looked like it had been well looked after and was in pretty good shape. The battery compartment was clean so after a very brief haggle a price of £2.50 was agreed. A short while later, with a set of batteries installed, it burst into life and it proved to be impressively sensitive; as soon as time permits I’ll give it a proper test run.

What Happened To It?

The 3001 was a remarkably long-lived product, first featured in the 1979 edition of the Radio Shack catalogue, listed as the ‘Standard’ model and costing $39.95. I can recall seeing it in the UK Tandy catalogue at around the same time and working on the typical dollar pound conversion rates at the time I suspect it sold on this side of the pond for somewhere £25 and £35. It remained virtually unchanged until its last appearance in the 1997 catalogue; the following year it was replaced by much sleeker and more sophisticated version, though for some reason the 3001 model number was retained. By the way, in case you are wondering how I know so much about Radio Shack catalogues, it’s because there’s a brilliant online archive, covering the years 1940 to 2011. Fascinating stuff for gadget collectors.

Metal detectoring has been a popular and somet