Capturing Light In A Vacuum: The Magic Of Tube Video Cameras

November 1, 2024 by Jenny List 33 Comments

Cameras are a funny rabbit hole to fall down as a hacker, because we have well over a century of items to pick and choose from, a lot of which can be had for relative pennies. In my case I have more of them than I’d care to mention, mostly film cameras and 8mm movie cameras, but there are one or two that are entirely different. My first interest in electronics came through PAL televisions, so it’s hardly surprising that along the way I’ve also acquired more than one chunky old tube-based video camera. These devices are now long ago supplanted by their solid state replacements, but they retain a fascination for me as the mirror of the CRT-based TV sets I know so well. It’s time for a fascinating descent into the world of analogue video.

Electrons chasing light, chasing electrons

The zig-zag line pattern of a TV scan. — A raster scan pattern. Ian Harvey, Public domain.

The basic mode of operation behind all but some of the very earliest electronic camera tubes is that an electron gun paints its raster of electrons onto a light-sensitive target, and the current flowing through the electron beam varies in proportion to the light at each particular point on the target. This can be used to create a voltage, which when combined with the various sync pulses makes a video signal that would be understood by a monitor. The various different types of tubes have names such as Iconoscope, Emitron, or Vidicon, and while the main differences between those various types of tube lie in the combination of materials and design of their targets. Successive generations of tube made improvements to sensitivity and noise performance, first combining photoemissive layers with electron multiplying layers to amplify the video signal in much the same way as a photomultiplier tube does, and then using photoconductive targets to vary the conductivity of the target depending on the light at a particular point. Continue reading “Capturing Light In A Vacuum: The Magic Of Tube Video Cameras” →

3D Printing With A Hot Glue Gun

October 31, 2024 by Jenny List 14 Comments

Face it, we’ve all at some time or other looked at our hot glue guns, and thought “I wonder if I could use that for 3D printing!”. [Proper Printing] didn’t just think it, he’s made a working hot glue 3D printer. As you’d expect, it’s the extruder which forms the hack here.

A Dremel hot glue gun supplies the hot end, whose mains heater cartridge is replaced with a low voltage one with he help of a piece of brass tube. He already has his own design for an extruder for larger diameters, so he mates this with the hot end. Finally the nozzle is tapped with a thread to fit an airbrush nozzle for printing, and he’s ready tp print. With a much lower temperature and an unheated bed it extrudes, but it takes multiple attempts and several redesigns of the mechanical parts of the extruder before he finally ended up with the plastic shell of the glue gun as part of the assembly.

The last touch is a glue stick magazine that drops new sticks into a funnel on top of the extruder, and it’s printing a Benchy. At this point you might be asking why go to all this effort, but when you consider that there are other interesting materials which are only available in stick form it’s clear that this goes beyond the glue. If you’re up for more hot glue gun oddities meanwhile, in the past we’ve shown you the opposite process to this one.

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An Electric Vehicle Conversion With A Difference

October 30, 2024 by Jenny List 25 Comments

For a first try at an electric vehicle conversion we’re guessing that most would pick a small city car as a base vehicle, or perhaps a Kei van. Not [LiamTronix], who instead chose to do it with an old Ferguson tractor. It might not be the most promising of EV platforms, but as you can see in the video below, it results in a surprisingly practical agricultural vehicle.

A 1950s or 1960s tractor like the Ferguson usually has its engine as a structural member with the bellhousing taking the full strength of the machine and the front axle attached to the front of the block. Thus after he’s extracted the machine from its barn we see him parting engine and gearbox with plenty of support, as it’s a surprisingly hazardous process. These conversions rely upon making a precise plate to mount the motor perfectly in line with the input shaft. We see this process, plus that of making the splined coupler using the center of the old clutch plate. It’s been a while since we last did a clutch alignment, and seeing him using a 3D printed alignment tool we wish we’d had our printer back then.

The motor is surprisingly a DC unit, which he first tests with a 12 V car battery. We see the building of a hefty steel frame to take the place of the engine block in the structure, and then a battery pack that’s beautifully built. The final tractor at the end of the video still has a few additions before it’s finished, but it’s a usable machine we wouldn’t be ashamed to have for small round-the-farm tasks.

Surprisingly there haven’t been as many electric tractors on these pages as you’d expect, though we’ve seen some commercial ones.

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An International Hackerspace Map

October 29, 2024 by Jenny List 17 Comments

If you’re looking for a hackerspace while on your travels, there is more than one website which shows them on a map, and even tells you whether or not they are open. This last feature is powered by SpaceAPI, a standard way for hackerspaces to publish information about themselves, including whether or not they are closed.

Given such a trove of data then it’s hardly surprising that [S3lph] would use it to create a gigantic map of central Europe with lights in the appropriate places (German language, Google Translate link) to show the spaces and their status.

The lights are a set of addressable LEDs and the brain is an ESP32, making this an accessible project for most hackers with the time to assemble it. Unsurprisingly then it’s not the first such map we’ve seen, though it’s considerably more ambitious than the last one. Meanwhile if your hackerspace doesn’t have SpaceAPI yet or you’re simply curious about the whole thing, we took a look at it back in 2021.

Thanks [Dave] for the tip.

Another Commodore Portable We Never (Quite) Received

October 29, 2024 by Jenny List 7 Comments

The story of Commodore computers is one of some truly great machines for their time, and of the truly woeful marketing that arguably spelled their doom. But there’s another Commodore computing story, that of the machines we never received, many of which came close enough to production that they might have made it.

[Old VCR] has the story of one of these, and it’s a portable. It’s not a C64 like the luggable which did emerge, neither is it the legendary LCD portable prototype in the possession of our Hackaday colleague [Bil Herd]. Instead it’s a palmtop branded under licence from Toshiba, and since it’s a rare device even its home country of Japan the article gives us perhaps the only one we’ll ever see with either badge.

The Commodore HHC-4 was announced at Winter CES 1983, and since it was never seen again it’s aroused some curiosity among enthusiasts. The article goes to some lengths to cross-reference the visible features and deduce that it’s in fact a Toshiba Pasopia Mini, a typical palmtop computer of the era with not much in the way of processing power, a small alphanumeric display, and a calculator-style QWERTY keyboard. We’re treated to a teardown of a Toshiba unit and its dock, revealing some uncertainty about which processor architecture lurks in those Toshiba custom chips.

Looking at the magazine reviews and adverts it seems as though Commodore may have had some machines with their branding on even if they never sold them, so there exists the tantalizing possibility of one still lurking forgotten in the possession of a former staffer. We can hope.

If Commodore history interests you, you really should read [Bil]’s autobiographical account of the company in the 1980s.

The Pound ( Or Euro, Or Dollar ) Can Still Be In Your Pocket

October 27, 2024 by Jenny List 85 Comments

A British journalistic trope involves the phrase “The pound in your pocket”, a derisory reference to the 1960s Prime Minister Harold Wilson’s use of it to try to persuade the public that a proposed currency devaluation wouldn’t affect them. Nearly six decades later not so many Brits carry physical pounds in their pockets as electronic transfers have become more prevalent, but the currency remains. So much so that the governor of the Bank of England has had to reassure the world that the pound won’t be replaced by a proposed “Britcoin” cryptocurrency should that be introduced.

Normally matters of monetary policy aren’t within Hackaday’s remit, but since the UK is not the only country to mull over the idea of a tightly regulated cryptocurrency tied to their existing one, there’s a privacy angle to be considered while still steering clear of the fog of cryptocurrency enthusiasts. The problem is that reading the justification for the new digital pound from the Bank of England, it’s very difficult to see much it offers which isn’t already offered by existing cashless payment systems. Meanwhile it offers to them a blank regulatory sheet upon which they can write any new rules they want, and since that inevitably means some of those rules will affect digital privacy in a negative manner, it should be a worry to anyone whose government has considered the idea. Being at pains to tell us that we’ll still be able to see a picture of the King (or a dead President, or a set of bridges) on a bit of paper thus feels like an irrelevance as increasingly few of us handle banknotes much anyway these days. Perhaps that act in itself will now become more of an act of protest. And just when we’d persuaded our hackerspaces to go cashless, too.

Header: Wikitropia, CC BY-SA 3.0.

BNCs For An Old Instrument

October 27, 2024 by Jenny List 5 Comments

Back in the summer our eye was caught by [Jazzy Jane]’s new signal generator, or perhaps we should say her new-to-her signal generator. It’s an Advance E1 from around 1950, and it was particularly interesting from here because it matches the model on the shelf above this bench. She’s back with a new video on the E1, allowing us a further look inside it as she replaces a dead capacitor, gets its audio oscillator working, and upgrades its sockets.

Treating us to a further peek inside the unit, first up is a leaky capacitor. Then a knotty question for old tech enthusiasts, to upgrade or not? The ancient co-ax connectors are out of place on a modern bench, so does originality matter enough to give it a set of BNC sockets? We’d tend to agree; just because we have some adapters for the unit here doesn’t mean it’s convenient. Following on from that is a period variable frequency audio mod which has failed, so out that comes and a little fault-finding is required to get the wiring of the audio transformer.

These instruments are not by any means compact, but they do have the advantage of being exceptionally well-built and above all cheap. We hope readers appreciate videos like the one below the break, and that you’re encouraged not to be scared of diving in to older items like this one to fix them. Meanwhile the first installment is here.

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