The vacuum tube is largely ignored in modern electronic design, save for a few audio applications such as guitar and headphone amps. The transistor is smaller, cheaper, and inordinately easier to manufacture. By comparison, showing us just how much goes into the manufacture of a tube, [glasslinger] decided to make a wire-element pilotron – from scratch!
To say this is an involved build is an understatement. Simply creating the glass tube itself takes significant time and skill. [glasslinger] shows off the skills of a master, however – steadily working through the initial construction, before showing off advanced techniques necessary to seal in electrodes, produce the delicate wire grid, and finally pull vacuum and seal the tube completely.
The project video is an hour long, and no detail is skipped. From 2% thoriated tungsten wire to annealing torches and grades of glass, it’s all there. It’s enough that an amateur could reproduce the results, given enough attempts and a complete shop of glassworking equipment.
The pilotron may be a forgotten design, but in 2018 it once again gets its day in the sun. Overall, it’s a testament to [glasslinger]’s skill and ability to be able to produce such a device that not only looks the part, but is fully functional on an electronic level, as well.
There’s a few people out there still building valves the old fashioned way, and we’d love to see more – tip ’em if you got ’em. Video after the break.
[Thanks to Morris for the tip!]
Continue reading “How To Make A Pilotron, The Forgotten Tube”
It all began with a cheap Chinese rotary vane vacuum pump and a desire to learn the witchcraft of DIY vacuum tubes. It ended with a string of successes – a working vacuum chamber, light bulbs, glow tubes, diodes, and eventually this homebrew power triode and the audio amplifier built around it.
[Simplifier]’s workshop seems like a pretty cool place. It must have a bit of an early 20th-century vibe, like the shop that [John Fleming] used for his early work on vacuum tubes. Glass work, metal work, electronics – looks like [Simplifier] has a little bit of everything going on. True to his handle, once [Simplifier] had a cheap but effective vacuum rig he started with the easiest projects – incandescent and gas discharge lamps. Satisfied that he could make solid electrical and physical connections and evacuate the tubes, he moved on to diodes and eventually triodes. The quality of the tubes is pretty impressive – stray gasses are removed with a bake-out oven and induction-heated titanium getters. And the performance is pretty solid, as the video below reveals.
Very impressive overall, and it’s not just the fact that he’s building tubes from scratch – we’ve seen that before. What shines here is that specialized equipment is not needed to make working and reliable tubes – just a MAPP torch, simple hand tools, and a low-end vacuum rig. Anybody could – and probably should – give this a try.
Continue reading “Home Brew Vacuum Tubes Are Easier Than You Think”
Today we are quite excited to announce HANDMADE.hackaday. HANDMADE is a place where we celebrate craftsmanship. Usually in the form of a stunning video, or a beautiful image gallery. We will also be sharing extremely detailed DIY projects as well as tutorials. Hop on over and take a peek for yourself to see what you’re in for, but be prepared to clear your schedule, you’re not leaving any time soon.
We are also producing some videos of our own for this that we hope you’ll like.
A personal note:
I am personally so excited about HANDMADE. I’ve been wanting to put this together for a very very long time. I eagerly consume every video of this nature I stumble across, often putting them full screen, high def, and putting in headphones. Any of you who know me personally will attest that getting my full attention on any single thing ever is a daunting task. Also note that these videos usually last several entire minutes; a lifetime in my attention span.
Watching people make things, while applying a practiced and refined skill is almost a religious experience for me. This is creation. I hope some of you will enjoy this area as much as I do.
We’ve seen homemade x-ray devices and we’ve seen people making vacuum tubes at home. We’ve never seen anyone make their own x-ray tube, though, and it’s doubtful we’ll ever see the skill and craftsmanship that went into this build again.
An x-ray tube is a simple device; a cathode emits electrons that strike a tungsten anode that emits x-rays. Most x-ray tubes, though, are relatively large with low-power mammography tubes being a few inches in diameter and about 6 inches long. In his amazing 45-minute-long video, [glasslinger] shows us how to make a miniature vacuum tube, a half-inch in diameter and only about four inches long.
For those of you who love glass lathes, tiny handheld spot welders and induction heaters, but don’t want your workshop bathed in x-rays, [glasslinger] has also built a few other vacuum tubes, including a winking cat Nixie tube. This alternate cat’s eye tube was actually sealed with JB Weld, an interesting technique if you’d ever like to make a real home made tube amp.
For the Milan design week held last April, [Patrick Stevenson Keating] made a cathode ray tube and exhibited it in a department store.
The glass envelope of [Keating]’s tube is a very thick hand-blown piece of glass. After coating the inside of the tube with a phosphorescent lining, [Keating] installed an electrode in a rubber plug and evacuated all the air out of the tube. When 45,000 Volts is applied to the electrode, a brilliant purple glow fills the tube and illuminates the phosphor.
Since the days of our grandfathers, CRTs have usually been made out of thick leaded glass. The reasoning behind this – and why your old computer monitor weighed a ton – is that electron guns can give off a substantial amount of x-rays. This usually isn’t much of a problem for simple devices such as a Crookes tube and monochrome CRTs. Even though [Keating] doesn’t give us any indication of what is being emitted from his tube, we’re fairly confident it’s safe for short-term exposure.
Despite being a one-pixel CRT, we can imagine using the same process to make a few very interesting pieces of hardware. The Magic Eye tube found in a few exceptionally high-end radios and televisions of the 40s, 50s, and 60s could be replicated using the same processes. Alternatively, this CRT could be used as a Williams tube and serve as a few bits of RAM in a homebrew computer.
You can check out the tube in action while on display after the break, along with a very nice video showing off the construction.
Continue reading “Building a CRT and bathing yourself in x-rays”