Slashdot is powered by your submissions, so send in your scoop

 


Forgot your password?
Close
typodupeerror
×
Hardware Hacking Build

Hand-Made Vacuum Tubes 227

Posted by kdawson from the doesn't-suck dept.
djmoore writes "Over at Make Magazine, watch this video of a French amateur radio operator making and testing his own vacuum tubes. It looks like he built much of his own equipment as well. The Make poster notes: 'I love the ease with which he performs these rather high-end skills (like glass forming), the gestural flourishes (like it's hand magic), and the Zelig-esque soundtrack.'"
This discussion has been archived. No new comments can be posted.

Hand-Made Vacuum Tubes More

Hand-Made Vacuum Tubes

Comments Filter:

  • reason (Score:5, Funny)

    by User 956 ( 568564 ) on Tuesday January 08, 2008 @07:21PM (#21962272) Homepage
    Over at Make Magazine, watch this video of a French amateur radio operator making and testing his own vacuum tubes.

    This was covered in Make Magazine, primarily because Nature abhors a vacuum.

    • are you saying (Score:4, Funny)

      by Bananatree3 ( 872975 ) on Tuesday January 08, 2008 @07:25PM (#21962324)
      Make Magazine sucks? How dare you!

    • Yeah, well (Score:5, Funny)

      by EmbeddedJanitor ( 597831 ) on Tuesday January 08, 2008 @07:25PM (#21962330)
      Make will rectify that!

    • Re:"French amateur radio operator" (Score:5, Informative)

      by Anonymous Coward on Tuesday January 08, 2008 @07:40PM (#21962532)
      Neither Make nor Slashdot have the basic decency to name the man: Claude Paillard.

      What is it with acting like foreign nationals are some sort of trained monkey? C'mon folks.

      Anyway, here's a direct link to his site so you can skip the non-article at Make. Site includes much information (use the fish as needed), the streaming dailymotion vid, and a download link for those who can't see streams. Enjoy.
      http://paillard.claude.free.fr/ [claude.free.fr]

      Thanks Claude! That rocks.

    • Re: (Score:2, Funny)

      by eclectro ( 227083 )
      Quite honestly, this guy has nothing on me. I'm building a space shuttle out of disposable razors!

  • The art of electronics (Score:5, Insightful)

    by Bananatree3 ( 872975 ) on Tuesday January 08, 2008 @07:27PM (#21962364)
    This guy isn't just a tinkerer, but an artist as well. This kind of thing is an art as much as it is a science.

    • Re:The art of electronics (Score:5, Interesting)

      by User 956 ( 568564 ) on Tuesday January 08, 2008 @07:33PM (#21962438) Homepage
      Yeah, like Pierre Scerri, who spent 15 years making a scale model of a Ferrari 312. [techeblog.com] Not only did he make the body, he learned to make glass in order to create the headlights, and learned to make rubber to make his own tires. It's almost unbelievable.

      • Re:The art of electronics (Score:4, Interesting)

        by ivan256 ( 17499 ) on Tuesday January 08, 2008 @07:54PM (#21962710)
        I can respect having an obsessive hobby. Especially when it produces such spectacular results.

        However, if you're going to spend that much time, why not build a full size vehicle so you can actually drive it?

        • Re:The art of electronics (Score:5, Interesting)

          by RDW ( 41497 ) on Tuesday January 08, 2008 @08:18PM (#21962966)
          'I can respect having an obsessive hobby. Especially when it produces such spectacular results.'

          Though with some people, this sort of thing can get just a bit _too_ obsessive:

          http://www.sandia.gov/LabNews/LN02-13-98/cherry_story.html [sandia.gov]

          'The switch mechanisms Kaczynski used were hand-made switches that he would spend weeks building...He machined his own screws.'

      • Re: (Score:3, Insightful)

        by Frogbert ( 589961 )
        That's all well and good but after 15 years and your done wouldn't you think to yourself... Damn I should have made a full scale replica.
  • While vacumn tubes are strictly in the realm of hobbyists and zealous audiophiles, nevertheless it is important for teens and young adults to understand where the electronics industry started from. They're already made to study what can argueably be considered useless information, so why not study something that is cool and informative as well? Think of it as shop class for nerds.

    • Re: (Score:2, Insightful)

      by kidsizedcoffin ( 1197209 )
      For better or not, you don't need to be a zealous audiophile to appreciate the sound of a tube guitar amp.
      • Just about every serious guitarist still uses tube amps. They're not esoteric or ancient at all for this purpose, because they're the best tool for the job. Although digital models of tube amps have improved, nothing sounds quite like the real thing.

    • Re:We need this type of thing done in the classroo (Score:4, Insightful)

      by crosson ( 1204404 ) on Tuesday January 08, 2008 @07:54PM (#21962708)
      Why do you have to see everything through the category useful/useless? Is it so hard for you to imagine that one day, let's say in the next 1000's of years, we will need a guy who can make vacuum tubes? It's never good for any technologies to be lost, even if they seem too old to be useful now.
    • No end of projects if you want to go old school. If you get your glass blowing down, you can make a mercury arc rectifier! Its all good right up until the part about the 2kg of mercury needed to "make it happen". Also, the voltages and currents tend to be a bit high. Great to look at! Just don't breath the vapour that leeches out.

    • While vacumn tubes are strictly in the realm of hobbyists and zealous audiophiles, nevertheless it is important for teens and young adults to understand where the electronics industry started from.

      I'm all in favor of broad knowledge, but really, what *possible* lesson does someone learn from knowing about vacuum tubes? Talk about an esoteric subject!

      There really are a limited number of hours in the classroom, and too many subjects are given short shrift as it is. My pet peeve is that schools don't tea

      • Re:We need this type of thing done in the classroo (Score:5, Insightful)

        by Clueless Moron ( 548336 ) on Tuesday January 08, 2008 @08:54PM (#21963338)

        You can learn a hell of a lot from vacuum tubes! They are far easier to understand than transistors.

        There's a reason why they're called "valves" in the UK. It's like a valve controlling a powerful stream of water; a small change on the valve leads to a very large change of current. That change in current can, in turn, control a much bigger valve that controls an even larger current.

        In this case, the "valve" is a control grid (that spiral thing) surrounding the cathode (the thin hot wire in the middle). The big cylinder is the "plate". The cathode itself has a cloud of electrons around it (because it's hot), and a small signal on the grid controls how much of that can scoot across to the plate (which is positively charged due to a power supply putting a strong positive voltage on it). So a weak sine wave signal on the plate will lead to a big sine wave current from the plate.

        There, now you know the basics of amplification (although I skipped some details). I couldn't have done it by describing a BJT (transistor), because they're far weirder.

        • Re: (Score:3, Insightful)

          by Reality Master 101 ( 179095 )

          You can learn a hell of a lot from vacuum tubes! They are far easier to understand than transistors.

          For someone studying electronics, I agree. But as a general subject? Why not teach the theory on how they used to slop pigs 100 years ago? Or the techniques for cutting hair? Or pick your esoteric piece of knowledge that is utterly useless to 99% of students.

          • Comment removed based on user account deletion
          • As an electrical engineer - hell yes, they should be taught. Probably not in-depth like transistors, but as a technology, the basics should at least be covered. I also happen to be somewhat of an amateur historian of electrical power systems, and there's a lot many of my fellow EE students could have learned from some amazingly old stuff. Simple and elegant are two concepts often lost on them, but not on the clever EEs of the late 1800s / early 1900s. I'm not saying that we should go back to using rotar
        • I couldn't have done it by describing a BJT (transistor), because they're far weirder.


          To make bipolar simpler, they are simply a current amplifier, not a voltage amplifier. Think power steering. You push some, the force is boosted in proportion to the push you provide. The low voltage current needed to drive them instead of a high impedance voltage is why much bi-polar stuff is low impedance.
      • I'd disagree. See the computer science article below! Schools have fallen into the rut of teaching technology by rote.. and not by experience. Heck if CS students brushed up on their binary, they could MAKE a computer from what he's doing!!! True, it's not useful by itself by today's standard, but the Experience of doing it all from scratch would be fantastic!!!

        • Re: (Score:2)

          by leenks ( 906881 )
          In the UK this is due to league tables. Why teach kids how to do something for the rest of their lives if they might end up messing up in a known-format test? Bad results in that test result in the school being shunned by parents, even as far as moving their kids to other schools, sending the schools into "special measures" and ultimately affecting salaries and teacher motivation.

          No, it's much better to teach the kids how to pass the tests and only the tests. That way the parents are happy because little Jo
    • there are places where vacuum tubes are still used, some radio stations use them in their transmitters, i was once inside the local AM radio station in my home town and the vacuum tube was as big in circumference as a dinner plate and about 18 inches tall, so there still is some commercial/professional demand for them...
      • yeah because solid state components that can handle the power and frequency involved in a big radio transmitter are even more expensive than vacuum tubes that can.

    • Re: (Score:2)

      by KC1P ( 907742 )
      No kidding, it's like assembly language for hardware! Even if people were making transistors at home (are they? hmmmmm), there wouldn't be much to see, so tubes are cool because the magical theoretical guts that you read about in books are right there for you to see inside a glass bubble.

      Well, except for the parts that are silvered over (in commercial tubes) that is -- huh, I wonder if that means the home-made tubes are leaking radiation all over the place. Still worth it though (but to be on the safe si

      • Re:We need this type of thing done in the classroo (Score:4, Informative)

        by Anonymous Coward on Tuesday January 08, 2008 @08:25PM (#21963026)
        The silvering has nothing to do with radiation. It is a thin coating of reactive metal to take up any oxygen left in the tube after it has been sealed. If you ever find an old tube where the silver patch has gone white, it is gassy and will not work properly. (It may work to some degree but is also likely to have a strange glow from ionising the gas. Depends how much gas has leaked in.)

        You do get X-rays from tubes working at high voltages, but they are of pretty low energy in typical applications and probably don't make it out through the glass. TV tubes use leaded glass to reduce the X-radiation.

        • Re: (Score:2)

          by Sanat ( 702 )
          Please mod up comment by the parent. It is right on.

          As an addition...
          When vacuum tubes were used in computers the defective tubes would often have a blue glow indicating a gassy condition and those were changed out first.

      • Re: (Score:3, Informative)

        by Linker3000 ( 626634 )
        The 'silvering' in most tubes isn't a screen but is caused by a process called 'gettering' where a small amount of a magnesium or calcium-based compound is burnt off (evaporated) by an external induction coil as part of the final manufacturing process. As the valve is 'gettered', the magnesium/calcium 'cleans out' any small traces of gas left in the envelope.

    • Even teaching basic semiconductor stuff is simple.

      My kids and I built a crystal set and made a cats whisker diode for it using some brass sheet, wire and a lump of galena (from the mineral & crystal shop). Also made a diode with a rusty razor blade and another with a lump of silicon. These didn't work as well as shop germanium diodes, but they still worked. Made our own variable capacitors using paper and tin foil too.

      You can even build simple amplifiers etc using tunnel diodes: http://home.earthlink.ne [earthlink.net]

      • Re: (Score:2)

        by flajann ( 658201 )
        Ah, tunnel diodes! I loved playing with them when I was a kid! Brings back some fond memories...
    • It will also serve to bring us back after the collapse of society and technology.

      Id like to see you make semiconductor based transistors in your basement.

      • Semiconductors never could have been made without (Score:5, Informative)

        by Ellis D. Tripp ( 755736 ) on Tuesday January 08, 2008 @08:39PM (#21963182) Homepage
        vacuum tubes.

        Once you get beyond the crude PN junction diode (like a galena crystal), making transistors and such requires ridiculously pure germanium and/or silicon. These materials are purified by a process called "zone refining" which uses induction heating to melt the semiconductor materials at incredibly high temperatures. Induction heating in turn requires many kilowatts of radio frequency power, which is exactly the type of application where vacuum tubes are still widely used even today.

      • It will also serve to bring us back after the collapse of society and technology. Id like to see you make semiconductor based transistors in your basement.

        You aren't going to make [useful] vacuum tubes in your basement without considerable technological support either.

    • Not just them. (Score:4, Interesting)

      by jd ( 1658 ) <imipak@ y a hoo.com> on Tuesday January 08, 2008 @08:25PM (#21963028) Homepage Journal
      Thermionic valves have vastly superior tolerance to electromagnetic radiation, acceleration, shocks, and other hostile conditions. The power they can push through is astonishing. On the flip-side, their mean time between failures isn't always so great, they're bulkier, they use more power, and it can be very hard to find some of the older lines.

      If you wanted to build some part of an embedded device that absolutely had to take some really ugly conditions, you could do a whole lot worse than to build that specific module using valves. Let's say you wanted to build a new module for the IIS, for example. The internal circuits can largely be protected, so conventional radiation-proof chips would be fine. However, if you wanted reliable computing elements that could be strapped to the outside of the pod, you've harsh conditions indeed. Lead-smothered rad-hardened silicon chips that can handle space tolerances and have their own heating elements would probably work. Lots of things that can go wrong, though. Complexity-wise and weight-wise you're probably not significantly better off than using thermionic valves with none of the extras.

      Where else could valves be used? Easy. If the cathode and anode are deliberately mis-aligned, then one or more grids must be set to a value such that the directed power completes the circuit. If something goes wrong (too much power, something fails, whatever), then the beam is either not pushed at all or pushed far too far. In either case, you've an all-electronic circuit-breaker - ideal if you want to get rid of fuseboxes and mechanical trip-switches.

    • The company I work for makes an RF power delivery system that uses them, and they are still used in broadcast amplifiers. There's still a need to teach about vacuum tube circuits for other than hobbyist applications.

    • "Sometimes you need to reinvent the wheel... (Score:4, Insightful)

      by ciaohound ( 118419 ) on Tuesday January 08, 2008 @09:36PM (#21963740)
      not because you need wheels, but because you need inventors." Not sure who first said that.
    • While vacumn tubes are strictly in the realm of hobbyists and zealous audiophiles...

      Almost all modern guitar amplifiers are valve-powered.
    • We did it in 1993 in a junior level physics lab class at the University of New Mexico.

      John Panitz was the prof teaching it, and I was his TA for the class. We took them through basic metal forming, vacuum technology, glass blowing, molding a plastic, etc.

      The tubes were a bit different, as the students modified them during the semester and they needed to be opened repeatedly. We used Torr Seal to mold a base for them and used an o-ring seal between it and the glass envelope (we kept them attached to a runnin
    • it may be so at this particular point. however, vacuum tubes are, contrarily to transistors, impervious to the effects of EMP generated by an atomic weapon.

      if some dumbass ever decides to fsck the world up, you can say goodbye to that core 2 duo...

      the vacuum tube radio set will continue to chug along fine however

  • The next logical step... (Score:5, Funny)

    by bubbl07 ( 777082 ) on Tuesday January 08, 2008 @07:35PM (#21962470) Homepage
    Perhaps we can use these hand-made tubes to make a new hand-made internets! Think of the possibilities!

  • First Thought... MEVs (Score:4, Interesting)

    by davidsyes ( 765062 ) on Tuesday January 08, 2008 @07:45PM (#21962608) Homepage Journal
    Not Million Electron Volts, but

    "Male Enhancer Volume System Product"

    How much juice/oomph can YOUR tubes deliver?
  • did i see him transmitting CW on 14.524? in the USA i know the top limit on the 20 meter band is 14.350, not sure about France, someone with that much talent and skills can do whatver the they want (Kudos!) that is some remarkable craftsmanship...

  • Upping the coolness factor (Score:5, Interesting)

    by autophile ( 640621 ) on Tuesday January 08, 2008 @07:57PM (#21962748)

    The only thing that would make this cooler is if he made his own Nixie tubes!

    I thought there were issues not addressed clearly in the video. First, I thought I learned in college chemistry (now rummaging in decades-old longterm storage media) that one of the big problems was getting a good seal of glass around metal, which wasn't solved until they put together the right glass with the right metal.

    Also, aren't the electrodes in a vacuum tube coated with something to prevent early breakdown? And isn't there some chemical you have to put inside the tube to absorb the gas given off when electrons smash into the electrodes? So while this is incredibly neat-looking, I don't think the tubes would last very long...

    --Rob

    • Glass/Metal seals... (Score:5, Informative)

      by Ellis D. Tripp ( 755736 ) on Tuesday January 08, 2008 @08:25PM (#21963022) Homepage
      If you look closely at the wires he is sealing into the glass "press", you will see a short reddish-brown section. This is most likely "dumet", or copper coated nickel/iron. This material is specially designed to have the same coefficient of thermal expansion as glass, and was used as the sealing material in most receiving tubes. The copper coating forms an oxide layer that dissolves into the glass, creating a vacuum-tight seal.

      Before the development of dumet, kovar, and other specialized alloys, the seals in very early tubes were made using platinum wire. Cost considerations brought this to a quick end, as soon as cheaper suitable materials were developed.

      The electrodes in later tubes were often coated with various materials to aid heat dissipation or reduce secondary electron emission. Early tubes that were similar in construction to what is being made here generally used plain metal grids and plates.

      Most tubes contained a "getter" made of barium or other reactive metal, to adsorb any gas molecules which survived initial pumpdown, or which were liberated from the internal elements during operation.

      • Most tubes contained a "getter" made of barium or other reactive metal, to adsorb any gas molecules which survived initial pumpdown, or which were liberated from the internal elements during operation.

        I wondered why he seemed to power up the filament until it glowed white hot like an incendescent lamp, while pumping the air out. I guess he must have been trying to sacrifice a little of the filament's metal to help burn off the last remaining oxygen that the pumpdown can't get out.

        • Re:Getter (Score:5, Interesting)

          by Ellis D. Tripp ( 755736 ) on Tuesday January 08, 2008 @10:36PM (#21964252) Homepage
          He was superheating the entire structure to drive out occluded gases from the metal components. During this operation, the entire tube was surrounded by a coil driven by an induction heater, which was heating the plate and grid red hot, as well. All this takes place while the tube is attached to the vacuum pump, prior to sealoff.

          I am not sure what material he was using for his filament wire, but if it was thoriated tungsten, then the "hot shot" cycle also serves to build up a surface layer of thorium oxide on the filament, and reduce it to metallic thorium. Thorium has a much lower work function than pure tungsten, and will emit electrons efficiently at a much lower operating temperature.

          Yes, I am a tube geek...:) Years ago, I made a much cruder triode in a peanut butter jar as a HS physics project.
          • The thorium was what I was wondering about too....

            When I took an interest in tube audio some years back, I asked why people didn't make their own tubes, and the problem of obtaining {or of home-manufacturing} thoriated tungsten filaments was the reason given. Without Thorium, the filaments don't last very long at typical power levels--and Thorium (at least, of the type needed) was pretty toxic, and quite radioactive besides.

            Lots of people (online) had built their own transformers--but I didn't hear fro

        • you might have noticed the plate red hot in a coil (Score:5, Interesting)

          by swschrad ( 312009 ) on Tuesday January 08, 2008 @10:56PM (#21964388) Homepage Journal
          "refining" a tube typically meant heating it up in an inductive system to burn out impurities and gas in the tube elements, and filaments may or may not also be heated up at that time. typically were. getters are often "flashed" with a high voltage impressed on them during this period to be sure the impurities are fully absorbed and can't get back into the tube metals and glass spacers.

          many getters at the period in which that tube type he's duplicating used phosphorus. not as efficient as aluminum and barium, but easier to flash over. WWI, remember, you couldn't pull much vacuum. the getter had to do the job. so old tubes had funny colors inside from the getter flashover.

    • State of the Art (Score:5, Informative)

      by localroger ( 258128 ) on Tuesday January 08, 2008 @08:31PM (#21963088) Homepage
      Limping through the writeup with what's left of my high school French I get the idea that he's not just making homemade tubes, he's duplicating a particular class of historic tubes which were common around WWI. He's using authentic techniques. These tubes were handmade at great expense because they were used for maritime communication where price was no object, and modern standards of longetivity didn't apply; if such a tube lasted 500 hours it was doing great. Also, some of those tubes had soft vacuum so an imperfect seal wasn't such a big deal.

      I do have to say this is one of the most impressive projects of its type I've ever seen; it's clearly a labor of both love and skill.

    • he does seem to dip the electrode assembly in several pots after manufacture. I can't read what it says on the pots though as it's in french.

      As for right metal/right glass I presume that is just a matter of buying the right materials.
      • I haven't done much reading, writing, or speaking in French for about 13 years, but I can pick out a couple. To the far left in front is apparently acetone. The last one on the right in front is either "acide chloridrique" or "acide chlorhydrique", which would be either chloric acid or hydrochloric acid.

        The one labeled "eau ..." is water of some sort ("eau" being "water"), but I'm having trouble picking out just what sort. The label wraps around and looks like the adjective starts with "denin", but maybe

    • So while this is incredibly neat-looking, I don't think the tubes would last very long...
      What makes you think that those issues haven't been dealt with? Just because you couldn't tell how they were dealt with from the video?

  • He not only made the tube, (Score:5, Informative)

    by Toinou ( 1059440 ) on Tuesday January 08, 2008 @08:06PM (#21962834)
    he also made all the necessary equipment, like vacuum pump. If you are interested in tubes, he says the "musée des arts et métiers" is a reference. This is an engeneering museum in Paris, which has an incredible collection. When I go there, I stay for hours. Do not mistake it with the science, the nature science, or the technology museum (which are also quite interesting).

    • Re: (Score:2)

      by dido ( 9125 )

      Is that the museum where we see Casaubon hiding at the beginning of Umberto Eco's Foucault's Pendulum? Where the TRES have their rite?

      • I believe it is, but it's been a long time since I last visited or read that book.

      • Re: (Score:2)

        by fsmunoz ( 267297 )

        Is that the museum where we see Casaubon hiding at the beginning of Umberto Eco's Foucault's Pendulum? Where the TRES have their rite?

        It is; it's were in the beginning the young couple is discussing the Pendulum experiment in rather cold terms, and where TRES makes the final rite with Belbo... I have found this link [culture.fr] amongst others, wich both mentiones the pendulum an a "Découvre le béton" workshop... something aking to the "Amazing History of Metals". Coincidence? Ha!

        Great catch by the way.

  • I'll Out-Retro You (Score:4, Funny)

    by Tablizer ( 95088 ) on Tuesday January 08, 2008 @08:11PM (#21962886) Journal
    Oh yeah? Well, I built a wheel out of popcicle sticks!
  • very cool

    i have two old shortwaves that i'd love to get working again.

  • yay! (Score:2, Funny)

    by Elsapotk421 ( 1097205 )
    maybe now I can make my own interwebs!
  • Large medium wave radio transmitters still use thermionic valves in their output stages. Solid state electronics have trouble handling megawatt power levels.

  • Vacuum tubes were pretty much ALL hand-made.... (Score:5, Interesting)

    by Ellis D. Tripp ( 755736 ) on Wednesday January 09, 2008 @12:02AM (#21964886) Homepage
    , as sophisticated robotics didn't yet exist. The most sophisticated part of tube making, the assembly of the internal components or "mount" was done largely by hand, usually by rows and rows of women (smaller fingers) hunched over microscopes in dust-free rooms.

    Once the mounts were assembled and welded onto the stems, the sealing into bulb and pumping down was somewhat automated. Done on a machine called a "sealex", the mounts would be inserted into bulbs, sealed in place, evacuated, heated to activate the cathodes, sealed off, and getters flashed, with each operation taking place at a different "station" on the sealex.

    An interesting photo essay on the construction of the famous 300B audio triode is available here:

    http://www.westernelectric.com/history/tour01.html [westernelectric.com]

    • No, tube manufacture was mechanized by the 1950s. You're looking at an outfit that makes tubes that sell for $600 each, for sale to audio nuts. Here's a 1952 article on a CRT assembly line. [thevalvepage.com] Vacuum tubes were made on machinery similar to that used to make light bulbs.

      • The article talks at great length about the manufacture of the CRT bulbs, and the exhaust process, both of which were easily automated, even back then. I talked about the automated "sealex" machines in my last post.

        But the heart of the CRT, the electron gun, with it's tiny metal components, was still hand assembled, by operators using microscopes and tiny resistance spot welders. Just the same as standard receiving tubes. The final assembly and evacuation lent itself to automation, but the intricate assembl

  • I'm impressed (Score:5, Funny)

    by s_p_oneil ( 795792 ) on Wednesday January 09, 2008 @12:30AM (#21965046) Homepage
    He actually found a use for those tiny scissors that come with a Swiss Army Knife.

Slashdot Top Deals

I have hardly ever known a mathematician who was capable of reasoning. -- Plato

Close