I tried to find tour of my high school teacher company (the school itself was owned by Tesla company), but I am not unable to find those, but there is another neat workshop for Nixie tubes: https://www.youtube.com/watch?v=NRYcvzbaRGE
You can get MOSFETs that'll switch 500v for under $2 as well. Check out the irf820, I issued it to drive an fx loop in my amp design.
This changes at extreme power levels. There are few semiconductors that'll transmit in the thousands of watts. Tubes still are used in transmission technology for this reason.
For a concert, its better to have 20-40 amplifiers rather than one big single point of failure (microservices vs mainframe). It's better to lose a few small parts than one big one. When it comes to distribution of source signals, the architectures live engineers are using with aes50/Midas or Dante are pretty danged cool. They just assume component failure is assured.
The video begins with the final product of his labors. This vacuum tube is a triode - it as three elements (or what he terms electrodes): a filament, a grid, and a plate. The elements are inside a glass envelope, which was sealed after evacuation on the top, leaving the little swirl of glass. The wires for the elements (or electrodes) are soldered into the pins of this blue plastic base he has. To me, it looks like the WD-11 vacuum tube of the early 20's, but I think he patterned it on something else.
0:12: Cutting the metal that will become the plate. Heh, odd choice of tool, but whatever works!
0:47: Bending little tabs on the end of the plate material. Later on he is going to wrap this metal on a mandrel into a cylinder, spot weld it closed, then spot weld a little wire to it (both supports it and conducts the electrical current from it). This forms the plate electrode. In this design the filament in mounted vertically in the center of the tube, and all of the elements are mounted concentrically to it, so its usually the outer surface of the plate you see when you look at tubes like this. This design uses the filament as the cathode.
1:58: Making the grid element. This is the element that you vary the voltage on to change the current flowing from filament and plate. He is using a basic helical design, thus the winding of the wire around a small mandrel. The grid is spaced widely to not impede so many of the electrons in the path from the filament to plate - but closely enough that he can still get enough control of that flow when he puts a voltage on the grid. The little loops on the ends of the grid are a nice touch - I don't think I've ever seen that on a real production vacuum tube. The grid wire is much thicker that would otherwise be used in a production tube - BUT, if you do make it with fat wire, it is self supporting and that saves a lot of work in adding in additional supports.
2:19: Making the filament element. It is very much like a incandescent light bulb filament but without the coiled-coil design you see in a typical bulb. He is straightening the filament wire before welding it to the supports. Early tubes used the filament as the cathode and the plate as the anode. Some of these used straight tungsten wire, which you would have to get quite hot to 'boil' off the electrons. Then they figured out that dipping the filaments in metal oxides reduced the temperature you had to heat the filament to. I don't think he did such coating here.
2:59: Now we are cooking with gas...he is beginning the glasswork to construct the envelope. Glass workers can correct me, but I believe he pre-warms the glass, the hits it to melt it enough to allow the tool to flare the end of the tube, then uses the carburizing flame to bring it back down to temperature slowly to prevent it cracking from shock?
4:23: Neat tool for 'cutting' glass tubing. He scores it first, then uses this loop heater to cause the glass to crack through, releasing the part. From here we see some special tooling for turning the flared tube into the base of the envelope, and squishing the end in preparation for the installation of the electrical leads that will pass through it.
6:19: He is assembling the leads for the elements. The wire he welds all of them to is just for support during the later steps. I wonder if the dark areas of the wire are part of a treatment he did to make a good metal-glass seal. Good sealing here is essential - if a microscopic gap opens up when the metal and glass heat up during usage, gas will get into the tube, change its characteristics and given enough of it - ruin the tube entirely.
6:49: Leads are sealed in glass envelope base. Placed into a little oven to anneal/cool slowly.
7:36: Making the body of the envelope. No special seals here, but some nice glasswork in making the rounded end and attaching the evacuation tube.
9:50 - A whole pile of glass tubes. Job well done.
He is welding on the electrodes - first the filament, then the grid is slipped over that, then the plate cylinder, then the support/return for the filament.
0:37: It appears that he is doing a cleaning and surface preparation process here. Oils, organics, fluff, all cleaned away. Everything has to be clean as we move toward sealing and evacuating the vacuum tube.
0:44 - The base and body are joined.
1:20 - The evacuation. not only is he evacuating the tube, he is heating the tube to drive off moisture, gases stuck on the surfaces within the tube. You can really see this at 2:05, where he uses what looks like an RF induction coil to heat the internal elements. The digital display must be the output from some high vacuum gauge. Later on in the video you see some special pumps he has built, but it isn't clear what he used for this tube process. I think the sound in the background is the pumps at work. Perhaps a combo of a roughing pump and mercury pump?
2:15 - Lights up the filament for the first time, all in the effort to get everything besides the elements out of the envelope. Also a check that it keeps heating for an extended period of time and doesn't just fizzle.
2:26 - The sealing operation; a set of flames melts the little tube at the top of the envelope, locking in the vaccum and flavor.
2:58 - This part impressed me the most - he molded his own tube bases. He would have had to selected a material that can hold up to heat well, as the heat from the filaments will conduct right down to the base pins, melt and eventually degrade the plastic surrounding the filament pins.
3:20 - Testing the tubes, using a custom rig to plot curves much like you'd see in tube data sheets.
4:19 - All right, time to use the tubes! first, he has it in a little regenerative receiver, then a CW (for Morse Code) transmitter, then what seems to be a VHF transmitter using a bit of old 450 Ohm transmission line as the tank circuit.
5:01 - Finally the man himself, Claude Paillard, and some of his other work. Love the jacket at the mill.
I wrote to him about how awesome his tube project is and to find out what the heck that music playing in the background was, and he wrote back:
"About the triodes...they have numerous 'children'...in the 2004-2005 8 or 10 were on a very low power transmitter (around 100 milliwatts) with a quartz on 3580 khz...with a lot of 'local' QSO in France. One of these is in the A.W.A museum in Bloomfield N.Y... Around 2009 we go to one watt of RF always Xtal driven, on 3560 kHz...the one on the picture has made more than 300 QSO all over Europe...The last is with a pair of triodes running 5 watts output on 80-40-30-20 meters, with VFO of course...and worldwide received With a careful look, you can identify the 'box' as an old surplus 'BC375 Tuning Unit'
There also others use, but the main project was to return to 'good old time' of our fathers in Ham radio"
Check out his website at http://paillard.claude.free.fr/
making a miniature vacuum tube triode
The Art of Making a Nixie Tube
Scarcity is a problem. No wonder most Western countries rarely have even small boutique production labs these days - the materials and processes involved are (were) highly carcinogenic, and creates a lot of toxic waste pollutants. I keenly follow Dalibor Farny (mentioned elsewhere in this thread) - he seems to have devised a better way to make Nixie tubes (though not tubes like 12AX7s etc. that amplifiers use).
But one wonders, with the current excellence of amp modellers such as the Fractal Axe-FX and the Kemper Profiler etc. whether soon the digital emulation of that analog tube sound will be enough to finally put the last of the tube makers out to pasture?
Not discrediting the market for digital modelers though; most fans of these systems that I know use them for less wear and tear for tours and gigs on their tube counterparts.
EHX buying NewSensor's factory ensures that tubes will be around for decades, even for this niche market. Plus the NOS market is still one any laymen can participate in.
I do think audiophiles trump musicians when it comes to superstitions. Just recently found out there’s a market for cables costing hundreds of euro’s to interface hi-fi components, with lush descriptions of the soundstage afforded by such cables. Ignoring the fact any record one listens to will have its sound passed through 20 euro cables at some point in its production.
I'm hoping these blokes never crack open the amp to look at the plain old PVC-insulated wiring within. And don't tell them the oil-in-paper caps are fading over time. Ditto with the carbon resistors.
Meanwhile, humidity of the air and barometric pressure has a measurable affect on the sound of paper-cone speakers. How long before an "audiophile" barometric chamber is marketed?
I can see something like this being a part of the audiophile attraction to these types of components: that every time the owner adds a new set of magic interconnect cables, magic power cables, or whatever, they imaging that they hear an improvement. In the end, they have a lot of themselves invested in their "rig", as they call them, and so find it easy to hear virtues that aren't really there.
The weakest link always has an effect, as you mention. To some musicians, this is the effect. I.E. Hendrix preferring cheap coily-cables which rolled off the high-end on his Strat/Marshall combination nicely. Now coil cables are a premium.
Electric guitarists are often poor, clever, and self reliant. They can regularly find themselves out in the boonies with nothing but duct tape and baling twine to hold their rig together. Choosing a more robustly built older amp is not an irrational choice for such a person.
Audiophiles... I don't understand why you want tube amps. They are good for guitar players because of their imperfections (e.g. overdrive, "warmth", etc) which is the last thing I want when I'm listening to a quality recording.
It might be possible, but it surely isn't easy nor obvious. "Instantly," as you claim? Sorry, but I'd bet a sizeable stack of money that's not the case. Perhaps if you're talking about a 20-year-old 1st generation Line 6 Pod or Yamaha Fx500, then okay, I can see that. But modern modeling amps are exceedingly good at reproducing the nuances of a valve amp. The Kempler is remarkable -- I would go as far as to say astounding -- in its ability to reproduce the breakup, compression, warmth etc. of an amp at all volume levels. If you heard one in person you'd be a believer. At the other end of the spectrum, even a $150 Fender Mustang amps does a respectable job of sounding faithful [disclaimer - the factory settings are pure rubbish and almost embarrassingly poor, but tweak the settings in the computer editor and a whole wealth of sounds are available, some of them are brilliant).
And why would someone want a valve amp for playback of recordings? The same reason you claim to hear the "warmth" of a valve guitar amp. The same reason guitarists use an EP3 (echoplex tape delay) with the tape out -- that preamp circuit compresses, clips, and enhances the waveform in a way that is very pleasing to the ear. Some notes increase in clarity and bloom in a pleasant way.
A valve amp doesn't imply distortion. Leo Fender was a radio tech before forming his amplifier/instrument company. He knew the value of having lots of headroom.
The key is blind testing. Everyone thinks that they can tell the difference between a Kemper and a valve amp.
I've posted many threads over the years at TheGearPage, with real amp recordings vs hardware/software modellers, and in nearly all cases, the guesses are just that - guesses, which fall into a 50/50 distribution. That is of course, when the guys who are purported 'experts' actually participate in the polls. Most of them tend to disappear whenever they are challenged to voice in on them.
I have some lovely tube amps here, and I also own a couple of Axe-FX's, and for me, when travelling, the Axe-FX is my 'go to' purely for convenience. At gig volumes, and in a band mix, it is pretty hard for me to tell the difference, and I enjoy the tone the same.
I know a lot of guitarists say that they have to have the 'feel', but for me, the 'feel' is there anyway (I usually feed my Axe-FX through the power amp stage of a real amp). I normally play fairly clean, blues/rock based stuff, and the last gig I flew across the country for, the rented backline actually had a Mesa Rectifier III for me. I've never played a Rectifier style amp before, but I had my Axe-FX, with a Fender Bassman amp model preset, through the power amp stage of the Rectifier, and it sounded amazing. The other bands were asking me how I was getting such crystal clean tones out of a 'metal' amp!
The ode to the way things used to be I think drives this market. Combine that with vinyl and you have a medium and listening experience that's superseded entirely.
If you're interested in this sort of thing, I found other similar videos by another unique individual, here : https://www.youtube.com/user/glasslinger/videos
CW Was CQ DE _ . _ . _ _ . _ _ .. .
(Seek You from) normally a call sign would follow
It does make me reconsider the value of several boxes of older vacuum tubes I have upstairs in storage, thanks to my father-in-law - I would probably best be served by going through first them before discarding...
No one uses mercury any more as a working fluid in the pump. you use vacuum rated oil instead. And he's definitely using mercury. Also looks like a two stage piston pump. And mostly people use liquid ring vacuum pumps as roughing pumps.
Difficulty the roughing pump only gets you to a few microns at best. Good enough for neon work. But tubes require a hard vacuum. Need a diffusion pump (hot oil vapor) or turbo molecular pump (ultra high speed 'fan') after the roughing pump.
I don't think he's using a diffusion pump or turbo molecular pump.
It seems he made all the specialized equipment he needed to make the tubes.