Tube Kickstarter Program

[calexanian]

A little update..



Kinda ugly looking seal, but I have not used a glass lathe in quite a while and it is soft glass which is very hard to work with when you don't have an annealing oven. I am just testing the Moly ribbon as a filament. Its coated with triple carbonate and the anode is just a flag of nickel.



Sealed and getter flashed. The filament appeared to activate properly. I ran it up to 4 amps current which was near yellow heat. That was a little hot for activation. Its typically done at bright orange or flaking can occur. Red/Orange and uniform heating was reached at 3 amps filament current with an Eb/Ib of up to 25ma at 100 volts. there is 2 inches of filament. Its down quite a bit from nickel with reducing agents but for just a pure base metal that is not bad. It is a bit gassy. At over 100 volts there is a definite gas current but it does not avalanche so the getter may sorption the rest over night. Since the anode was just a flag I could not heat it very well with RF bombardment and it will most likely outgas badly. I will make a cylindrical anode next time so I can outgas it more throughly. Also I did not have the Diffusion pump in the system and sealed at about 20 micron. That was normal in receiving tube production to seal that high in pressure but the parts were made to outgas quickly through bombardment and the glass was still screaming hot from sealing ensuring the evolution of gas post sealing would be low. Also my home made gland fitting did not have the proper O ring in it hence the tube of vacuum grease. Under dead head that pump should get down to 5 micron or even less so I had a very small leak in the gland o ring.

[N2IXK]

VERY cool!  Any chance of plotting and sharing some curves from that tube?

Years ago, I built a VERY crude triode in a peanut butter jar as a high school physics class project. Unfortunately, between the seals through the metal lid and the limitations of the available vacuum pump, we were never able to achieve a hard enough vacuum to get it acting as more than a thyratron....

[calexanian]

Its just a diode. the Eb/Ib runs up to 100 volts at which point it begins to ionize. Since the anode is just a flag of nickel I was not able to outgas it completely. Monday i will make another with a cylindrical anode to allow better out gassing. That is using a .001 X .05 moly filament about 2.5 inches long. Pure moly so there is no reducing chemical in it. That was coated in triple carbonate. I reached a peak emission of 25ma which for just pure moly as a base metal is not bad. I have some real deal nickel/cobalt with a touch of chrome filaments that I know are really good. They are actually filaments for 596 rectifiers which are the same as 5R4's. When I get my system all in shape i will start playing with those. Until then I don't want to waste them. Plenty of experimenting to do for the time being with moly, pure nickel, and tungsten. I would actually like to try playing with thoria bonded tungsten. Its all around the more forgiving. Ultimately however I would like to come up with some small possibly surface mount triodes for people to mostly just play with. Something with a little geek sheik factor. Perhaps even surface mount power tubes since people use FR4 these days and it can take the heat so to speak. There is no need to re invent the wheel. I want something new and cool, and to be in the position one day that if Russia and china say to heck with it, i can at least do something. I just heard however that JJ died and his son is taking over the company. I have met them both a number of times and I believe this will actually be a good thing. The son is competent and has been shadowing his dad for man years now. I am also kinda eyeballing the lowly 45 triode. They are a very easy design to build. Wide tolerances and kinda cool looking. I would have to sell them for like $60 each, but there may be a novelty market in it. What would you think being you are the only person actually reading this thread! I could also do a nice package with 4 tubes and two output transformers type of thing. Kinda sharp looking.

[Stonent]

I can say with absolute authority that Tube manufacturing is NOT illegal anywhere.

I can say with absolute authority that tube manufacturing is illegal in plenty of places. Examples: in the middle of a runway, war graves, inside my mouth without my express permission, Yellowstone national park, Westminster Abbey etc. etc.

The Queen's bog?

[calexanian]

I should start another thread. Places where things can't or should not be done. O0

[calexanian]

That don't look too good. 3.5 X 10-4



Oh, thats why.. its a pile of junk on the garage floor! hahahahaha.... I need a cold trap. I froze the inlet tube and the pressure dropped big time. A trap and some liquid nitrogen will get me where I need to be. I will get one of those nice rubbermaid carts and make it all pretty like the green unit in the background. That particular unit was from Hughes Electron Products and built in the late 40's early 50's and it still works.