I would guess that's mostly hydrogen, hydrogen has the fastest ionization time I believe. There's no "getter" to capture impurities out-gassing from the tube's metallic elements, they were super-pure to begin with. Your tax dollars at work! Bet it doesn't work so well anymore though the hydrogen probably seeps out a lot in storage too
Steve
Yeah they weren't spending the cash on producing those to make anything robust enough to use gaseous hydrogen. The ionization time of the 2D21 is relatively slow. Its de-ionization time is much faster.
Krytrons were used to fire the exploding-wire detonators in implosion bombs, where nanoseconds mattered. I think people use lasers now.
That tube was accidentally sold at the surplus shack at Los Alamos national lab. Some kid bought it and sold it to me for $20.
Commonly called "Booth Boxes" or "Wall-Boxes" these used to be (and still are in a few places) jukebox remote controls that displayed a list of the songs available and a coin acceptor and push button system to make your remote selection on the in-house jukebox.
Not unlike a dial phone in many ways - used a pair of steppers - one for the letter (up to twenty) and a second for the number (up to ten) to make a selection of one of up to two hundred songs.
Some photos here:
The off page connections are mostly switches. I'll find the wiring layout diagram and post it a bit later...
John :-#)#
From the service manual - the sequence of operations guide:
Not unlike He-Ne laser tubes out-gassing He through the glass and failing back when LaserDisk players were somewhat popular (80s).
John :-#)#
Doesn't have the warm sound. Doesn't even light up!
The selected neon lamps were some of the most rugged electronic devices ever made, almost impossible to destroy short of physically smashing the envelope. Extreme heat, extreme cold, hundreds of G acceleration, exposure to gamma radiation for weeks, etc. didn't affect the operating characteristics very much.
Yes, that might work - at least as a starting point. Need to poke at the values a bit and keep the patent design in mind too - I suspect the sensitive gate SCR didn't exist then.
Thanks!
John :-#)#
Neon lamps eventually fail. I think they sputter their gas away.
The larger thyratrons I was last working with did use mercury, in primary radar modulator (pulses up to 20 kV * 100 A = 2 MW).
They were not ignitrons.
Last time I checked they were off the Munitions List for both the DoD and Commerce Dept, so they're probably obsolete for bomb use. I have about half a dozen in my drawer that an IBM colleague gave me when he retired.
Cheers
Phil Hobbs
Could use an optocoupler to level-shift the trigger pulse and a PIC...that's not much fun either, though...
There were mercury vapor rectifier tubes too. I think the mercury reduced the voltage drop.
120VAC is the standard and has been for a long time. But there has reportedly been a gradual escalation in the actual voltage sent out by power companies over the years. Not sure how credible the anecdotes are, but people have been complaining about it for a long time, e.g.
I don't think I've ever seen anything under 119V or over 126V, myself.
-- john, KE5FX
120.45 RMS on my bench.
Nah, they are just xenon-phobic :-)
Interesting. Make and model? Maybe an article?
Thanks,
Joe Gwinn
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