Re: Identifying A HUGE Hydrogen Thyratron (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 15 Oct 2007 12:13:32 -0500
From: Bert Hickman <bert.hickman@xxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Identifying A HUGE Hydrogen Thyratron (fwd)

Tesla list wrote:
> ---------- Forwarded message ----------
> Date: Mon, 15 Oct 2007 09:18:18 -0500
> From: Cameron B. Prince <cplists@xxxxxxxxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Identifying A HUGE Hydrogen Thyratron
> 
> Hey guys,
> 
> Can any of you help me identify this MASSIVE tube I picked up at an estate
> sale? The only markings are 4.8V Reservoir Voltage printed along the side.
> 
> http://www.rideware.com/images/eBay/20071011/DSC01254.jpg
> http://www.rideware.com/images/eBay/20071011/DSC01255.jpg
> http://www.rideware.com/images/eBay/20071011/DSC01256.jpg
> http://www.rideware.com/images/eBay/20071011/DSC01257.jpg
> 
> I believe it's the same as the one shown on the Wikipedia page here:
> 
> http://en.wikipedia.org/wiki/Thyratron
> 
> All I can make out from the photo is General Electric. Any ideas?
> 
> Thanks,
> Cameron
> 

Hi Cameron,

Nice find!

It looks like it may be an elusive VC-1257 - one of the largest glass 
thyratrons ever made, for use in high power RADAR power modulators - 33 
kV, 2 kA peak. Its a fine collectible tube and a sure conversation 
starter. The tube used a titanium hydride reservoir that could be 
carefully adjusted (via a separate reservoir heater) to keep the 
hydrogen pressure at an optimum level. If the H2 pressure is too low, 
the anode will overheat, and if too high, the tube may suffer from 
premature cathode-anode self breakdown.
http://home.earthlink.net/~webdisk1/oddtubes/oddtubes.htm
http://home.earthlink.net/~webdisk1/oddtubes/ChathamVC1257.htm

You can read a bit about thyratron history and the place held by this 
tube here:
http://www.xs4all.nl/~aobauer/Evolution%20of%20Hydrogen%20Thyratron.pdf

BTW, here's a 50 MW line pulser that uses a 1257 in case you need 
something to go with your tube. 160 kV at 312 amps output... :^)
http://tinyurl.com/25dkre

Bert
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