[Collins] 4D32 question

[Dr. Gerald N. Johnson]

On Sat, 2007-08-04 at 07:48 -0400, jeremy-ca wrote:
> I'm wondering if those USAF surplus tubes that have been showing up are OK. 
> My concern is with gas and vacuum deterioration.
> 
> Carl
> KM1H
> 
> 
The only thing would be to first cook them with filament/heater power
alone for a day or two or longer. Then build a gas checker and see if
the gas is low enough to be usable. Lots of leads to be sealed could
mean that the getter can't clear up the gas. A fading getter deposit
would hint its all used up. And warming the getter deposit by some heat
more than the heater may speed up its action.

Its unlikely the seller has done any of these things to the tubes so it
wouldn't be smart to pay much for them.
-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer