** Spare tubes last indefinitely unless there is a micro-leak in a seal.
If my amplifier used a tube that was still in production, I would not
keep a spare, and I do not.
-- Hazards to the 3cx800A7 are:
1. Barium migration from the cathode's emissive-coating to the
gold-plated grid caused by too-much heater-V. (symptom: P-out drops
steadily during AØ)
2. Cathode coating flakes off due to exceeding the anode-I rating. (can
cause grid-cathode shorts)
3. Gold evaporates from grid during intermittent VHF/UHF oscillations
(causes internal leakage and/or anode-grid flashovers during operation -
also causes reduced emission due to gold meltballs sticking to cathode).
>Hello, I have a Ten Tec Titan 425 amp that takes the EXPENSIVE 3CX800A7
>tubes. I am considering purchasing a set of brand new 3CPX800A7's for
>spares while
>I can afford It. Does sitting on the shelf in a controlled temperature
>environment for several years degrade the quality of these tubes in any
>way? ... ... ...
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|