[Amps] Shelf life of 3CPX800A7 tubes

[Gudguyham at aol.com]

In a message dated 12/26/03 10:21:10 PM Eastern Standard Time, KD7EFQ at aol.com 
writes:


> 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? 
> I 
> understand the 3CPX800A7 is a direct drop in replacement for the older 
> 3CX800A7's. 
> If this is in error, Please let me know. Thank You.
> 

I do believe it is a drop in for the 3cx800 itself as far as I have heard.  I 
do not think that there will be much of a problem with the tubes if they have 
been on the shelf.  There may be a procedure you can follow at start up like 
running the tube for several hours before applying plate current or something, 
but I don't think it is a problem.  I am sure others may know better, but as 
I recall I have used older tubes with no problems.  The ceramic tubes are 
pretty good in that regard opposed to the glass envelope tubes.  I have a Titan 
425 amp also.  73 Louie