[Amps] 3cpx800a7 or similar tube storage

[Rob @ Peg Pohorence]

I have been reading lately on this Reflector allot of great information about High Power Transmitting  tubes, and about the good and bad about the  Russian tubes. 
   
  I have an Amp that uses a pair of the 3cpx80A7 tubes , They are about 1 year old, and are Eimac brand. They are working perfectly!
   
  I thought it would be a good Idea to have a pair of spares, for the amp. I put out a few Want Ads, and received several responses , for New OLD stock (NOS), and some for Medical Pulls. 
  A pair of these tubes NOS or Medical Pulls were quoted to me in the $600-$800 range and more.
   
  I asked about any kind of warranty and ,only one fellow would guarantee that they would work, the rest of the offers  were essentially AS IS!
  
 
  After reading the info here in AMPS about Conditioning Tubes, I have a few questions:
  1. Upon receipt of a set NOS or Medical pulls , how should the average Ham with limited test equipment test the tubes before placing them in the  amplifier?  
   
   I am thought  that maybe  an Ohmeter should be used to first test the tubes for shorts, grid to filament and then maybe a 220 Variac connected to the Amplifier AC Input lines . But I am not sure of the voltages or   timing to condition the tubes? 
   
  2. If the tubes work OK, and the original tubes are put back, what would be a reasonable time to rotate the Med Pulls or the NOS tubes purchased as spares? I have read that the tubes need to used occasionally to burn off any air that may have been leaked into the tube?
   
  Your comments would be appreciated>
  rob 
   
   
   


                  Sincerely, Rob, Peggy , and Maggie Sue Papillion  
   
  "The Venerable dead are waiting in my library to entertain me and relieve me from the nonsense of surviving mortals."
Samuel Davies
1725-1761  












 		
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