[AMPS] testing tubes in place

[Rich Measures]

>
>Thanks a huge bunch for all the helpful comments about testing the 3cx800
>tubes in my Alpha 89 for full output. 
>
>One of the most interesting comments was to test each tube individually.
> I don't know how to test one tube at a time. 
>
The first test I perform is with a high-pot. tester.  I measure current 
leakage between the anode and the grid at double the rated anode 
potential.  More than c.10uA indicates a problem that could damage a 
healthy amplifier.   If the leakage is equal with both polarities, the 
tube probably has a leaky seal.  If the positive pol. leakage is greater 
than the negative pol. leakage, gold-sputtering damage is indicated.   

>Can I take one tube out of the RF deck and run the amp on one tube? What do
>I have to disconnect or reconfigure to do this. 
>
With one tube, the tank operating Q will be c. double.  Do not exceed 
600mA per cathode in N-Zero-N operation.  The open socket should be 
blocked with a chunk of urethane foam to maintain air pressure.  



Rich...

R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures  


--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm