[R-390] maintenance

[2002tii]

SCott wrote:

>As I was testing the R390
>tubes, I noticed one radio that needed an incredible 22 tubes.  These were all
>fine last year. The radio ran fine with all the bad ( really bad ) 
>installed. Thats amazing.
>I decided I had better get out my spare tester, a Heath TT1-A to 
>verify the condition
>of the tubes and my TV7 All 22 tubes were just totally dead.

Very odd.  So odd, I'd be more inclined to think you have two 
erroneous tube testers.  The 390 beats on some of its tubes, but the 
RF and IF tubes (for example) should run 24/7 for a large part of a 
century without any sign of low emission or transconductance, even 
with poor ventilation.

Best regards,

Don