JB wrote:

I have always found that tube testers only find bad tubes, but never good
ones. Always test RF tubes in-circuit for proper operation at the Fo.

Tube life for sweep tubes in RF amps should be rated in milliseconds. Ah
the good old days when Radio Shack had Lifetime tubes and free battery
cards.

Jim, ac6tk

Yep...may check as new on a tube tester...may still work 80% on 80
meters and may have very low output on 15 or 10.

I think it was Drake and the 6JB6s? I believe they specified Sylvania
brand for their xmtrs. It proved true to me. Tubes ordered from them
always got the best output on 15 and 10.

-Bill