[Drake] TR-4C Problem

[Larry - WA2DGD]

Hello All,

I've recently noticed a new problem with my TR-4C. At certain times, the 
receiver losses a significant amount of sensitivity, signals drop by at 
least 20 db. Even the calibrator signal, which I can usually peak to S9 
+20 on 40 meters, drops down to a maximum of S 7. I'm not sure if its 
heat related because the rig can be on for quite awhile before this 
problem occurs. When the problem does occur, the transmitter works fine, 
full output.
It seems like I'm losing the RF amp, V7. Do tubes get intermittent or 
just fail altogether.
I haven't gotten any time to get into the rig as of yet, but would like 
any suggestions before I do.

Thanks
-- 
73
Larry
WA2DGD
K2 #1672