#6511
Peter Heembrock
Forum Participant

Check all the power supply voltages while the set works and when it does not…look for any major change…
If some of the tubes are on the weak side this may affect the B+ voltage which may mess with the AVC circuit…
If nothing comes from this then all I can suggest it to check all resistor values ( cold and after running for a while…freeze spray comes in handy sometimes for finding drifting parts.) I assume all the caps have been replaced.

A tube may be weak or on the edge of being bad as well in the RF section…

PH