[Collins] 75A-4 dead on 40 mtrs only

[David Propper]

HI all,

Just finished re-capping my SN1135 75A-4 and it was working beautifully for 2 days. Last night, 40 mtrs just went absolutely dead. Receive sensitivity is fine on all other bands. I pulled all the crystals just to be sure it wasn’t an intermittent contact. Looking at the schematic, I suspect that possibly C10- a 300mmf mica padding capacitor across the first stage coil might have gone south.  This cap (postage stamp red mica) does have a blister on it at one end.

Any other thoughts / recommendations as to the culprit ? I probably won’t have a chance to work on the receiver until later this week.

Any help would be appreciated.

Thanks and 73,
Dave, K2DP