22-09-2019, 10:13 AM
Played around with this chassis without finding any simple reason for the howling instability.
Its not earth rivets or paper capacitors, there are no valve screening cans fitted. HT line RF decouplers are new and correct. Valve swaps do nothing.
The internal screen across below the chassis is in place.
Did find a cracked ceramic insulator on the aerial side of the tuning capacitor. I unsoldered the 3 wires and carefully removed tha capacitor with the drive wire still attached. A dose of Araldite secured the insulator. I managed to get it all back together without losing the drive, Philip's multiple wire tuning drives are not to be disturbed if your sanity is to be preserved.
Its not earth rivets or paper capacitors, there are no valve screening cans fitted. HT line RF decouplers are new and correct. Valve swaps do nothing.
The internal screen across below the chassis is in place.
Did find a cracked ceramic insulator on the aerial side of the tuning capacitor. I unsoldered the 3 wires and carefully removed tha capacitor with the drive wire still attached. A dose of Araldite secured the insulator. I managed to get it all back together without losing the drive, Philip's multiple wire tuning drives are not to be disturbed if your sanity is to be preserved.
Boater Sam.
