Hello All,
I have replaced all the paper and filter capacitors, I think. I don't see any more. I replaced the 6 paper capacitors in the can and the ones in the bakelite boxes except for the .00011 mf (110 pf) capacitors. Are those also paper? The troubleshooting guide (Ghirardi, 1939 pg. 138) says something about the 51K and 5000 ohm resistor, as well as the capacitor in series with those resistors, in the oscillator section. Both resistors seem good to me. The capacitor looks like the mica type and 110 pf as well. If I can't find anything else wrong, I'll try replacing those two resistors and 110 pf capacitor. Usually when a radio like this motorboats, it's the capacitor that connects power supply negative to the chassis. But that one is ok in this set and connected. This radio tunes in things fine even though it's motorboating. Where may I have made a mistake? What capacitor may have been missing?

Thanks,

Dave

Hello Again All,
The cathode on the 75 had somehow gotten disconnected from power supply negative. The motorboating seems to be gone. I hear a little distortion at low volume. But that may be due to the 1/2 wave rectifier and a tiny bit of hum. It sounds great otherwise.

Thanks,

Dave
:Hello All,
: I have replaced all the paper and filter capacitors, I think. I don't see any more. I replaced the 6 paper capacitors in the can and the ones in the bakelite boxes except for the .00011 mf (110 pf) capacitors. Are those also paper? The troubleshooting guide (Ghirardi, 1939 pg. 138) says something about the 51K and 5000 ohm resistor, as well as the capacitor in series with those resistors, in the oscillator section. Both resistors seem good to me. The capacitor looks like the mica type and 110 pf as well. If I can't find anything else wrong, I'll try replacing those two resistors and 110 pf capacitor. Usually when a radio like this motorboats, it's the capacitor that connects power supply negative to the chassis. But that one is ok in this set and connected. This radio tunes in things fine even though it's motorboating. Where may I have made a mistake? What capacitor may have been missing?
:
:Thanks,
:
:Dave