Well, That fixed it! I decided to go ahead and rebuild the can so I stopped on my way home at the local electronics surplus place & got all 4 caps for a grand total of 87 cents. Pulled the can & disassembled it, removed the mica disc & used a dremel to trim the pads so they didn't touch any more, put it all back together & soldered on the new caps. Cover on, back in the radio & now it works, no more static & tunes in lots of stations! Now it's time for a recap & alignment. There seems to be some distortion in the audio on FM that's not there in AM but hopefully an alignment will help that.
Thanks so much, I couldn't have fixed it without your help, Mark
: This is classic Silver Mica Disease. You may be able to avoid rebuiding the discriminator, though.
: The leakage seems to be between pins 3 and 5 of L15. The capacitor going between pins 4 and 5 is a 15 pF capacitor, eventhopugh it is not shown on the schematic.
: Try this. Disconnect all leads to pin 4 of the discriminator and rebuild the circuit with a new 15 pF capacitor under the tube. Your voltages may come into line and FM may come back.
: Even if you wind up having to rebuild the discriminator, you will need to do the 15 pF replacement out of the can.
: By the way. The capacitor on the primary of the discriminator is 24 pF the two on the secondary are 68 pF.