In Reply to: Magnavox FM not working posted by rickl on March 13, 2017 at 08:46:57:
A quick review of the schematic reveals that the AM & FM tuners share much of the same circuit with different coils, RF and IF transformers switched in and out of the circuit to allow the circuit to function either as an AM or FM tuner. I would first uses a cleaner such as Deoxit to clean the AM/FM selector switch, next I would look at the 6AU6 limiter and 6AL5 discriminator part of the circuit which appear to only be used by the FM. My test device of choice to find the point of signal drop out in a tuner is signal tracer with a demodulator probe. You can signal trace with a scope but you have you know what is the proper wave form is for the part of the circuit. With the signal tracer you hear the demodulated audio signal the tuned FM station is broadcasting. It really is signal tracing for dummies like me.
This post is made possible by the generous support of people like you and our sponsors:
Topic - Magnavox FM not working - rickl 08:46:57 03/13/17 (4)Follow Ups
- RE: Magnavox FM not working - elflow 17:23:33 03/13/17 (1)
- RE: Magnavox FM not working - rickl 09:06:12 03/14/17 (0)