[simpsons]

Hi Skip

Many thanks for the background information, you were a brave man to take this job on.

Before passing on tips on FM fault finding, when you removed the stereo decoder you did link the audio in- out on the socket? No offence I assure you.

Secondly, your signal generator. Is it AM/FM or AM only. Should it be the latter, then is the EM87 tuning indicator bright enough to use as a signal level meter. An AM modulated audio signal presented to the FM ratio detector is just the opposite to what the ratio detector expects. It is designed to reject AM modulated signals.

As the IF for AM and FM is common, although emission tested, my first task would be to replace the ECC85 or at least make sure it works in another radio. Opening up the FM tuner can to check voltages or decoupling capacitors will test your good nature to to its limit!

Chris