I have an old Sansui 800 receiver, which works well, but now doesn't switch into stereo with a strong stereo signal. This happened after I lent it to someone. (hmmmmm...)
I understand the basic theory of FM detectors, but am hazy on the theory of stereo switching, and can't find anywhere a simple explanation of multiplex decoding.
The unit is solid state discrete transistor circuitry, and I have a circuit diagram.
Grateful for any assistance.