migrating fm stations on my Zenith K731

[jpdylon]

1st, check the 12DT8 that sitting near the tuner assembly. That is the FM oscillator and detector. If its faulty it will cause major drifting problem. This isn't the most likely cause of the problem but its a good place to start

Also consider replacing the selenium rectifier with a modern silicon diode. A 1N4007 would work well for this purpose. You will need to add some dropping resistance to bring the voltages into spec. The silicon diode is much more efficient than the selenium rectifier. When the selenium starts to fail. te B+ will drop, which may explain your symptom.

Definitely replace caps. Given their age the are probably more like resistors than capacitors. If you want to continue to use this reliably its a good thing to do. Most of the zenith chassis of that era are easy to work on and are fairly spacious.

If you plan to run this out of the cabinet or with test instruments, you'll need an isolation transformer to prevent your electrocution or damage to your test instruments.

[burnsyaz]

Anyone know where to get the schematic? I googled it but I haven't come up with anything yet.