[MrFixr55]

Hi Lawrence,

Does FM work?

Check cathode voltage on the 2nd IF / Detector / AVC tube.  It should be very low. If high, check the push buttons.  Alternately, ohm between the cathode of the 2nd IF and ground. It should be about 150 ohm.  If the switch is dirty, the resistance will be much higher.  The "PB1" (Radio / Phono switch?) does several things, including opening the cathode of the 2nd IF / Detector through a 150 Ohm resistor from ground to disable the radio when the phono is used.  Clean the heck out of PB1. 

One terminal of each of the secondaries of the various IF transformers connect to the grid of the next stage (except for the last one which connects to the plate of the detector diode.  The other terminal does not connect to ground; it connects to the AVC Line.  The purpose if the AVC Line is to vary the negative bias on the grid returns of each of these transformers.  The more negative the voltage, the less the gain. AVC generally varies between 0V and about -10V or more, depending on the strength of the signal.  Shorting AVC to ground may bring the set alive (or saturate it).  Alternately, a power supply can be used to force the variation of AVC voltage.  You may be able to measure the AVC voltage across capacitor C305.

One strange thing is that it appears that the 2nd IF stage is not under AVC, but there is a 2.2Megohm resistor between the grid return of the secondary of that transformer and ground.  that does nt make sense to me.  It could be an issue with the drawing.

Hope this helps.