[R-390] AGC Troubleshooting

[gary.biasini at shaw.ca]

I followed Charles Steinmetz's troubleshooting procedure for AGC issues and
the following resulted after tuning to a very strong BCB station:

 

Voltage Terminal 3  & 4: -0.37V - not good

 

Then step 2:

 

Resistance Terminal 3: 460k - maybe passable

Resistance Terminal 4: 24.6k - horribly off spec

 

So, my problem is most likely in "any of the several dozen bypass caps on
the AGC line in the IF and RF sections, or leakage to ground in one or more
of the mechanical filters".

 

Now my ignorance shows up.  How do I identify what are bypass capacitors?  I
assume that these are capacitors that go to ground?

 

I also note that, on the very strong BCB station, I get no sound output
until the RF gain is up to 8, if that helps narrow down where I should start
searching.

 

Thanks in advance for any help.

 

Regards,