[R-390] Calibration Osc and 2nd Osc questions and AGC issue

[Larry H]

Great work Tom.  Weak agc is usually leaky caps on the agc line.   C551 is the large cap in the square can and not only does it leak like normal caps, but it also leaks to ground.  Isolating the agc line is helpful by unplugging units or removing the link on tb102.  Of course, a tube or z503 could be impairing agc gain.  Sometimes you need to remove the connection from R546 to C547 to measure correctly.
Regards, Larry