[R-390] AGC Line Again

[Charles Steinmetz]

Dave wrote:

> I had the dreaded IF filters going bad. As I remember, you can't tell
> which one it is. What's happening is the internal resistance of the
> filters is becoming something measurable in relation to the AGC circuit.
> And no matter which position you have the BW in, that resistance to
> ground is always there. Look at the schematic.

Leakage through the mechanical filters is certainly possible, but 
leakage through any of the myriad capacitors is *much* more likely 
(hundreds to thousands of times more likely, as of this date, but that 
could change in the future as more mechanical filters start going bad).

I have posted my AGC Troubleshooting Procedure from time to time over 
the last few years, and will take this opportunity to post the latest 
version (in a separate post).

Best regards,

Charles