[R-390] Local and Line pots plus AGC

[quartz55]

Charles, et all,

I have an IF module that had some really bad filters and the AGC in that is non functional, I'm in the process of repairing the filters now, but on the IF module that does work, here's what I get feeding the service minotor into the BNC (balanced) on the back of the 390A, measured at 16KHz BW.

-110dBm = -0.58VDC TB102, 3&4 = 0 on the carrier meter
-100 = -.6VDC = 0
-90 = 0.8VDC = ~2
-80 = -2.8VDC = 20
-70 = -3.6VDC = 40
-60 = -5.2VDC = 55
-50 = -6.6VDC = 70
-40 = -7.9VDC = 80
-30 = -9.0VDC = 90
-20 = 10.3VDC = 100
-10 = -11.7VDC = off scale
0 = -13VDC = o. s.

How do these numbers look as far as AGC goes?  It sounds real good on the diode load through an LM amp.  I haven't been through the book yet on setting up the IF gain, but RF, IF coils have all been aligned.

How much AC hum should I be seeing on the local and line output?   There were also some strange wires and resistors in the IF not in the schematic I removed and the caps have mostly been replaced.

Dave