[R-390] AGC problems

[dog]

I've got a couple 390A's. One (Dittamore) is pretty much covered up but 
I think it still works, and the other (EAC) is on the bench being worked 
on. I've got most of the modules out of the Ditta and use them to check 
in the EAC which is pretty much operational. Long time ago I started 
replacing the caps in the RF and IF sections and finally got done the 
other day. Orange drops in one IF and couldn't deal with doing that 
again so I got Panasonic ECW types to put in the other. Any how could 
use a little help.

  With the OD IF module Setting the IF gain pot, R519, I notice that 
150uV into the IF results in too much -VDC at the diode load. I cannot 
reduce R591 enough to get to -7VDC on the diode load. Although if I load 
the gen output with 50Ω I can set the gain to -7V. The Panasonic module 
I can set it to -7VDC without the 50Ω load. With neither module does the 
AGC seem correct, there's distortion. Now I don't have the 'impedance 
matching network' and I'm wondering if that will make a difference and 
if so, how to adjust for it?

I'm feeding the 455 from a Moto 2005HD Service monitor and it's good as 
far as driving a 50Ω load. I read about Chuck Rippel's method of setting 
the IF gain, but it seems to me that that method would depend on where 
you started with the gain setting to begin with. Can someone help me 
with the levels here? I'll get to the AGC when I get the IF gain right.

Most everything else in these receivers is working fine, but I noticed 
just yesterday the OD module has lost the 2K, 1K and .1K positions, that 
is there's no output when switched there. It was working last week. 
Years ago I went through both of these receivers and checked the 
alignments and they were working properly, except for the AGC problem. 
I'd like to get them working properly.

Thanks.