[R-390] R390 V511 / Z503 Wiring

[thoyer]

Have my 390 working but while doing the If alignment, I was having trouble
getting Z503 to peak. Upon inspection, someone was in this area before as
Z503 only had one nut holding it in.
 
Now I have been through the Z503 follies previously on an R389 I repaired
for a friend so I'm pretty familiar with this area. We ended up having to
source another Z503 as his was open.
 
Mine measure 5.5 ohms per the manual. I have another IF module here where
Z503 measures 15 ohms.............
 
OK, getting off topic... I ended up removing Z503 and found the insulation
damaged on the wire that connects it to the plate of V509 - good, maybe this
is shorting somewhere and causing my issue.
 
Before reassembling I inspected the whole area checking values and wiring. I
noticed that pin 1 of V511 ties to the 470 ohm side of Z503. Per the
schematic the only thing on Z503 should be the 470 ohm (2200 on sch) and the
0.01uf cap (R554 and C542). But as I said, there is a wire at that junction
that runs over to V511-1. I checked my "parts module" and it is wired the
same way so I'm "assuming" that this is a circuit change that is not
reflected in the schematic????
 
The IF module in my radio is SN 388 (Collins). No MOD indicated
 
The parts module is a Motorola SN 1229, MOD 1 indicated.
 
Tom
W3TA