Hi Peter,

The D2 referred to is the D2 in the ALC circuitry which is located on tag strips in the chassis just outside the PA/Driver compartment - I think this is what you referred to as the D2 in the grid circuitry of V2? However, I don't think that is your problem. The page you referred to in the service manual assumes (although it doesn't say so) that the meter is going full scale to start with and "no ALC indication" means that there is no deflection back from full scale.

So, your problem would seem to be with the metering circuit would be my guess. As a start, try cleaning the contacts on the PO/IC/ALC meter switch. The next thing to try would be clean the contacts on the main chassis mounted relay, RL1. The ALC meter signal passes through both of these and if the radio has been sat for a number of years then these contacts may need cleaning. Other things that might stop the meter from being able to be set to full scale on ALC would be a dead Q6 or open circuit/ dirty VR2 on the processor board. The schematic of the processor board later in the service manual shows what voltages you should be seeing on Q6. If you are seeing the correct voltages on Q6 then the only thing stopping the meter from going full scale is VR2 and the switch/relay contacts between the processor board and the meter.

You should still be able to check that you get SSB output by tuning the radio and set the mic gain to, say, 3, and then key the radio and check for speech peaks with the radio's meter set to Ic. You should also be able to see RF output on an external power meter. Hopefully you can get the ALC working at some point.

Good luck!

Peter
G4DJB

So here is what I currently have onboard, mine is an E model serial 240595, hope this helps

BLANKER???? PB1582B
REG ? ?????????? PB11547B
MOD???????????? PB1184A
AUDIO????????? PB1315A
RF???????????????? PB1181B
LO-IF??????????? PB1183C
HF-IF??????????? PB1180