[Collins] 75A4 RF Gain Action

[Wally Klinger]

Hi All:
 
Working on a 75A4 that seems to be low in sensitivity and no indication on the S Meter.
 
Looking at V8, trying to capture voltages on the pins.  When I lower the RF gain control, the meter does not deflect like my other A4 does.  I can adjust the RF gain to deliver -5.7 volts on the meter, but it calls for a S9 meter reading which I can not generate.
 
Aside from the tube, any other parts here at this stage I need to troubleshoot, such as C75 the coupling cap, or C77 on the cathode?
 
Or any other ideas?
 
73--Wally W9BEA