![]() D7 should be checked - tested - both Band and Anode in TX mode and RX mode - if D7 goes "off" in RX mode - there may be a problem related to the RF diode routing used to send AM or SSB IF thru that Crystal Filter FT-001. I'm still here, but If TR22 shows ok, the only other amp I see that even uses this "pole" of MODE for AM is TR7 - right off the IF filter FT001. If you can get at TR22 - pull it - see if AM RX returns - for the MODE switch overrides the RX/TX of TR21 stuff So if they modded anything about the area of the Audio amp - they may have been trying to run it full throttle for max swing stuff. There is a scary section for the radios' AM modulation using TR22 TX which INJECTS past TR21 but AM and SSB gets amped by TR21 in RX. This whole mess with AM may be from his efforts to keep RF out of the radio from a leaky amp or noisy shack - that's a lot of RF and hash chokes in there. So if that cap isn't right you will not see any signal.SSB is a totally different section. Make sure all the caps are in correctly - ANL inclusive - can may your day because all signal goes thru that filter section. But that same line use the AM Detectors near the back of the radio to help determine AGC values - it affects the amount of signal that AM RX uses when strong AM signals are present. ![]() Ok, for some simple checks - Locate IC3 and probe Pin 7 - it's the mixer for Mic Amp - but it "taps" the line for AM mode. ![]() This one is unique, the AM IF is interesting. ![]() He prolly' got it from a guy that ran an amp. ![]()
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