I'm new to antique tv repair, and just recapped my first one. I replaced all of the electrolytics, and paper caps, but left the micas alone. The set works ,but an old friend who used to be a tv repairman during the 40's-50's came by to help me adjust it up. He said that the agc needs adjustment,[ has very strong blacks, with a buzz present in the sound] and we started to look for said adjustment, but couldn't find one. The schematic doesn't show one off of the agc tube, but there's a resistor in the cathode of the agc that appears to be where you'd expect to find one. What would anyone suggest to correct this problem?
My friend suggested replacing this resisitor R39 with a pot to allow adjustment. What do you think?