Maybe you guys can direct me a little. My AC3 has been showing signs of bad
caps, especially in the bias section ( one of the bias caps measured at
700MFD). I replaced all the caps in all sections, using 33MFD 160 volt caps in
the bias section, and while I was there did the diodes. After reassembly the
bias was adjustable from 41 or so to 80 volts. TR-4C was running well. Today
after operating for an hour or so, the transmitter started to show very high
plate current, so I checked the bias and found that it was either zero or above
.4 amps, without much adjustment between the two, and of course when higher the
xmit relay was engaging. Reducing xmit gain would not reduce the plate
current. I measured the voltage at the plug and the bias is now only
adjustable from 52 to 94 volts, which I think is too high. There's not much
else to replace in the AC3 except the bias pot and two resistors, both of which
measure within tolerance statically. Any thoughts?
