[Hammarlund] Weird HQ-110 problem

[Phil Galasso]

I am having an unusual problem with my HQ-110 receiver. With no signal being
received in "REC" (AM) mode, there is no background noise. The receiver is
completely silent. Above a certain signal threshold, the S-meter will move
and I will hear a signal, which sounds normal. At the threshold, the signal
sounds badly distorted. With the exception of the distortion at this signal
level threshold, it sounds as if there is a squelch circuit operating,
despite the lack of a squelch circuit in this receiver.

I replaced two resistors, the screen resistor for the pentode section of the
6AZ8 tube (last IF stage) and a resistor in the cathode circuit of one of
the diode sections of the 6BJ7 tube, as they had changed value with age.

I tried substituting tubes, but I did not have a 6BJ7.

Any ideas? I have been pulling my hair out over this.

Phil G.
K2PG