[Hallicrafters] HW-32-A

[pato]

Could someone help me, in the following problem, in a
HW-32A.
The receiver seems to be working correct, when receiving a
strong station, although the audio could be better. When
reciving a station that requieres that the volume control be
increased (turn up) the receiving station is cover with a
low frequency continuos note of about 40 cycles.At the same
time the "S" meter moves up as the volume control, is
farther increased.
At this moment voltages of the tubes are being check.
Thanks in advance for the help
Franks, WB4EHB