[Hammarlund] HQ-140XA hum

[Ron Tate]

Looking for help on a HQ-140-XA.  Before a shotgun approach in approaching the hum problem on an HQ-140XA I thought I would throw it out to the list.  I'm sure that the hum is caused by C-52 -ABCD: a 10/500-20/450-20/450-10/50 VDC.  The 10/50 is used to bypass the cathode 360 ohm resistor on the 6V6 audio output tube.  By the way, the HQ-140X uses a separate capacitor for the audio cathode bypass.

Does any know a source for a replacement capacitor?  It doesn't have to have the 10/50 VDC.

By the way, this HQ-140XA has an audio mode that uses a transistor, audio transformer, several glass diodes, and tubular capacitors.  It ties in to the 6V6 audio output cathode resistor and by-pass cap.  I assume this is where the 5 VDC or so is used to power the mod.  The mod is extremely well made and mounted.

Any source for replacement caps or other trouble shooting tips would be appreciated, but this looks like the old electrolytic story.  Any info on the audio mod would be helpful to document the schematic.

First posting...great reflector.

Regard,

Ron
K4AUW since 1954.