Well, we may have multiple problems here. But I did get the audio
back...for now. I decided to check and see if there was any sidetone.
With a dummy load hooked up I tapped the leads from the power set switch
together - had power our but no sidetone. Don't know what possessed me,
but I decided to take a listen through the headphones. Voila, sidetone,
and after tickling around a little bit I had some receive audio.
So I messed with the selectivity switch again and bingo, full audio!
Pull the headphone plug out - silence.
So, I guess I'll definitely clean that switch, then go after the
headphone-jack/speaker circuit to see what gives. I'd like to think
that it was something as simple as a bad connection at the jack, or even
if the loud signal from the calibrator just blew out the speaker.
Things are never that simple, though.
Then I can try out some of the suggestions on my set-screws.
73,
Tom
Mike Bryce wrote:
Tom...
for the tuning knob, try this.
Get a hunk of line cord from the junk box. take the coating off and pull
out one single strand of copper wire.
insert the copper wire into the screw hole, then the set screw. The
copper will give the threads on the set screw something to latch onto.
If the hole is really bugger up, you may need two strands.
as for the audio bug,
Scope the center wiper on the volume control. I bet the selectivity
switch may just need a good cleaning. A scope will tell if you have
audio at the selectivity control by looking at that center wiper on the
volume control.
if you don't then work your way back towards T2 on the #80356 board.
It's possible with extra large signals, you have some bugs in the d2-d5
diodes used in the receiver product detector
BTW... miserable board to get out of the radio!
Mike, WB8VGE
SunLight Energy Systems
The Heathkit Shop
http://www.theheathkitshop.com/
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