The level of rust on my electronics knowledge is probably an embarrassment
to the amateur radio fraternity, so forgive me if this seems like a dumb
question. But I need some help figuring out an audio circuit issue.
First, the background. I've been running PSK31 on my Triton IV. It was
easiest to just use the sidetone jack for getting audio out of the rig, but
it's tied into the front panel volume control, so I get to listen to the
shrill tones of PSK while operating, which gets annoying sometimes. I could
just tap into the headphone jack, but sometimes I *do* want to listen.
What I want is a straight audio out that's volume control independent, so I
referred to the circuit diagrams and info in the manual, and tapped into
the AUDIO and GROUND pins on the IF-AGC board. Easy enough, and it works --
mostly.
When you crank the front-panel volume control past the second mark -- while
my new audio out is connected to the PC -- the speaker volume suddenly
drops precipitously, and gets very crackly sounding. (I believe the input
to the PC remains unchanged, but I don't have it set-up at the moment to
confirm that.)
It seems logical that I need to somehow isolate the new audio output on the
rig from the PC's microphone input, but I haven't a clue where to begin, or
what type of circuit would be needed to do that. For that matter, I'm not
even sure what's going on to cause this in the first place.
Any specific advice on next steps from someone wiser than I would be
appreciated.
Thanks, Alan
WD0EVX
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Alan Bryant
Denver, Colorado
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