Cobra 2000 GTL

[HavaV10]

Hello all. Working on a 1978 model Cobra 2000. It's been very chopped up and trying to get it back to stock. The issue with it, will the volume turned all the way down there is still white noise coming out of the speaker. Not loud but you can hear it. I put in a new Volume pot and did a full re-cap on the mother board with no change. Just thought I'd ask if someone might know what to look for that is cause this noise leak through the speaker. Thanks.

 

[BayouRadioAmplifier]

hmmm. yes, I had some radios with that problem.

the audio amp IC TA7222 goes bad.
all that crackly noise out the speaker.

more tests: put in PA mode and connect a speaker to
the "PA SP" jack. listen for the noise.

- Transmit in AM mode and listen on another radio.
key up, MIC gain all the way CCW (no audio in)


Also: on them radios, another "hack" that is done, is the TONE or RF GAIN
control will be wired in place of VR10 AM CARRIER POWER.
This hack is OK, if feeding a Palomar or Texas Star amplifier.