D-104 5 pin to Madison..hearing chirp when unkeying

[tuner]

Hi Guys, been off the air for a bit, I'm getting an ear piercing chirp on my Madison when I unkey my D104. It goes away if I unkey very slowly.
Anyone know a fix? Any suggestions would be greatly appreciated

Thanks, Tuner

 

[ExitThirteen]

Assuming the mic modulates and keys up okay, jump pins 2 and 4 on either the mic plug itself, or on the mic jack in the radio. That fixes the issue in some radios. It ties the PCB and audio grounds together. Let us know how you get on.


~Cheers~

 

[tuner]

Thanks very much , ill give it a go !

 

[tuner]

Looks like the grounds are fine, I think I've got a little to much modulation.

 

[ExitThirteen]

I'd recommend putting that jumper in anyhow, this removes any possible chance of a ground loop fault. If your modulation is too hot, the modulation limiter may have been pulled, and should be replaced.



~Cheers~

 

[space cowboy]

I had a president grant that would do that with a d104 m6b. only when I would unkey slowly I would be able to hit a "sweet spot" that would just squeal continuously. the faster I unkeyed, the shorter the squeak. I never could get rid of it. it was my own unique roger beep.
I just figured (ok, guessed) the transmit was still engaged when the receive came back online resulting in feedback.