screaching through stereo speakers when mic keyed

Need to know your setup. What CB are you using, is it stock (untouched), Vehical it is being used in etc.

 

Install a good mic like an RK56 that will cancel the background noise and eliminate the feedback.

 

INTRESTING IDEA .....

It might even work Also Try ferite beads on the speaker leads i get some through my computer speakers and the beads took care of it.

 

It's a ground problem. Try grounding the case of your radio to the bolt that holds the seat frame down or try running better coax and also check to make sure that your antenna is grounded well,maybe run a ground wire from your antenna mount to your frame.

BUT IF IT STILL DOES IT THEN.......

GO BACK TO THE CB SHOP THAT DID YOUR WORK AND HAVE THEM TAKE OUT THE MOD KIT OR SWING KIT,THEN SET THE RADIO FOR NO MORE THAN 100% MODULATION AND THAT WILL CURE YOUR PROBLEM.A POORLY TUNED RADIO WILL DO THIS JUST AS BAD AS A RADIO WITH A POOR GROUND SYSTEM.

I know thats not what you want to hear but the way it is is the way it is!

 

I'd try the ferrite beads as WA4GCH suggested, this will work most of the time if the radio has not been tampered with.