I had good luck with these on my home station, others have not..

http://www.radioshack.com/product/in...ductId=2103222

http://www.radioshack.com/product/in...ductId=3012599

Wrap your speaker wire (multiple wraps) thru one or more of these as close to the speaker as you can......it sounds like your speaker wire might be acting as an antenna so to speak and pulling the RF out of the air...You can also run your coax thru one as close to the back of the CB as possible..

Galaxy, Connex, and Stryker are brands of radios that I was refering to and they can be quite messy..