Hey I am having some similar problems with my CB. It's a Galaxy 959. I'm a company driver and used to be in a Freightliner. The CB worked like a champ and I had no problems. Even had a 5pill linear amp and talked half way across the country while trucking. Well the Freightliner bit the dust and I got stuck in a brand new Volvo VN780. The CB sounds like crap and comes out of the radio speakers with the radio off and the amp off. So there's no way I would even be able to use the amp right now. There's a lot of RF interference. The antenna is a Wilson 2000 Trucker and is grounded to the door with a perch and everything else is grounded as well. I'm guessing that the interference is coming from all the computers in the truck. Does anyone know how to stop all this interference?