I have a Magnum S9 in a Class A motorhome. The radio worked before I installed it in the motorhome. It was in my work truck before I retired. Once I installed it I noticed I was only receiving. When I would transmit I sounded garbled and like I was on another channell. I sent the radio out to get fixed. I was told it was out of tune and the mic was bad. He tuned the radio and sent it back. I bought a new mic. Had a friend park down the street about a 1/4 mile away. Anutime he would talk all I got was a buzzing sound. When I tried to talk all he got was a buzzing sound. Maybe a bad new mic?