Re: XM radio antenna
Thomas, you didn't say WHERE they installed your antenna. Isn't your Coachman a Class C? If so, then they probably mounted the antenna on the hood somewhere.
My XM comes in through my GPS (Garmin). I have a magnet mount that sits loosely up on the dashboard. The reason that I left it like that is because I didn't want to snake a long wire up to the roof through my MH's body.
Having said that, I have to move that "hockey puck" around from the front to the side window depending on my direction of travel. Sometimes that isn't enough and the signal drops out.
The point I'm making is that your XM antenna is a satellite antenna. It has to have a constant view of the sky. The hood of a Class C motorhome is going to be shielded by the MH body at some point in your travel. That's when the signal will be spotty or drop out completely.
Mount that antenna up on the top of the MH and you won't have any problems.