XM antenna placement
I installed XM satellite radio using the car kit and a standard 12 volt car radio. I initially placed the antenna on the inside of a port in the salon. ( attached to the plexiglas ) I got good reception in the harbor, but to my disappointment, once underway I discovered reception was intermittant depending on my boat's direction of travel. I moved the antenna to the top of the transom and have gotten good reception ever since. The instructions with the car unit said the antenna needs a ground plane ( gets this from the sheet metal on the car) but the reception problem seemed to be resolved when I moved the antenna to the outside of the boat.