Yes - that was my understanding when we added sat option. The existing wiring path-splitters, powered outlet etc wasnt compatible. Even the RJ5 coax cable used in the camper itself can be an issue.
I ran a seperate direct line for the reciever and a connection under wing. Just one less thing to do, Ive always wanted to hook up the dish to the camper coax to verify it woulcnt work, but by the time I get dish dialed in-no longer curious :)
One of the nice things about our 'new' tv, it accepts input from the 3 different ant sources, select on the tv which to use.