2wheelluge - Sounds to me like "Orion_42" answered your question. Your model will be different than mine, but my model also has one of the cables go to the external co-ax connection for a possible campground signal and the other goes to the roof antennae. Both are connected at a "Y" connector (probably called a splitter) that then goes to the signal booster. From the signal booster there is a co-ax feed to the TV. If I connect to a campground signal, I have to shut off the sigmal booster.
My unit came from the factory with a 19" analog TV and I was able to remove the retaining wood block and roll-up door to remove the TV. I then inserted a false floor (1/2" plywood) including a mounted swivel. Then used the wood block to hold the false floor in place. I then fit a 19" flat panel digital television to the swivel mount.
Swivel mount is something like this, but it is mounted on my false floor and not to the wall -
