AFter re-reading again I think maybe you don't have an EXTERNAL CABLE TV connection installed on your trailer. I guess some come that way??? I'm surprised your trailer doesn't have one installed.
This should be an easy thing to add. Only a small holes goes all the way thru the wall of the trailer and come up inside a cabinet on the inside. Then just a couple of self tapping screws to hold the flip door connector to the wall. Use the RV DICOR sealant behind the outside wall connector...
The external FLIP DOOR Cable Connector looks like this

Or pay the dealer $100 to do it...
Roy Ken