[flybouy]

A pic of the bedroom coax plate would help. Most campers of that Era had an anterior coax to connect cable in. Inside there would be a wall plate with a coax outlet and a pushbutton to choose between OTA antenna (requires button engaged to send 12vdc to antenna amplifier ) or disengaged to choose cable.

Typically there's also a wall plate with 2 coax connectors. For normal operation there is a short cable with a male coax connector on each end. This is connected to form a loop from one coax outlet to the other in order pass the signal thru. If you connect a satellite dish to the exterior coax connecter than that coax loop would be replaced with your satellite box.