If this is a Heartland RV, the owner's manual says
"Television Viewing
Set TV to proper reception mode – go into the menu function of the TV and select either “air” or “cable”.
Antenna – Make sure TV booster is turned on (in bedroom TV cabinet) for “air” reception.
TV booster needs to be in the off position for the park cable signal to be passed through to the TV.
Tune channel as needed.
Audio can be routed through the Audio System by turning radio to “aux” input (“FNC” button)."
I believe the OM on their website that I took this from is a "general" version for multiple unit types.