Commonly the amplifier, aka booster, is mounted to the back of a plastic faceplate similar to one for an electric wall switch, outlet, or coax. The same faceplates I've had on both RV's, one an '85 and the other our '06 Beaver, were virtually the same; the antenna coax feeds into the small amp in back, and a port next to the amp's small on/off switch on the faceplate accepts the coax cable that goes to the TV.
If the switch is off, then cable TV from a park outlet can feed through to the TV. If the switch is on, a red LED near the switch lights, meaning the amp is working to boost the antenna signal, and the park feed is bypassed.
If you can backtrack the coax from the TV, you may find its origin port and by default the plate with the switch. It was on the side of the center floor console, as I recall, with an extra 12v outlet on the old Pace Arrow. It's in the copilot's windshield overhead (audio/video) cabinet, hiding back against the curbside wall in our Monterey.
-Joel