In fact, in most RVs, the park cable input does not go to the amplifier control, but directly to the video switch box. Only some models have the Winegard system, ours and most that we have seen in our rving have not had the Winegard system. If you have an input on your video switch box labeled Cable or possible Aux, that's where the park cable connection goes.
The OP didn't say they wanted to connect a satellite antenna, in fact, they said they didn't have any need for satellite, but were putting up an external TV antenna for HD TV. Mentioning satellite is just confusing the issue.