the first thing to make sure is that you have a digital TV or a digital converter if not. assuming you have that, since it worked in another RV. there should be a Antenna booster located in the RV somewhere, usually in the bedroom.
Most airlines in the United States, including American, Delta and United, allow carry-on bags that are no more than 22 inches long, 14 inches wide and nine inches high. Southwest and JetBlue accept a more generous 24 inches by 16 inches by 10 inches, and JetBlue even adds a couple more inches for cabin bags flying on its Airbus A320 planes.
Delta Airlines (DL) will charge $200.00 USD extra for bags that are from 63 to 115 linear inches or from 160 to 292 centimeters on U S domestic flights. Bags greater than 115 linear inches or 292 centimeters will not be accepted as checked baggage / hold luggage.