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.
However, make sure your carry-on bag is of a size permitted by your airline. Dimensions vary from airline to airline. These two legacy carriers allow each passenger one carry-on bag, and one personal item. In both cases, the carry-on bag must be no larger than 22 inches long, 14 inches wide and 9 inches high. US Airways also stipulates a maximum weight of 40 lbs. Delta says the carry-on bag must fit easily into its carry-on baggage gauges, located close to airport check-in desks. The gauges' dimensions are those of the largest permitted carry-on bag. Personal items allowed in addition to a carry-on bag include a briefcase, purse, laptop bag, camera bag or diaper bag.