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.
For Travel Through April 3, 2017: Personal item (e.g., purse, small backpack, etc.): Dimensions must not exceed 16 x 14 x 12 inches (40 x 35 x 30 cm) including handles and wheels. Carry-On 10 x 18 x 22. Carry-on bag: Maximum of 22 x 18 x10 inches (56 x 46 x 25 cm) including handles and wheels. We may require that a carry-on bag travel as a checked bag if it cannot be safely stowed on a particular flight. Checked bags: Maximum of 62 linear inches (length + width + height; 158 cm) including handles and wheels and maximum of 40 pounds in weight (18.1 kg).