Digital/Analog Coax

Wire doesnt know the difference , analog vs Digital, neither does the antenna. If you are not getting a usable signal digital does have the annoying tendency to not allow any viewing in fringe areas, whereas analog would let you watch a snowy picture. But if old cable, (or an old antenna) has corroded fittings or a poorly designed unit it will perform equally poorly with both digital and analog signals.
Are you using the same TV? Some do better with weaker signals. Your Dish system should work equally well with either RV but view of the sky and TV quality will vary.