I would second switching that old beastly tube TV out. It will still work fine on the majority of campground cable systems but so will a new HD set and the new set will have the advantage of pulling over the air from your antenna with no extra equipment needed.
There are a lot of digital channels over the air now and some are actually not bad. The picture quality on the HD ones blows away the cable as well. If you get a decent signal where you are parked, watching the game on a network TV broadcast over the air is every bit as good as HD satellite and maybe better.
Also, the new TVs are getting very thin and light. I put a cheap 24" on the overhead in our MH and it can't weigh but 8 lbs. It was so light, I just put a cheap flush mount that I picked up at Ross across the opening for the old TV and secured it with normal wood screws and lock washers. In the bedroom, I used another cheap articulating arm secured with bolts and lock nuts. The TV that was in there from the factory already had a nice strap for it built into the cabinet so that strap now holds the new tv against the cabinet when in motion.
LCD TVs use very little power so a small 12v inverter can power the new set if use while driving is desired.