Question on Television wiring in my 5th wheel

So much confusing info being posted here. As you read above you will see RG50 again, I assume RG59 was the intended number. Don't let the numbers get you off track. Whatever coax is in your coach "would" work to carry the satellite TV signal. The problem is that the manufacturer wired your coach for Cable TV and not Satellite TV. The 2 services are not compatible or interchangeable. However, depending upon how your coach is wired, you might be able to modify the wiring to work with either Cable TV or Satellite TV (but never both at the same time). Do you have a video control center in the coach were you have a black box with a bunch of buttons labeled Ant, Cable, VCR, etc.? If so, the cable connection comes into the back of this box and the signal is then sent to the various TV's. If you don't have one of these, the chances of being able to modify your cable connection is pretty low. What you would be looking for is a wall plate with a tiny button or slide switch and a tiny LED. When the light is on you can watch OTA TV and when it is off you can watch Cable. If it's a direct run to this box before being split you can modify that connection. If it's not a direct run you cannot.
Let us know what you have in your coach and I can get you some additional details.
Once you have a working incoming satellite signal a standard receiver has only one output so all TV's could watch the same 1 satellite channel. Dish also makes a dual tuner box which would allow 2 TV's to watch 2 different channels but only one could be in HD.