Re: dish net
Actually it just depends upon how your RV is wired for the TV and the dish use. If you use a portable dish on a tripod, you can use the existing coaxial cable to send the signal to your receiver if it does not use a signal splitter to cause your cable connection to be shared by two TVs. If the cable goes from the connection to a selector switch box, you need to install the dish receiver between the input and the selector switch.
If your cable connection has no selector switch but supplies two TV sets that means that there is a signal splitter somewhere in the system. Those splitters will not pass the voltage that is sent to the dish LNB's via the coaxial cable so that would mean that you will have to run new cable. Of course, if you do it this way then both TV sets will have to watch the same satellite programing. For separate programing you would need to put in two receivers and they would each need their own coaxial cables and LNB's on the dish.
For the RV, as long as you have the proper cabling, you can just take the receiver from the house and use it in the RV when traveling. There is no need to pay for an extra receiver.