I wanted to add to this thread simple modifications to a dish reflector antenna for RV use, transport and frequent set-up. I cannot seem to find the exact webpage I used for this info so I will just be describing some of it.
The main modification is to the antenna elevation mechanism. Please see the last page of:
http://tv4rv.com/conversion.pdf to get the general idea. I did not buy this company's kit, but instead installed the threaded rod/washer/nut along with a bracket. My dish is in my rig in storage right now, but I believe I made a simple bracket for this using a small right angle shelf bracket, drilled with a hole for the threaded rod assembly. This allows elevation to be set easily, and I don't even tighten down the antenna elevation nuts when I use the antenna.
A second modification I made (but can no longer find online) to a previous antenna is to make the rectangular LMB support arm hinged so the antenna can be folded up some for transport. To do this remove the LMB assembly from the end of the arm tube (Dish network has just 2 screws holding it), unscrew the coax cable and pull it out of the arm tube, select a point about 3 inches from the arm tube base end, and cut the tube in 2 with a hacksaw at that point. Then using a small door-type hinge and short machine screws and nuts, put a hinge on the top (LMB) side of the arm tube. Plans I saw also had a disassembled hinge on the bottom of the tube with a hinge pin you took out to fold the arm tube, and put in to use the dish, but I found that gravity held the arm down enough not to need this. Re-thread the coax cable back to the LMB, re-attach the cable to the LMB, and re-install the LMB. You now have a dish antenna where you can fold the arm tube flat against the dish reflector curve for compact storage. I used a small piece of foam rubber between the dish face and the LMB's to protect them from banging. I usually used a slightly stretched bungee cord from one reflector edge, across the folded arm tube and to the other reflector edge to hold the arm tube and foam rubber in place during travel.
My current dish has just the elevation mod. I put 2 large sheet metal screws into the exposed aluminum studs of the top of my Bighorn storage compartment, and added 2 loops of mechanics wire (one at each end of the arm tube) to the dish arm tube to hang the antenna upside down from the top of the storage compartment sheet metal screws, out of harm's way during travel.