Fellow listees,

I do see recenly many motorhomes, trailers equipped with satellite TV antennaes-dish. But some owners simply have tripods with dish on top. The tripod with a vertical pipe about 3 -4 feet just rests on the ground. The owners , I've seen, did use some kind of device to adjust the dish position exactly for perfect reception.
I am more inclined to have the dish mounted on my Westy's roof  above the driver and folded down when not in use. 
Here are the questions:
Did anyone attempt to install the dish antennae on Westy? What size of the dish is preferable ? What type, kind, model of a device-instrument is good for dish adjustment? Will the raised roof affect the reception if the dish is installed right above the driver? 
If somebody did the installation, can I get a description and installation pictures? 
Thanks in advance.

Ark Mirvis (the heaterman)