Lkin, on units with only a single coax input, that input is normally wired to the back of the antenna booster control plate. It looks something like this:
It's the "Cable In" in this picture:
In order to use it with Satellite, you have to disconnect it from the plate (which contains a splitter) and wire it directly to the back of your Sat receiver.
Our Library contains a method that one person used to do this: http://www.forestriverforums.com/for...?do=file&id=97
If your Sat receiver has a modulator (coax) output, you can also distribute the signal to other TVs at the booster control plate. This diagram gives you the idea: