Let's take a second and clarify a common misconception about satellite antennas:
Although a dome antenna can lock onto up to 3 satellites in an arc, that's merely automatically locating where it has to turn, in order to receive each satellite. It can only receive all the channels from one satellite at a time -- and has to move its single LNB assembly to change satellites.
A parabolic dish antenna has a multiple LNB assembly to receive all 3 satellites simultaneously without moving. When you change between satellites on a parabolic dish, there's no movement and you can even watch different channels on different satellites on both your TV sets, all at the same time.