Sarge,
I've spent many hours looking for splitters in pre-wired homes when doing sat system installs. The "old school" folks are having a hard time coming up to speed on sat technology. Having a splitter in a multi room install causes very strange symptoms and can have you pulling your hair out trying to figure out what's wrong.
Sooo... for the folks wanting to install the system thenselves, remember -
There is NO WAY to split a single LNB sat signal. The reason is the way the dish is polarized to pick up different transponder signals. A single LNB can only be polarized one way at one time. If two different sat receivers want two different transponders at the same time that have opposite polarization, you're screwed.
Thats why the later dishes all have "dual" LNBs. with two LNBs, they can be polarized differently and each pick up different transponders. This works great for up to two sat receivers. Each receiver can have it's own LNB.
BUT... what happens when you have 3 or more receivers? 3 or more receivers need a device called a "multi switch". A multi switch is very much like the old telephone switchboards. Since there are only 2 ways to polarize a TV sat dish and you have 2 LNBs, all you need is the 2 LNBs polarized opposite and a switch to connect the receivers to the correctly polarized LNB. The receivers do this by putting 13 volts DC or 18 volts DC on the cable going to the multi switch (or dual LNB in non multi switch tandem receivers) so the switch knows which LNB to connect the receiver to. The recievers down load a transponder table from the sat when they first power on so they know which transponder corresponds to which TV channel you request.
Clear as mud eh? Works great though, I'll never go back to the outages and crappy pictures I had with cable TV.