There are two things often confused with being a splitter. One that has already been mentioned is the "seperator" which is used right behind the reciever. It has what it is printed on it. The single side of the seperator connects to the cable leading to the dish. The other two sides connect to input 1 and input 2 ports in the back of the reciever.
The other item confused with a splitter is a diplexer. This allows the output from the TV2 port on the back of the receiver to travel back through the primary cable coming in. It runs through the cable to another diplexer somewhere, and there it exits to a cable going to TV2....clear as mud, right?
Look at the "splitter" in question and read the lettering on it. You may see the single side port called "in/out," and on the other side one port may say "VHF/UHF" and the other "SAT." If it reads similar to that, it is a diplexer.
Here is the basic hookup using diplexers (2.)
The cable coming from the dish will at some point connect to the SAT port of a diplexer. It may be outside, in an attic, or in a basement. From this diplexer, a cable from the UHF/VHF port will run to TV2, and a cable from the IN/OUT port will run to where the reciever is. Now, in the room where the receiver is, the able comes in and must connect to the IN/OUT port of another diplexer. From this diplexer, a short cable from the SAT port will screw into the single side of the seperator. Also on this diplexer, there is a short cable from the UHF/VHF port to the TV2 (home dist) port on the back of the receiver.