If you have satellite TV service but want to connect multiple receiver boxes to one satellite dish, you can solve this problem with a satellite splitter. This is a very simple device that will take the signal transmitted from one RF coaxial cable and allow you to send it to multiple receivers connected by similar cables. But you need to make sure it is a satellite splitter and not meant for other signal transmission like VHF/UHF. Multiple types of satellite splitters are available. The one you'll need depends on the number of devices you are linking.
Make sure you have a satellite-grade splitter. Many of the common splitters designed for cable TV and other formats will not work in splitting a satellite TV signal. Consult an expert at your electronics store to find a splitter that will work with your satellite service.
Attach the splitter to the cable directly connected to the satellite dish outside (the cable that comes out of the wall). You must connect this cable to the splitter port that says "IN" or "SAT IN." Make sure you have the right splitter for the number of units you are connecting.
Get a simple two-way splitter if you're linking only two receiver boxes. On this splitter, the "IN" port for the dish cable should be the single port on one side. The two ports on the other side connect to your two receiver boxes.
Look for a four-way splitter if you need to connect more than two boxes. This splitter has five coaxial ports, and the "IN" port should be the middle one on the side that has three ports. The other four connect to your receivers.
Use a four-way multiswitch if you are linking satellite dishes with separate low-noise blockers, or if you want to attach an antenna for your local air channels. On the side with three ports, the dish(es) connect to any of the two end ports while an antenna connects to the middle one. The four ports on the other side are for the receivers.
You can also get a similar device, called a "combiner," if you have only one receiver and want to attach a stronger antenna to the TV for local channels. It has three ports that should be labelled. Connect the antenna to the "ANT" port and the receiver box's cable (not the dish's) to the "SAT" port. The third port connects to the TV. Make sure you have plenty of coaxial cable since you are probably connecting devices that are distant from one another.