What Is a TV Repeater?by Gina Poirier
Those crystal-clear HD pictures with surround sound that many people enjoy on their flat-screen TVs take bumpy rides between the locations of their original broadcasts and their final destinations. TV signals needed to be "repeated" so they can be transmitted clearly over long distances to multiple locations. Repeaters are the devices that move the signals between legs of their journeys.
In modern electronic communications, a repeater is a device that receives a signal and then sends it somewhere else. In other words, it "repeats" information such as audio and video signals to another receiver. For TV, different types of repeaters transmit both analog and digital signals, although analog signals are becoming more obsolete in the industry. They send and receive signals wirelessly or through cables.
How Repeaters Work
The purposes of both wireless and cable repeaters is to transmit signals over long distances in order to overcome attenuation (signal loss) and to filter out extra electromagnetic "noise." A "repeated" digital TV signal should have clear audio and video at its final destination. A repeater with a wireless receiver picks up transmitted electromagnetic signals of a particular frequency. Then, depending on what type of repeater it is, it may convert those signals into a different frequency and filter out unnecessary electromagnetic noise. It transmits filtered signals to another receiver either wirelessly or via cable. A repeater that receives signals through a cable also filters out any distortions, restores the original signal and sends it forward.
Types of Repeaters
Repeaters are used in several ways in the TV industry. One way is over cable transmissions. Cable companies have to place repeaters between about every 6,500 to 20,000 feet of cable. Another way is in satellite communications. Satellite dishes, although more frequently called transponders, act as repeaters. Finally, there are a variety of repeaters designed for consumers who want to transmit TV signals to various places in their homes or offices.
If you are an average private consumer of TV, you probably receive your broadcast through some type of repeater, whether it be through a cable company, a satellite dish, or from a public broadcasting tower. If you have a satellite dish, it converts the powerful high-frequency TV signals into a format that your TV receiver can handle. If you have a cable or satellite receiver box, it is also a type of repeater, which sends the signals it receives to your TV through cables. You may also have additional repeaters that send the TV signal from your box to TVs in different rooms in your house. Some people extend multiple cables throughout their homes, but others now use small consumer wireless repeaters designed for short distance transmissions.