How Does an ATSC Tuner Work?

Operations

An ATSC tuner is the official name for the standard TV tuner found inside all television sets. The basic operation of an ATSC tuner is very straightforward. The tuner takes the television signals it receives from either a cable box or an antenna and converts them from their present form into the audio and video information that can then be displayed on the TV screen. Without the tuner, a television would not be able to decode the signals being received and would then be essentially worthless.

Stations

Television stations all broadcast the same type of signal on different frequencies. We call them "channels," but in reality the difference between the signals received from ABC and the signals received from CBS are the fact that they are on different ranges of the broadcast spectrum. When you change the channel on your television, in actuality you are telling your tuner to stop picking up the signal from one frequency and to start picking up the frequency from another.

The Format

In addition to simply decoding the broadcast signal, the ATSC tuner performs the important task of formatting the image to fit your specific TV screen. For example, if the television station is broadcasting the program you are watching in widescreen and you have a standard shaped TV the tuner knows to chop the sides off of the image in order for it to fit the entire screen. Likewise, if you have a widescreen TV and are receiving a standard definition signal, it knows to (depending on your settings) add black bars to the left and right of the TV in order for you to be able to see the entire image.