How Does an HDTV Tuner Work?

The Basics

An HDTV tuner works in a very straightforward manner. It takes television signals received either via an antenna or a cable box and turns them into audio and video information that can be understood by and displayed on your television set. Television information is changed into a format that is unrecognizable by a TV for broadcasting, and without a tuner to decode it the TV would not be able to understand these signals.

TV Stations

TV stations all broadcast their programs on different frequencies. What we know as different "channels" are simply different frequencies that differentiate between stations like ABC and NBC. When you change the channel on your TV, in reality you are simply telling your HDTV tuner to start picking up signals that are being broadcast on a different frequency than the one it is currently receiving from.

Reformatting

An important job of your HDTV tuner is to reformat the image to fit your particular screen. Sometimes an image is broadcast for widescreen televisions, but your TV may have a standard aspect ration. The HDTV tuner will take the widescreen image, chop of the sides, and display it to the point where it takes full advantage of your television screen.