The United States government made a mandate that all television sets sold in the country after March 1, 2007 had to have a built-in ATSC tuner. This was a precursor to the change in transmission the Federal Communication Commission (FCC) was preparing for. High definition television (HDTV) would soon replace analog signals and was increasingly being incorporated through the following years. Analog TVs could not display programming that came over on a digital signal except through a cable or satellite connector. The analog technology could not convert the digital signals without a built-in ATSC tuner.
While digital signals produce a high definition picture, a special HDTV is needed to see the details and contrast provided by high definition signals. The ATSC tuner breaks down the signal into analog bits to be viewed on a standard definition television set. As the digital signals become more ubiquitous, TV viewers needed to be able to watch those shows that were sent via digital broadcast. The picture appears with the same picture quality as it did from analog signals.
Digital versatile device players, better known as DVD players, also come equipped with a built-in ATSC tuner. Most often DVD players act as a conduit for the broadcast signal to reach the TV and so must be prepared to translate the digital signal as well. Recordings of high definition broadcast cannot be completed on a recording unit not set up for digital transmissions.
Prior to the complete changeover to digital television broadcasting, ATSC tuners also were used to translate analog transmissions into digital broadcasts for television sets that were equipped for high definition.
As of February 17, 2009, even the built-in ATSC tuner won't be enough to translate the digital signals that are mandated by Congress for all broadcasters. Without an additional high definition tuner in a separate unit or in a cable or satellite box, no signal will reach the viewer. The built-in ATSC tuner will be a redundant device following the FCC change in broadcast signal. All standard definition televisions without an external source of translating the digital signals (such as cable or satellite) must also utilize an additional external ATSC tuner just to get the signal from the antennae to the box. The internal built-in ATSC tuner will become obsolete as television manufacturers only produce high definition capable units.