Will I Need an Antenna to Get Channels on an HDTV?

Full-power over-the-air (OTA) broadcasters in the United States completed the transition from analog to digital broadcasts in June 2009. This transition, however, only applied to the OTA signals; cable and satellite transmissions and services were unaffected, and both allow TVs with either an NTSC or ATSC tuner, including HDTVs, to continue to receive channels when connected to the set-top receiver box or directly to the wall cable outlet. As both types of providers are likely to offer the local channels also available over the air, an antenna will not be needed.

High definition is a term used to describe a video resolution consisting of at least 720 vertical lines for each frame. These frames can be transmitted in either a progressive-scan or interlaced format, creating the shorthand terms such as 720p and 1080i that describe HD video. An HDTV set has the ability to receive and display both HD and SD (standard definition) signals, and many digital OTA signals are broadcast using a process called multicasting, in which the signal carries multiple distinct sub-channels, which often include both an SD and HD version of the main channel.

An antenna is simply the tool used to allow the TV's tuner, even that of an HDTV, to receive the OTA signals available at that location. Different types of antennas can be used depending on the types of channels within range and the distance of the viewer from the broadcasting tower(s). These include indoor and outdoor antennas, UHF and/or VHF antennas, and models with or without amplification, with different variations within each type. One benefit of using an antenna is the ability to receive the local HD channels completely free of charge.

If you plan on viewing OTA broadcast channels with your HDTV, you will still need an antenna. If you subscribe to a cable or satellite provider, including those from telephone-based companies such as Verizon (FiOS) or AT&T (U-verse) or use an alternative such as free-to-air (FTA) satellite, you will not need an antenna, provided the service you select carries the local broadcast channels you wish to view.