Antenna Television/Introduction

Over-the-air television is a from of broadcasting in which television signals are distributed from a transmitter via radio waves to a TV receiver with an antenna. It differs from satellite television, when signals are transmitted to a satellite dish from an orbiting satellite, or cable television, in which the signal is carried to the receiver through a cable. The picture quality for antenna television tends to be clearer than the other two methods, because the television signals are unprocessed.

The only equipment required is an antenna. Antennas are divided into two categories: indoor and outdoor. Indoor antennas are generally smaller, while outdoor antennas are larger and generally have greater receiving capability. They are also designed to handle weather such as wind, rain, and snow, unlike indoor antennas.

Available channels
A downside to over-the-air broadcasting is that channel options are far more limited than cable or satellite. They are normally restricted to local broadcast channels. Below is a list of channels that are typically available through over-the-air broadcasting, and a sample of programs they offer.

Channels and Frequency Bands
A frequency is a measure of the number of oscillations of a wave per unit of time, while a channel is a specific range of frequencies that is used to transmit information.

Following the introduction of digital TV, there are now two types of channels: virtual channels and "real" or "RF" channels. The RF channel is what a station uses to broadcast its signal, while the virtual channel is what appears on the television. Virtual channels will be followed by a period and a second number (ex. "5.1").

Terrestrial television channels are divided into two bands: the VHF band which comprises channels 2 through 13 and occupies frequencies between 54 and 216 MHz, and the UHF band, which comprises channels 14 through 36 and occupies frequencies between 470 and 700 MHz.

Antenna Gain
Antenna gain indicates how how strong a signal an antenna can receive from a specific direction. The farther away the target is, the higher the antenna's gain should be. However, with round or omnidirectional antennae, a higher gain should be avoided to ensure the signal isn't too focused and unable to reach multiple wireless locations in your household.