Television Antenna. A television antenna is an omnidirectional antenna tuned to the broadcast frequencies assigned to television...

Television Antenna

A television antenna is basically a low tech item. It has a series of elements cut to specific lengths that are related to the frequency of the signal it is designed to receive. Each element is a pair of metal (usually aluminum) rods sticking out from the boom.

The real difference between one brand and another, assuming similar gain and front to back ratio, will be how well anodized the metal is and quality of construction. As the metal oxidizes and the rivets rust the active elements lose contact and the performance suffers. Antennas do 'wear out' with age if they are mounted outdoors. Indoors they will last a lot longer.

Antennas are available for VHF, UHF, or VHF/UHF. If you don't need to receive UHF channels (the ones above 13) off air then don't waste money on a VHF/UHF combo. The FM radio band falls between channels 6 and 7 on the VHF band so a VHF antenna will usually work for FM as well.

There are also 'channel cut' antennas. These are antennas specifically designed to receive one channel. They are sometimes used by cable companies to pick up local stations. A large electronics supply house should be able to get them for you. The only use for one of these in a home set up is in the case of a single station located in a different direction from all the others that is difficult to pick up. You might use a two antenna set up (see below) in that case. Directional FM antennas are a variation of a channel cut antenna designed to pick up the FM band.

Television antennas are directional. They should be pointed at the transmitter of the station you are trying to receive. That is the purpose of having a rotator. In case you don't know the tips of the elements need to be angled toward the transmitter. Think of the elements as "V"s with the twin top of the V aiming towards the source.

Antennas have a specification called 'gain'. This is a measure of how well the antenna will 'pull in' a signal at a specific frequency. There is another specification called front-to-back-ratio. That is how much better the antenna receives a signal coming from the direction the antenna is pointed compared to a signal coming from the opposite direction. Front to back ratio is what makes an antenna directional. Many antennas do not have these specifications on the box or in the literature. If you see these specifications just remember that generally the larger the number the better, but since these measurements are affected by frequency you may not be able to compare between two different manufacturers numbers. Generally the bigger the antenna and the more elements the higher the gain and front to back ratio. Keep in mind though that a combination VHF/UHF/FM antenna will have more elements than a UHF only or VHF only antenna of the same gain.