Antennas and Their Uses

Antennas have been around for a very long time. The two most common types of antennas that we encounter frequently are the TV antenna and the radio antenna. Antennas are used to transmit and receive electromagnetic waves. Without an antenna, our TV and radio sets would not be able to pick up a signal from the stations. The number of channels that your television set is able to show depends on the strength of the antenna and how the signals are able to pick up. The location of the antenna, its quality and weather can affect the quality of the transmission as well as how many stations your device will be able to pick up.

Television Antenna

A TV antenna is specially designed to receive signals that are usually transmitted at frequencies of 41 to 250 MHz in the Very High Frequency (VHF) band, and 470 to 960 MHz in the Ultra High Frequency (UHF) band in the different countries around the world. Various antennas are designed differently. They consist of several conductors that have different lengths and these correspond to the wavelength range that the antenna is designed for. In order for an antenna to work, it has to be used together with a tuner that is included with TV sets.

TV antennas can be indoor or outdoor. An indoor antenna, also called half-wave dipole antenna, is usually small in size. They have "ears" that can be adjusted in lengths to improve signal. However, these antennas are not as good as those that are mounted onto rooftops or outdoors. Outdoor antennas are generally bigger and are able to receive better and more signals. The problem with these antennas is that it can be easily affected by the weather. For example, if there is strong wind blowing outside, it can change the position of the antenna that would disrupt the signal. To overcome the problem about weather, you can mount the antenna on the highest window in the building or on the attic. This can ensure good quality signal and prevention of disruption of signal. The downside of outdoor antennas is that they can be relatively expensive. Another factor that affects the quality of the signal that you receive is your location relative to the transmitter. If you are located close to the transmitter, the signals that you would receive would definitely be of better quality.

Radio Antenna

How a radio antenna works is the same as a TV antenna. It is a device that changes electric currents into radio waves and vice versa. Like TV, it has a transmitter and a receiver. The signals are transmitted when the transmitter applies radio frequency current to the terminals of the antenna which radiates this energy as radio waves that can also be known as electromagnetic waves. For reception, the process is similar as the terminals detect the signal and receiver decodes it to be amplified.