All about Antennas

Ride the wave

Scientifically speaking, an antenna is a transducer used to convert high frequency electromagnetic current to radio waves and vice versa.  Electromagnetic waves bearing all kinds of signals-for televisions, cell phones, satellite radios-bounce around us, invisible and inaudible.

Antennas use electromagnetic fields to focus and refine the signals carried in these waves into a useable stream for any kind of receiver, such as a television, or a GPS unit. Antennas range in size from extremely small (such as a paper clip-sized antenna in a laptop computer) to gigantic (radio wave astronomy dishes over 300 feet in diameter).  Antennas, whether included or attached after purchase, improve the end performance of any electronic device that receives broadcast signals on commercial frequencies.

Beyond rabbit ears

While most home entertainment enthusiasts spend a great deal of time deliberating over the make and model of the television, few devote much mental energy to the selection, placement, or installation of an antenna, even though the antenna has as much to do with the final quality of the picture as any other part of the system. 

Outdoor placement is generally better, as outdoor antennas tend to establish a direct, line-of-sight connection to the transmitting station and interference from walls and other electronic devices is reduced.   Many manufacturers produce antennas that can be placed indoors or outdoors, giving the buyer flexibility. 

The higher one installs the antenna, the clearer and more direct the signal, but any antennae should be a placed a minimum of four feet above the structure to which it is mounted, preferably above the level of the roof.

The improvement in the quality of the antenna depends on more than just placement.  The size of the antenna makes an impact as well.  The larger an antenna, the more signal it receives. However, the shape of the antennae also makes a dramatic impact.  Engineers devote thousand of hours to perfect antennas, experimenting with materials from plastics to wood to powdered crystals.  The shape of an antenna influences the range and direction of its coverage, as well. 

For this reason, some antennas gravitate towards particular shapes:  marine TV antennas tend to be round or disc-shaped to cover the relatively small area of a boat, whereas television aerials tend to be rectilinear, to draw a signal down from the top of a building into a room.  Based on the input of a specific address, several websites offer recommendations for antenna sizes and shapes that take into account terrain, distance from transmitters, and general weather conditions.

Old dog, new tricks

Popular for televisions and radios before the advent of cable and satellite services, antennas have found more uses in recent years.  Satellite radio stations beam their signals down to specially designed receivers, the sound quality of which can be drastically improved with an inexpensive antennae upgrade.  Subscribers to HDTV services can also use inexpensive antennas to get local HDTV content from regional affiliates.  Antennas can boost wireless signals for home or business computer networks as well.

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