Television Antenna - Installation

Installation

Antennas are commonly placed on rooftops, and sometimes in attics. Placing an antenna indoors significantly attenuates the signal available to it. Directional antennas must be pointed at the transmitter they are receiving; in most cases great accuracy is not needed. In a given region it is sometimes arranged that all television transmitters are located in roughly the same direction and use frequencies space closely enough that a single antenna suffices for all. A single transmitter location may transmit signals for several channels.

Analog television signals are susceptible to ghosting in the image, multiple closely spaced images giving the impression of blurred and repeated images of edges in the picture. This was due to the signal being reflected from nearby objects (buildings, tree, mountains); several copies of the signal, of different strengths and subject to different delays, are picked up. This was different for different transmissions. Careful positioning of the antenna could produce a compromise position which minimized the ghosts on different channels. Ghosting is also possible if multiple antennas connected to the same receiver pick up the same station, especially if the lengths of the cables connecting them to the splitter/merger were different lengths or the antennas were too close together. Analog television is being replaced by digital, which is not subject to ghosting.