Knowledge Base

The antenna range, expressed in miles, denotes how far from the TV transmitter the antenna can receive clear TV stations. Antenna range is more of a marketing term than a technical parameter. It gives some indication of the ability to receive high power transmissions from towers with direct line of sight from the antenna at a defined height above ground (equal to rooftop mounting or higher) and with a certain amount of radiated power. At long distances, the height of the transmitter tower has to be sufficient to overcome the curvature of the Earth. If these conditions are not met, additional losses have to be calculated that reduce this practical range, meaning an antenna rated for 100 miles may have to be de-rated to 70 miles when other factors such as terrain or other obstacles are encountered. Outdoor antennas usually perform better because normally they have higher gain and are installed at or above the rooftop, to meet free space receiving conditions.