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Occasionally, mechanical and electrical tilt will be used together in order to create greater beam tilt in one direction than the other, mainly to accommodate unusual terrain. Along with null fill , beam tilt is the essential parameter controlling the focus of radio communications , and together they can create almost infinite combinations of 3 ...
A radio mast base showing how virtually all lateral support is provided by the guy-wires. The terms "mast" and "tower" are often used interchangeably. However, in structural engineering terms, a tower is a self-supporting or cantilevered structure, while a mast is held up by stays or guy-wires. [1] A mast
A half wave whip antenna (length of ) has somewhat higher gain than a quarter wave whip, but it has a current node at its feedpoint at the base of the rod so it has very high input impedance. If it was infinitely thin the antenna would have an infinite input impedance, but the finite width gives typical, practical half wave whips an impedance ...
A guyed mast is a tall thin vertical structure that depends on guy lines (diagonal tensioned cables attached to the ground or a base) for stability. The mast itself has the compressive strength to support its own weight, but does not have the shear strength to stand unsupported or bear loads.
There are several ways of feeding a mast radiator: [6] Series excited (base feed): the mast is supported on an insulator, and is fed at the bottom; one side of the feedline from the helix house is connected to the bottom of the mast and the other to a ground system under the mast. This is the most common feed type, used in most AM radio station ...
Cellular lattice tower A cell tower in Peristeri, Greece. A cell site, cell phone tower, cell base tower, or cellular base station is a cellular-enabled mobile device site where antennas and electronic communications equipment are placed (typically on a radio mast, tower, or other raised structure) to create a cell, or adjacent cells, in a cellular network.
Similarly over a resistive earth ground, the gain will be lower due to power absorbed in the earth. As the length is increased to approach a half-wavelength ( 1 / 2 λ) – the next resonant length – the gain increases some, to 6.0 dBi. Since at this length the antenna has a current node at its feedpoint, the input impedance is very ...
Counterpoises are typically used in antenna systems for radio transmitters where a good earth ground connection cannot be constructed.. Monopole antennas used at low frequencies, below 3 MHz, such as the mast radiator antennas used for AM broadcasting, require the radio transmitter to be electrically connected to the Earth under the antenna; this is called a ground (or earth).