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Those RTs with power settings can vary transmission range from approximately 200 meters (660 feet) to 10 kilometers (km) (6.2 miles). Adding a power amplifier increases the line of sight (LOS) range to approximately 40 km (25 miles). (These ranges are for planning purposes only; terrain, weather, and antenna height can affect transmission range.)
An antenna rotator (or antenna rotor) is a device used to change the orientation, within the horizontal plane, of a directional antenna. Most antenna rotators have two parts, the rotator unit and the controller. The controller is normally placed near the equipment which the antenna is connected to, while the rotator is mounted on the antenna ...
This Royal Navy model is typical of B–T goniometers. The two sets of field coils and the rotating sense coil are visible.. A Bellini–Tosi direction finder (B–T or BTDF) is a type of radio direction finder (RDF), which determines the direction to, or bearing of, a radio transmitter.
A reconfigurable antenna is an antenna capable of modifying its frequency and radiation properties dynamically, in a controlled and reversible manner. [2] In order to provide a dynamic response, reconfigurable antennas integrate an inner mechanism (such as RF switches, varactors, mechanical actuators or tunable materials) that enable the intentional redistribution of the RF currents over the ...
An NVIS antenna configuration is a horizontally polarized (parallel with the surface of the earth) radiating element that is from 1 / 20 th wavelength to 1 / 4 wave above the ground. The optimum height of such an antenna is about 1 / 4 wavelength, and high angle radiation declines only slightly for heights up to about ...
An antenna tuner, a matchbox, transmatch, antenna tuning unit (ATU), antenna coupler, or feedline coupler is a device connected between a radio transmitter or receiver and its antenna to improve power transfer between them by matching the impedance of the radio to the antenna's feedline. Antenna tuners are particularly important for use with ...
An antenna such as the one described above is usable for both local and medium-long-distance communication across a frequency range of about 1:6 . For example, an antenna for the lower portion of shortwave (say, 3–18 MHz) will be roughly 33 m (110 feet) long, with conductors spaced 1 m (3.3 feet). For the higher portion of shortwave (5–30 ...
Moxon antenna for the 20-meter band.The antenna is the faint rectangle of wires held in tension by the bent X-shaped support frame. Moxon antenna for the 2-meter band. The Moxon antenna or Moxon rectangle is a simple and mechanically rugged two-element parasitic array, single-frequency antenna. [1]