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Isotron is the trade name for a shortwave antenna marketed by Bilal Co. for use as an amateur radio transmitting antenna for restricted spaces. [1] It is physically short as compared to a dipole antenna for a given frequency. It consists of a coil placed between two angled sheet metal plates.
The ground rods create a ground plane under the antenna which increases the gain. The ground rods may extend horizontally from the base, but in antennas fed by coaxial cable as shown here they are usually sloped downward to increase the radiation resistance of the antenna from the 36 ohms of a quarter wave monopole closer to 50 ohms, so the ...
In most antennas, the radiation from the different parts of the antenna interferes at some angles; the radiation pattern of the antenna can be considered an interference pattern. This results in minimum or zero radiation at certain angles where the radio waves from the different parts arrive out of phase , and local maxima of radiation at other ...
English: Diagram of a corner reflector antenna. It consists of a half wave dipole antenna mounted in front of two flat rectangular reflectors joined at an angle θ which is usually 90°. The reflector is usually made of rods parallel to the dipole element. Corner reflector antennas have gain of 12-15 dBi, high front-to-back ratio, and wide ...
A young Polish woman with radio antennas in Åland Ham radio antenna farm in the backyard. The many facets of amateur radio attract practitioners with a wide range of interests. Many amateurs begin with a fascination with radio communication and then combine other personal interests to make pursuit of the hobby rewarding.
The rhombic antenna is a directional wire antenna used on MF and HF bands for shortwave reception. The antenna consists of a wire suspended above the ground in the shape of a rhombus , terminated at one end by a resistor equal the the wire's characteristic impedance, about 400 to 600 ohms, and at the other end connected to the feedline to the ...
[40] [36] He credited Prof. Moisè Ascoli of Rome with first calculating in 1897 that the antenna radiated at a wavelength of four times its height. [38] An integral equation for the current in wire antennas was derived by Henry Pocklington in 1897, [38] [41] who showed the current was approximately a sinusoidal standing wave.
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.)