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AN/FLR-9 in Elmendorf, Alaska c. 1964. The AN/FLR-9 is a type of very large circularly disposed antenna array, built at eight locations during the Cold War for HF/DF direction finding of high priority targets.
The angle of the slope is usually between 45°–60° and the lower end of the wire is at least 1 ⁄ 6 wavelength above the electrical ground. [3] A sloper is typically fed with a coaxial cable in the center, at the top of the center support mast. At least 1 ⁄ 4 of the wavelength of feedline must be at 90° angle to the antenna. [3]
The company focuses on station accessories, including antenna tuners and antenna switching equipment. MFJ was founded in 1972 by Martin F. Jue. As of 2014, the company was recognized as the largest producer of amateur radio products worldwide. [2]
A dipole can be fed from very near its end (needing to be only about 1 / 20 th of the dipole length from the actual end) but the end impedances are exceedingly high – a few thousands of ohms, depending on the average height of the antenna and thickness of its wire.
Often random wire antennas are also (inaccurately) referred to as long-wire antennas.There is no accepted minimum size, but actual long-wire antennas must be greater than at least a quarter-wavelength ( 1 / 4 λ) or perhaps greater than a half ( 1 / 2 λ) at the frequency the long wire antenna is used for, and even a half-wave may only be considered "long-ish" rather than "truly ...
It is a device, usually a resistor, used in place of an antenna to aid in testing a radio transmitter. It is substituted for the antenna while one adjusts the transmitter, so that no radio waves are radiated so that the transmitter does not interfere with other radio transmitters during the adjustments. (As no dummy load is ideal, however, some ...