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A balun / ˈ b æ l ʌ n / (from "balanced to unbalanced", originally, but now derived from "balancing unit") [1] is an electrical device that allows balanced and unbalanced lines to be interfaced without disturbing the impedance arrangement of either line. [2] A balun can take many forms and may include devices that also transform impedances ...
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The balun is a 16:1 ratio, thereby transforming the 50 Ω (ohm) coax to an 800 Ω feed at the antenna. The resistor load is also 800 Ω, non-inductive. This allows the antenna impedance to swing from 400–1,600 Ω over the frequency range intended and thus keep the SWR at the transmitter 2:1 or lower.
The Beverage antenna or "wave antenna" is a long-wire receiving antenna mainly used in the low frequency and medium frequency radio bands, invented by Harold H. Beverage in 1921. [1] It is used by amateur radio operators, shortwave listeners, longwave radio DXers and for military applications.
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 ...
A current balun uses a transformer wound on a toroid or rod of magnetic material such as ferrite. All of the current seen at the input goes into one terminal of the balanced antenna. It forms a balun by choking common-mode current. The material isn't critical for 1:1 because there is no transformer action applied to the desired differential ...
[9] [better source needed] A length of at least 20 metres (66 ft) of 75 Ω (50 Ω) cable is recommended for operation without a balun. [10] [11] A transmatch (antenna tuner) is not required to use this antenna near its nominal design frequency of 14 MHz, and judicious length adjustments can sometimes include one other frequency band. All other ...
Transformers, autotransformers, and baluns are sometimes incorporated into the design of narrow band antenna tuners and antenna cabling connections. They will all usually have little effect on the resonant frequency of either the antenna or the narrow band transmitter circuits, but can widen the range of impedances that the antenna tuner can match, and/or convert between balanced and ...