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  2. Balun - Wikipedia

    en.wikipedia.org/wiki/Balun

    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 ...

  3. T2FD antenna - Wikipedia

    en.wikipedia.org/wiki/T2FD_antenna

    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.

  4. Dipole antenna - Wikipedia

    en.wikipedia.org/wiki/Dipole_antenna

    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 ...

  5. Antenna feed - Wikipedia

    en.wikipedia.org/wiki/Antenna_feed

    A balun is a transformer that couples between balanced and unbalanced transmission line components. For example, to feed a dipole antenna from an unbalanced feedline like coaxial cable, the feedline is connected to the antenna through a balun. Without the balun, the unbalanced part of the current will flow on the outside of the coaxial cable ...

  6. Random wire antenna - Wikipedia

    en.wikipedia.org/wiki/Random_wire_antenna

    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 ...

  7. Twin-lead - Wikipedia

    en.wikipedia.org/wiki/Twin-lead

    For this reason, when attaching a twin-lead line to a coaxial cable connection, such as the 300 Ω twin-lead from a domestic television antenna to the television's 75 ohm coax antenna input, a balun with a 4:1 ratio is commonly used. Its purpose is double: First, it transforms twin-lead's 300 Ω impedance to match the 75 Ω coaxial cable ...

  8. Antenna tuner - Wikipedia

    en.wikipedia.org/wiki/Antenna_tuner

    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 ...

  9. G5RV antenna - Wikipedia

    en.wikipedia.org/wiki/G5RV_antenna

    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 frequencies require a transmatch. [citation needed] There are many variants of the G5RV antenna. Two variations of the G5RV design, called ZS6BKW ...