Balun, unun, balbal: Forskelle mellem versioner

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[[File:Tvbalun.jpg|thumb|En 75-til-300 [[Ohm|Ω]] balun som er indbygget i et antennestik.]]
 
En '''Balun''', '''unun''' eller '''balbal''' anvendes til [[audiofrekvens]]er og [[radiofrekvens]]er til elektriske [[signalkredsløb]] (incl. [[datakredsløb]]). BegrebetEn ogbredbåndet ordet ''balun'' med [[ferritkerne]]r blev første gang beskrevet i radioamatørlitteraturen i 1964 af [[radioamatør]]en Richard H. Turrin, W2IMU.<ref>Richard H. Turrin, W2IMU, "Broad-Band Balun Transformers", QST, August 1964, pages 33-35.</ref><ref>[https://www.okdxf.eu/files/balun-sevick.pdf CQ April 1994 pp. 26-46, More On The 1:1 Balun BY JERRY SEVICK*, W2FMI] Citat: "...Baluns have taken on a more significant role in the past few decades with the advent of solid-state transceivers and Class B linear amplifiers, which have unbalanced outputs...R. Turrin, W2IMU — 1964. The first presentation in the amateur radio literature on 1:1 baluns using ferrite cores was by Turrin in 1964.10 Turrin, who was a colleague of Ruthroff at Bell Labs...", [https://web.archive.org/web/20181012084555/https://www.okdxf.eu/files/balun-sevick.pdf backup]</ref>
 
Baluner, ununer og balbaler har en eller flere af disse formål:<ref name="pacarc">[http://www.pacarc.org/pdf/k0s_field_manual.pdf pacarc.org: Antenna & Transmatch Evaluation Field Manual. Official Guide for the Strange Antenna Challenge] Citat: "...Baluns are actually a small family of devices: balun, balbal, or unun. These all refer to the whether you desire to move between balanced (ladder line) to unbalanced (coax) transmission line (bal-un), between balanced and balanced line (bal-bal), or between unbalanced and unbalanced line (un-un). I will usually refer to all of these with the generic term “balun.”...The most common baluns are 1:1 (one to one) and 4:1. Baluns are a form of transformer, either changing voltage or current by a given ratio...Properly terminating balanced line is important...You may also place a “bal-bal” at the antenna feedpoint. This will adjust the impedance...Connecting your balanced line to a single coax transmission line will require a balun...", [https://web.archive.org/web/20180902084028/http://www.pacarc.org/pdf/k0s_field_manual.pdf backup]</ref><ref name="QEX">[http://kambing.ui.ac.id/onnopurbo/orari-diklat/teknik/balun/qx3Trask.pdf QEX Mar/April 2005: Designing Wide-band Transformers for HF and VHF Power Amplifiers] Citat: "...The three forms of transformers that are encountered, unbalanced-to-unbalanced (unun), balanced-to-balanced (balbal), and balanced-to-unbalanced (balun), are used in various combinations to accomplish the desired goals...[Illustrationer:] Fig 22—Three-conductor twisted-wire transformer configurations...", [https://web.archive.org/web/20170821211806/http://kambing.ui.ac.id/onnopurbo/orari-diklat/teknik/balun/qx3Trask.pdf backup]</ref>