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The information below is extracted from the "benchmark" 1937 I.R.E. paper* of Brown, Lewis & Epstein of RCA Laboratories, and is based on their accurately measured data for these systems. IMO, the outlined and underlined text at the bottom of this clip is worth remembering, and deserves greater access/acceptance. *Proceedings of the Institute of Radio ...


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RE (from the OP): I'm confused by having one-half of the dipole tied to the RF transmitter output and to Earth ground. Can anyone explain the electronics behind what is going on? Just to note that all antenna systems are two-terminal devices — no r-f energy will flow on one "leg" of a dipole without an equal amount of r-f energy flowing on the other leg. ...


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Welcome to the world of RF (radio frequency) and AC power, where the obvious rules of DC power don't work. In RF electronics, just because two wires are DC shorted doesn't mean they are RF shorted. In RF, a transmission line (like coax) can be shorted at one end and measure as RF open at the other end if it is an odd multiple of quarter wavelengths ...


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The part of the dipole that is connected to the shield is NOT grounded at RF. There are common-mode RF signals on the outside of the coax caused by the junction of the unbalanced coax and the balanced dipole. This is why we use choke baluns at the feedpoint: to force all the power present on the center conductor and the inside of the shield onto the dipole. ...


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