Analog HF Antenna Analyser

  
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Results are shown on an analog VSWR meter. The design was originally published in `Break-In`, New Zealand`s amateur radio magazine in Sept/Oct 2005, and is republished here with the permission of the editor. Note: `Break-In` is a term used in amateur radio to describe a system which allows another person`s signal to be heard in the brief
Analog HF Antenna Analyser - schematic

intervals between transmitted Morse Code symbols. Like many hams, I`ve been playing with antennas for years. Much of that experimentation has been, in hindsight, somewhat hit and miss, relying mainly on SWR meters and grid dip meters. When I built an RF noise bridge (See Reference 1 - Note: All references are found at the bottom of this page), the resulting impedance measurements were a major advance, but it required a full coverage receiver and considerable analysis with a programmable calculator or PC before useful information was obtained. Recent attempts to build a compact multi-band HF antenna required more careful measurements of antenna impedance. I briefly considered buying one of those commercial antenna analysers frequently advertised these days. Glancing at the cost, I innocently thought Just how hard would it be to build something like that  Casting wisdom to the winds, and with a little free time out from my regular jobthis, and a subsequent digital antenna analyser (described here ), were produced. An antenna analyzer is a device which measures the impedance of an antenna. The first, described in this article, is an all-analog device, with not a microprocessor in sight. The second, described elsewhere on this website, is a fully fledged digital meter complete with LCD display. Both cover the full 3 30 MHz HF range. The analog analyzer, as you`ll see from the photograph, is quite small. Powered with a...



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