Analog HF Antenna Analyser


Posted on Feb 7, 2014

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
Click here to download the full size of the above Circuit.

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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