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Re: Topband: Antenna analysers in close proximity to BC station

To: "Tom Boucher" <tom@telemetry.demon.co.uk>, "160 reflector" <topband@contesting.com>
Subject: Re: Topband: Antenna analysers in close proximity to BC station
From: "Tom W8JI" <w8ji@w8ji.com>
Reply-to: Tom W8JI <w8ji@w8ji.com>
Date: Mon, 5 Nov 2012 07:59:23 -0500
List-post: <topband@contesting.com">mailto:topband@contesting.com>

Thinking again about this, we have missed out a stage. After measuring the tuner output impedance, we need to make a temporary L network which, when terminated with 50 ohms, looks like the antenna. Now put the MFJ on this terminated network and measure it's R +/- jX values which will represent the antenna.

Networks with loss are not always bilaterial.

Since tuners have unevenly distributed losses, they are not bilaterial.

If I adjust a typical tuner for 1:1 SWR into 50 ohms and reverse it, the new input impedance will not be 1:1 SWR.
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