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Re: Topband: How to detune a wire Inverted L? How to 'detune'electrical

To: topband@contesting.com
Subject: Re: Topband: How to detune a wire Inverted L? How to 'detune'electrical fence
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Thu, 15 Aug 2013 13:00:13 -0700
List-post: <topband@contesting.com">mailto:topband@contesting.com>
On 8/15/2013 7:39 AM, Tom W8JI wrote:
Depending on any networks or transmission lines between the detuning switch and the element, the optimum termination at the switch might be almost anything.

If the antenna is close to a quarter wave, one rather easy termination is t make the feedline either a shorted quarter-wave or an open half-wave of transmission line. A halfwave of RG8/RG213 for 160M won't have much loss, and a simple antenna relay box (like W2VJN's 2X1 Top Ten box, which runs on 12VDC) would make it quite easy to rig. So simply add enough coax to reach either of those lengths and add the relay and control line that provides the short or open in RX mode.

The downside of this, of course, is that you can't listen on the TX antenna for diversity. .

73, Jim K9YC
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