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Re: [TenTec] What makes the 238 good or any other tuner good?

To: tentec@contesting.com
Subject: Re: [TenTec] What makes the 238 good or any other tuner good?
From: "Rob Atkinson, K5UJ" <k5uj@hotmail.com>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Thu, 19 Jan 2006 13:27:37 +0000
List-post: <mailto:tentec@contesting.com>
Hi Roger,

since you seem to proudly eschew the use of a tuner, I'd like to know what you call that matching network you have at the f/p of your inverted L--a feedpoint reactance remover maybe?

I modelled the loss on my run of 1/2" heliax to my 160 m. inverted L for a matching network at the f/p v. if I tuned the line to 50 j0 in the shack. I found that if I put 1 kw into the line in the shack and had the network tuning at the feedpoint, I'd gain a whopping 8 watts delivered to the antenna (well, actually 5 watts because the LC network I'm building would dissipate 3 watts), compared to if i put the network in the shack right after the tx. I decided 8 watts out of 1 kw wasn't worth going outside to the feedpoint for every qsy, or constructing a motor drive and control box for this thing.

I don't know how many antennas are actually 50 j0 at the feedpoint in a ham band without any coils, stubs, tuners, baluns etc. at the feedoint, but I'd prefer to not limit myself to them and the one or few frequencies where they are 50 j0.

73,

rob / k5uj

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