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Re: [TowerTalk] tuners and power rating

To: towertalk@contesting.com
Subject: Re: [TowerTalk] tuners and power rating
From: Steve Hunt <steve@karinya.net>
Date: Tue, 30 Nov 2010 12:29:46 +0000
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
The most comprehensive calculator I know is Owen's at:
http://vk1od.net/calc/tl/tllc.php

A good test for a calculator is to look at the loss it predicts for 10ft 
of 50 Ohm coax at 3.5MHz with a 150+j0 load (VSWR=3:1); the loss should 
be about **half** the matched loss.

Charts which imply - without any caveats - that a particular value of 
VSWR always adds a fixed "excess loss", are misleading and show a lack 
of understanding of the loss mechanisms.

73,
Steve G3TXQ

On 30/11/2010 00:04, Rik van Riel wrote:
>
> After some searching around the web, I found an online
> transmission line calculator that does take these things
> into account:
>
> http://www.stroobandt.com/antennas/tl-calculator.html
>
> It does indeed give interesting and different answers
> than the coax calculator I used before...
>
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