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Re: [TowerTalk] Link Coupled Tuner Question

Subject: Re: [TowerTalk] Link Coupled Tuner Question
From: Joe Giacobello <>
Date: Sun, 19 Mar 2006 11:33:35 -0500
List-post: <>
Peter, thanks for the input.  And Cebik also suggested 1700 pF or so as 
a starting point for the 160M link.  I am currently using a 3" coil with 
five turns cut out of the center as the link.  It's not as effective as 
a concentric link, but the SWR is very responsive to the output 
capacitor and I do see 50 ohms and about zero reactance at the tuner 
input.  It occurred to me that the link capacitor was added to the early 
link tuner designs as a refinement, and I'm wondering if, with my 
particular combination of component values, a link capacitor is 
necessary at all.

Nevertheless, thanks for confirming that it tunes fairly flat. That 
gives me the confidence to go forward.

73, Joe

Peter Chadwick wrote:

>K2XX asks: Is this relative insensitivity for the series link typical?
>The usual 'rule of thumb' is that the link should be the same reactance as the 
>transmission line, or about 50 ohms. This will tune with about 1800pF on 160, 
>and will have a Q of around 1, so you can expect it to tune fairly flat. You 
>do want a fairly tight coupling between link and tuned circuit, though.
>Peter G3RZP
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