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Re: [TowerTalk] 30m Dipole

To: "Dan Hearn" <>,"Keith Dutson" <>, <>
Subject: Re: [TowerTalk] 30m Dipole
From: Jim Lux <>
Date: Thu, 03 Aug 2006 16:28:21 -0700
List-post: <>
At 02:06 PM 8/3/2006, Dan Hearn wrote:
>Additional loss occurs in the tuner which may be greater than xmsn line
>loss. QST has had measured losses for various commercial tuners as the
>subject of 1 or more articles. The losses on low bands and certain
>impedances can be a significant factor. 73, Dan, N5AR

Which is why it's worth playing with something like XLZIZL.. (which 
calculates tuner loss)

I also note that the QST reviews don't test into a mismatched *reactive* 
load, which, after all, is MUCH more likely than a mismatched resistive 
load.  That is, you're a heck of a lot more likely to wind up trying to 
match 50-100j or 50+100j than 150+0j.  And that makes a fairly substantial 

If someone has "good" numbers for the losses of a modern relay style 
autotuner (or the Q of the reactive components), I'd love to get them.  QST 
just did loss checks on manual tuners, and checked the match range for 
autotuners into resistive loads.

I've been doing some analysis on just this, and been making sort of WAG 
approximations based on the charts in FairRite and Micrometals catalogs. 


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