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Re: [TowerTalk] Fwd: Insulated elements, Yes - No?

Subject: Re: [TowerTalk] Fwd: Insulated elements, Yes - No?
From: "L L bahr " <>
Date: Tue, 5 Aug 2014 21:54:40 -0400 (EDT)
List-post: <">>
This brings up a big question in my small mind.  Assuming you need to correct 
element length,  I can see you can use SWR to adjust the driven element.  But 
how do you correctly know how to correct or adjust the reflector, or for that 
matter any parasitic element?  During the Dark Ages when I first got licensed, 
you just made the reflector around 10% longer then the driven element.  How do 
you do it in 2014?  (I really don't want to think of remote field strength 
measurements while adjusting the parasitic element.)  If you correct the driven 
element by 1 inch to lower the SWR, do you then just adjust the reflector by 
the same amount?
Lee, w0vt

Insulating the elements will certainly reduce the correction for the
boom and mounting plate, but does not eliminate corrections completely.
There is still a proximity effect, which will obviously be greater for a
mounting that uses thin insulating sleeves than it would be if the
element is spaced farther away from the metalwork on  substantial
insulating blocks.

Corrections for element mountings are subject to some uncertainties, so
it is always preferable to use a mounting method that involves smaller
correction in the first place.

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