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[TowerTalk] Resonance of loaded Parasitic Elements

To: <towertalk@contesting.com>
Subject: [TowerTalk] Resonance of loaded Parasitic Elements
From: K7GCO@aol.com (K7GCO@aol.com)
Date: Thu, 6 Sep 2001 08:51:08 EDT
In a message dated 9/6/01 4:04:19 AM Pacific Daylight Time, n4kg@juno.com 
writes:

<< 
 A 5% lower resonant frequency for the reflector is a good place
 to start.  It seems to me that one way to do this is to split and
 insulate the reflector and then either grid dip the element or
 measure the impedance at the center.  Once it is tuned, then
 it may be joined and mounted to the boom.  Yes, there may be
 some detuning effects but I would expect them to be small for
 a 40M element.
 
 73 / GL,  Tom  N4KG
 
 On Wed, 5 Sep 2001  "K&L" <kmccourt@tbaytel.net> writes:
 > 
 > Hi All , I am in the process of building a loaded two element 40 
 > beam. I
 > have the driven element finished and its total length is 43` it is 
 > resonate
 > @ 7.150. What would the most practical way to tune the reflector be 
 > ? Should
 > I split & insulate the reflector , mount it on the boom and check 
 > the
 > resonate frequency ?  Is  5 %  longer a good length ? I am not quite 
 > sure of
 > the best way method to use .  Would like to get some input on this .
 > 
 > 73   Kevin
 > VE3KKM
  >>
I've been able to grid dip aluminum elements without cutting them.  If you 
have troubles getting a dip reorientate the coil.  Plan B is to make a shunt 
link of 1 or more turns and connect it to the element with hose clamps.  
k7gco.

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