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[TowerTalk] Cushcraft A-3 WS with 30 meter kit-PROBLEM (update)

To: TOWERTALK@contesting.com
Subject: [TowerTalk] Cushcraft A-3 WS with 30 meter kit-PROBLEM (update)
From: Cqtestk4xs@aol.com
Date: Sat, 15 Mar 2014 18:02:27 -0400 (EDT)
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Since the post, I took off the 30 meter add-on kit.  SWR is  exactly what 
it should be when the antenna is set up for just 12/17.  Any  suggestions?  
Test equipment here is an MFJ259 and  multimeter.
 
 


I recently purchased an almost new A-3WS and a brand new 30  meter  adapter 
kit form a ham in FL.

I've have two A-3WS 12/17  duobanders already in a stack and am  planning 
making this a three  high stack for 12/17.

Problem:

Assembled as per instructions,  double checked measurements,  orientation 
of 
the traps etc.  I  hauled the antenna up a tower to test  it....around 
15-20 
ft.   At this height, it might resonate a little low on  30 but be pretty  
much on the money for 12 and 17.

I get a very nice valley of SWR  for three bands, but not where they  
should 
be.
30 mtrs is  resonant at 9.8 mHz
17 mtrs is resonant at 19.67 mHz
12 mtrs is resonant  at 23.2 mHz

SWR at resonance for all three bands is around 1.2 and if  one did  not 
look 
at the freq on the MFJ, one would assume all is  good...nice normal  dips.  
What is really weird, is that two of  bands are too low and one is  way too 
high.

I realize the SWR  to be skewed slightly low at this height, but  these 
readings are  strange.

I have lots of experience putting together A-3 and a-3WS  antennas,  but 
have not used the 30 mtr kit.  

No overall  length of the driven element  with the 30 meter kit  added is  
given.  Anyone have that?  Other than that I am really   puzzled by this.  
Any 
suggestions?

Bill   K4XS


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