[TowerTalk] FW: Cushcraft A-3 WS with 30 meter kit-PROBLEM (update)
maflukey at gmail.com
Sat Mar 15 19:07:50 EDT 2014
I would check the 17m traps that come with the add-on kit before anything
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of
Cqtestk4xs at aol.com
Sent: Saturday, March 15, 2014 5:02 PM
To: TOWERTALK at contesting.com
Subject: [TowerTalk] Cushcraft A-3 WS with 30 meter kit-PROBLEM (update)
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.
Assembled as per instructions, double checked measurements, orientation of
the traps etc. I hauled the antenna up a tower to test it....around
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
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
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.
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