Bill,
It almost sounds like you have a trap issue. I have one of the Cushcraft
D3W WARC dipoles for 12/17/30 which originally had a bad trap and was out
on all bands. Cushcraft admitted that they had a bad run of traps and
replaced all of them. This was several years ago.
Just a thought.
Good luck with the antenna.
Mike - KI8R
On Sat, Mar 15, 2014 at 6:02 PM, <Cqtestk4xs@aol.com> wrote:
> 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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>
>
>
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--
-----------------------------------------------
Michael Murphy - KI8R
mike@ki8r.com
twitter.com/ki8r
www.ki8r.com
614-371-8265 (cell)
4SQRP #388
QRPARCI #14941
NAQCC #6432
FLYING PIGS #3100
KX3 #3254
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