[TowerTalk] Full Size Moxon is Up

[Tim Duffy K3LR]

HI Ron!

Yes, I understand the two camps!

DX propagation conditions were very challenging on 40 meters for the last 4
DX contests. The K3LR 40 meter operators did lots of comparisons during the
past season between the new W6NL-Moxon stack on the second station at 185'
over 120' (these were brand new modified XM-240s) and our 40 meter main
station which is a stack of full size, four element OWA antennas at 190'
over 118' that have been up for 12 years. Both 40 meter antenna systems have
on tower switching systems that allow the operator to select feeding in
phase, out of phase or just a single antenna and all 4 antennas are
independently rotatable. The two towers for these arrays are 1100 feet
apart. 

The performance (forward gain, pattern and VSWR bandwidth) of the 4 element
OWA stacked antennas is better (they have more than twice the boom length
and full size elements), but the W6NL/Moxon design worked much better
(improved front-to-back and greater VSWR bandwidth) than the old CushCraft
402CD that we used to use for the 2nd station at 140 feet. 

73!
Tim K3LR  
http://www.k3lr.com
K3LR DX Cluster telnet://dx.k3lr.com
 

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of Ron Chambers
Sent: Monday, March 17, 2008 4:21 PM
To: k3lr at k3lr.com
Cc: David Gilbert; TOWERTALK at contesting.com
Subject: Re: [TowerTalk] Full Size Moxon is Up

GREAT! (ps, this Moxon is the built from scratch unit, not a modified shorty
40)

We also have our main 40m tower (140ft) with two 402CD's on it and have been
considering stacking Moxons. But there seems to be two camps out there on
"does it work" or "not". Yours obviously does. Were they modifed 402's? What
heights, etc?

Ron
N5QQ





On 3/17/08, Tim Duffy K3LR <k3lr at k3lr.com> wrote:
>
> Congrats Ron! You will really like this antenna!
>
> We used a stack of these antennas during the past 4 DX contests for our 40
> meter second station and they worked great!
>
> For those wanting the conversion document (CushCraft XM-240 to W6NL -
> Moxon), it is available on http://www.k3lr.com Click on STATION
> ENGINEERING
> - then 1st topic.
>
> 73!
> Tim K3LR
>
> -----Original Message-----
> From: towertalk-bounces at contesting.com
> [mailto:towertalk-bounces at contesting.com] On Behalf Of Ron Chambers
> Sent: Monday, March 17, 2008 3:38 PM
> To: David Gilbert
> Cc: TOWERTALK at contesting.com
> Subject: Re: [TowerTalk] Full Size Moxon is Up
>
> Full-size Moxon is finally up and installed on the KC5FU Contest Station
> Multiplier Tower.
>
> I think some of you had questions after it went up, but I don't recall
> who?
>
> Ron/N5QQ
>
>
>
>
> On 10/18/07, Ron Chambers <rwchambers at gmail.com> wrote:
> >
> > This weekend or maybe next, we (N5QQ/W5WW) should have Dave Leeson's 2
> > elem 40m MOXON up and running. Will offer our comments afterwards. K5MR
> > got his up a few months back and seems to be pleased, well, until the
> > lightning storm fried his rotor!
> >
> > More later...
> >
> > Ron
> > N5QQ
> >
> >
> >  On 10/17/07, David Gilbert <xdavid at cis-broadband.com> wrote:
> > >
> > >
> > >
> > > Force 12's own website says their more recent coil-loaded Delta 240 is
> > > intended to replace the older linear loaded EF-240S, their explanation
> > > being:
> > >
> > > "The most difficult aspect of the antenna was tuning the elements to
> the
> > > proper frequencies for maximum performance.  This is because the
> linear
> > > loading had variances during assembly."    see
> > > http://force12inc.com/F12-Delta-240-140-Info-1.htm
> > >
> > > Several reviews on eHam.net additionally report problems with the
> stiff
> > > Alum-O-Weld loading wires/**/ breaking, so I suspect that also had
> some
> > > impact on F12's decision to create the Delta 240.  In theory, the
> Delta
> > > 240 is similar to the OptiBeam OB2-40 (the choice I made as well), but
> > > the Delta 240 elements are a bit shorter and I'm sure the OptiBeam is
> > > more ruggedly built.
> > >
> > > Dave   AB7E
> > >
> > >
> > >
> > > john at kk9a.com wrote:
> > > > I'm not sure that linear loading is as efficient as some
> manufactures
> > > claim
> > > > and some models require a lot of adjusting of the linear loading
> wires
> > > for
> > > > the antenna to perform properly.  I personally prefer a loading coil
> > > and
> > > > when looking for a small 2el beam for P40A, I choose the OptiBeam
> > > OB2-40.
> > > > The coils are massive, the antenna is well constructed and easy to
> put
> > >
> > > > together.   My second choice (actually first choice if budget ruled
> > > out the
> > > > OptiBeam) would be the Cushcraft XM240.
> > > >
> > > > John KK9A
> > > >
> > > >
> > > >
> > > _______________________________________________
> > >
> > >
> > >
> > > _______________________________________________
> > > TowerTalk mailing list
> > > TowerTalk at contesting.com
> > > http://lists.contesting.com/mailman/listinfo/towertalk
> > >
> >
> >
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