From W6NL: The history of this antenna begins with my 2003 antenna with
27-foot boom, designed for our 125 mi/h (200 km/h) winds. See
https://www.kkn.net/dayton2004/dayton-2004-antenna-forum.html This
antenna is still in use here. Copies were built by K5MR, K6KR, KZ1W and
others. The K5MR antenna is now at N4BAA.
In 2007, K3LR asked me to modify the design for less wind load than we
have here, for convenience to be built with available parts of the
Cushcraft XM240. See http://www.kkn.net/dayton2007/w6nl_ant.pdf and
http://www.k3lr.com/engineering/ The first try
www.k3lr.com/engineering/moxon/W6NL_Moxon104.pdf was not quite strong
enough for the winds there, so a modified design was made in 2010 as
www.k3lr.com/engineering/moxon/W6NL_Mox_100.pdf In 2012, W2SC asked me
to provide an updated design to use at 8P5A, see
www.k3lr.com/engineering/moxon/W6NL_Mox_Tube_100.pdf For a discussion of
modeling this type of antenna, see
www.k3lr.com/engineering/moxon/W6NLMoxonModeling.pdf
These have been built by W1UJ and K1KP in a project of the Yankee
Clipper Contest Club, for their own use and for W2SC/8P5A. See
https://w1uj.net/Moxon/ Here you will find many files describing their
work to build these antennas. See particularly K1KP's Dayton talk
https://www.kkn.net/dayton2012/DaytonAntennaPaper05102012.pdf and
https://www.yccc.org/Scuttlebutt/2011/butt2011_10.pdf Also see
https://w1uj.net/Moxon/K1KP/readme.html
In 2014 I was asked by WE9V to update the design to account for some
minor errors he found in the wind calculations. Also, he wanted to make
his antenna from 6-foot (2-meter) lengths of tubing. The antenna was
finished in 2015, see https://www.we9v.com/antennas.htm The element
dimensions for this antenna are in WE9V Moxon 100 mi.pdf and Visio-Moxon
Cushcraft XM240 40M.pdf The dimensions from WE9V are here, from an email
from me to him near the end of his project:
"So in summary, an antenna making good use of XM-240, especially the
expensive bigger sections, has 99 mi/h survival and should have the same
electrical performance as the other W6NL-Moxons. The elements, all with
0.058" wall, are as follows for the reflector, which is the more
stressed element:
1-1/2"x72" EH and EA used as reinforcement, add new 1-1/4"x24" inside
1-3/8"x72" 42" exposed, with reinforcement inner 24"
1-1/4"x48" 45" exposed, EB
1-1/8"x48" 44" exposed, EC
1"x16" 13" exposed, half ED
7/8"x18" 14" exposed, new part
3/4"x6" Reinforced, new, to mount cross element
1/2"x48" 39" exposed , EF (could be more or less)
3/8"x36" 13.25" exposed, half EJ, for proper tip length
For the driven element:
1-1/2"x72" EH and EA used as reinforcement, add new 1-1/4"x18" inside
1-3/8"x72" 42" exposed, with reinforcement inner 15"
1-1/4"x48" 45" exposed, EB
1-1/8"x48" 44" exposed, EC
1"x16" 2" exposed, half ED
7/8"x18" 2" exposed, new part
3/4"x6" Reinforced, new, to mount cross element
1/2"x48" 39" exposed , EF (could be more or less)
3/8"x36" 32.5" exposed, EG, for proper tip length
I hope this is what you were looking for. My grandkids always tell me "TMI."
There are also commercial versions of my design, such as W3JK's JK402T
https://jkantennas.com/jk402t.html, see also
https://ac0c.com/main/page_acc_towersantennas_40m_stack.html The JK402T
has several clever mechanical features, such as the mounting bracket for
the cross elements. But it is expensive, so many hams prefer to build
from scratch. DX Engineering has been rumored to be considering offering
a kit based on my design, but nothing concrete at the moment.
73 de Dave, W6NL/HC8L/P40Q
On 5/20/23 1:33 PM, marsh@ka5m.net wrote:
The attachment didn't work, so here's the link:
http://www.k3lr.com/engineering/moxon/W6NL_Moxon104.pdf
Hope this helps.
Marsh KA5M
-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of BRUCE FORD via
TowerTalk
Sent: Saturday, May 20, 2023 2:54 PM
To: TowerTalk@contesting.com
Subject: [TowerTalk] Xm240 to moon
I know I am late (always) to this but downsizing and replacing the 160 ft rotating
tower with a nice 3el 40 with a 70ft Tristao and a XM240. The band width is not so
great and have been reading about this upgrade. I can find no actual pictures of the
Moxon element fully constructed so I have to assume looking at tubing lengths each
element is about 18ft in total or 9 a side from the boom. Sorry so stupid…just
getting old I guess.If anyone has picture of element end constructed and mounted that
would be great.
Thanks for any help
Bruce K9RO
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