Date: Sun, 18 Jun 2017 21:45:31 -0700
From: Grant Saviers <grants2@pacbell.net>
To: jbwolf@comcast.net, towertalk@contesting.com
Subject: Re: [TowerTalk] 40 Meter Yagi
There are three W6NL Moxon designs available if you look on the web,
particularly the K3LR Dayton Antenna Forum presentations. I've built
two of the original 120mph "scratch" designs. Later came XM-240
modified aluminum for K3LR and then a strengthened version for him.
AFAIK, they are still in use in a stack at K3LR. Mine is still up at
91' and used in conteests but a full size 3L 40m beast is 50' higher and
is my go to DX antenna. I wouldn't call any of the W6NL Moxon designs
"compact 40's" due to the footprint of the antenna on the ground with
the Moxon tips and the turning radius. google "w6nl moxon"
Generally, it seems coil loading has supplanted linear loading.
JKantennas has both a compact coil loaded and compact coil plus Moxon
40m in their catalog. The mechanical engineering is 1st class.
Grant KZ1W
## https://jkantennas.com/jk402t.html This is the 40m, 2 el moxon that JK
makes.
https://jkantennas.com/antennas.html They make 6 x 40M monoband yagis, and
1 x 40M rotary dipole. Plus 2 x combo 30-40m yagis.
http://optibeam.net/index.php?article_id=104&clang=1 This is the 40m, 2 el
moxon
that optibeam makes. 19.7 ft turning radius.
http://optibeam.net/index.php?article_id=22&clang=1 16 x ants with 40M.
Plus 6 x more that are 40m only.
## a strengthened XM-240 + 4 x hb coils to replace the oem CC coils would be
another option.
You cant cook HB 80+ 40m coils...nor the solid .25 al coils that JK ants
uses.
## You could also HB any of these 40M designs. The tubing is cheap at DXE and
else where, but
that takes more time, requires effort, etc, but the end results are good. One
of my drill presses
has been modified to handle large sheets of Al..that I require to build HB
amplifier chassis with, including
19 + 24 inch wide front + rear panels. IE: loads of depth, like 15 inches.
The 2nd drill press is unique. The 6 x 6 table can be flipped 180 degs,
which has a V running the entire length
of the table. The V is made for any diam tubing. Easy to clamp down
tubing + pipe in a V trough.
In F12s book, array of light, he shows a pix of a hb jig, that is essentially
a V, consisting of 90 deg angle AL or
angle steel, with trough facing up. Same idea, tubing sits in the trough,
easily clamped down. Then the holes
are centered correctly. Bit more of a trick when trying to drill say .25
holes into 3 inch OD tubing..since the typ
,25 bit is not very long. Like for the case where you want to put a .25-20 SS
bolt right through the 3 inch OD tube.
I use the wifes combo metric-Sae cloth measuring tape, and measure the exact
circumference. 3 inch OD tube has a 239.268 mm
circumference. 9.42 inchs. Half of that is of course 119. 634 mm or 4.71
inches.
Jim VE7RF
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