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[TowerTalk] Shadowing of antennas

To: <towertalk@contesting.com>
Subject: [TowerTalk] Shadowing of antennas
From: force12e@lightlink.com (force12e)
Date: Thu, 1 Feb 2001 14:11:33 -0500

Appreciate all of Guy's K2AV sage comments, as they are correct. The Force
12 140N element design is a product of more than 8 years elapsed time, 4
years of specific design time and 18 months of build it and validate time.
I put up the first two 340N's myself and they are still
running just as new. All Force 12 antennas are done following regimented
methodology,
time-consuming building and testing, outside consulting and various test
sites - that is
why it takes so long.

 I am impressed that Mr. Rauch has acquired an overhead of the C-39XRN, as
it has not
 been announced formally in our Brochure as a product and those delivered
were to people
 who were more of an insider than a customer. It, too, was a long
development project.
 The characteristics of the 140N element are well known to me, as I designed
it and have
 tested it in many environments and combinations. Placing the 40N driver
between the
 20-15-10 reflector zone and drivers modeled pretty well, as this element is
close to
 transparent. Nothing is truly transparent in the very near field, as it is
a hunk of
 metal, so there were adjustments made to compensate. The result is the
ability to have a
 wider boom for the 40 mtr spacing, while only extending the overall boom
3', which
 compares to very close spacing on the C-36XR with both 40 mtr elements out
the back of
 the antenna. The C-51XRN shares basically the same 240N spacing as on the
'39, except we
 were able to not extend the boom - nice, because it is big enough already!

 Someone want to know how we do it? Hard work and being honest during the
process.

 We have concurrent development projects going on all the time (most
prompted by customer
 requests) and release products only when they have been thoroughly tested.
If they do
 not meet our standards, they remain in the "files."

 One final comment - someone said something to the effect that an open
sleeve element
 combination acts like a trapped element - not hardly. If anyone has more
design and
 tower time than I do with open sleeves, let them stand up and be counted. I
also have
 the patent on the 3-band open sleeve, have built more than 70 different
designs using
 open sleeve driver cells and sleeved parasitic elements. The largest is the
C-49XR,
 which took close to 2 years after we had been shipping the C-31XR - and you
thought it
 was easy - just add another forward cell?!! They are nothing like a trapped
element.

 Always accepting suggestions for products and improvements. The SIGMA
verticals are one
 more example. They are a new era in verticals - again - took several years
to do it.

 73, Tom, N6BT
 Force 12, Inc.





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