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[TowerTalk] delta loop beams - how to feed.

To: <towertalk@contesting.com>
Subject: [TowerTalk] delta loop beams - how to feed.
From: ei8ic@eircom.net (Tim Makins, EI8IC)
Date: Tue, 18 Sep 2001 10:00:34 +0100
Hi Henry and others - I'd be interested to know where and how this antenna
was fed. According to the books I've seen, an upside-down delta loop needs
to be fed in one of the top corners for long distance working, but I can't
see how you can do this without the feedline interfering with the element.
When you say 'Each band was fed with separate feedlines through gamma matchs
affixed to the boom', that implies that it was fed where the two aluminium
tubes met the boom, which my book says has a radiation angle of 47deg.

73s Tim EI8IC

----- Original Message -----
From: <K4tmc@aol.com>
> The antenna you are inquiring about was the model DL-TRI by Delta Loop
> Antenna, Inc. of Weston, VT (previously in New Milford, CT).  The company
is
> no longer in business.  The owner, Robert Hobert, KA1UJ is, I think, a SK.
> The array is very strong, using none of the standard U-bolt type clamps.
> Element-to-boom and boom-to-mast joints are all done with heavy-duty solid
> machined aluminum parts, not castings, and stainless steel hardware.  Two
of
> the 3 sides were made of aluminum tubing that rose from the boom at an
angle
> with a copper wire stretched across the top for the 3rd side of the delta
> loop.
>
> I purchased what may be one of the last DL-TRI's back in April 1993, when
he
> was not actively building any arrays with 10 Meter capability due to the
low
> sunspot activity at that time.  The array included 2 elements on 20 and 15
> meters plus 3 elements on 10 meters and weighed 81 lbs when fully
assembled
> on a 13.5 ft boom.  Each band was fed with separate feedlines through
gamma
> matchs affixed to the boom.  There was a review of the DL-TRI in CQ in
June
> 1988 by Lew McCoy, W1ICP.



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