[Antennas] Antennas + reccomedations

Thu, 21 Feb 2002 12:36:56 +0200

Hi Clinton

The log-periodic and Hexbeam are very different antennas.  I presume the
KMA log-periodic is large and probably has gain equal to a 3 element yagi on
the same frequency.   The Hexbeam is essentially a compact, lightweight
beam which also works well as a portable beam on field days and expeditions.

The Hexbeam configuration is a 2 element beam that resembles an inverted
umbrella with the convex side pointing to the ground and the concave side up
to the sky.  The antenna is available in several models covering
combinations of various bands.  Each band consists of a separate reflector
and driven element.  This all sounds very complex, but it is just like an
umbrella with wires strung on the inside.

The antenna folds up and is transported in a canvas bag.  There is also an
extra lighweight model available for field day operation, but even the
normal models are light enough to carry around.

The compact size of the array is achieved by squashing each director into a
W and each driven element into an opposing W.  These Ws lie horizontal in a
mirror image to each other.

A normal multiband yagi would have traps in the elements to cover the
different bands, but the spacing is only optimal for one of the bands.  The
Hexbeam has a separate 2 element beam for each band with near optimal
spacing for each band.  The good spacing is achieved by placing the high
band in the narrow part of the umbrella and the low band at the wide part of
the umbrella.

The Hexbeam is used on many rare expeditions and a recent famous operation
was the expedition of December 2000 when Traffie donated their top model to
Chuck Brady N4BQW / 3Y0C to use on Bouvet Island.  The terrible conditions
on the island is testimony to the ruggedness of the antenna.

Visit www.hexbeam.com for all the specificatoins and www.qsl.net/zr1dq for
operating conditions and photographs of the beam on Bouvet Island.  The
Bouvet Island beam lives proudly here in Cape Town.

The Hexbeam is very compact and the log-periodic may have more gain.  Your
installation and operating requirements will probably determine your choice.

Good luck.

Regards
Deon ZR1DQ
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----- Original Message -----
From: CMBailey <[email protected]>
To: <[email protected]>
Sent: Tuesday, February 19, 2002 4:44 PM
Subject: [Antennas] Antennas + reccomedations

Hi;
 The current discussion on GEO-clock and using it for aiming ones beam is
interesting, and i surely hate to change directions, but, i am in the
process of erecting a tower, and am looking at antennas to grace the top of
it.
 I have been looking at the Log Periodics from KMA and the Hex-Beam from
Traffie Tech, and was just wondering if there is anyone on the list that has
any experience with either of these antennas and would share their thoughts.
 Also, if there is anyone in the Southern part of the state of Georgia that
has a Hex-Beam????
 Thanks for reading.
 73
 Clinton
 NT4E

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