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Topband: Eu/SA heard this A.M. in VK6/UZI antenna

To: <topband@contesting.com>
Subject: Topband: Eu/SA heard this A.M. in VK6/UZI antenna
From: sire at iinet.net.au (Steve Ireland)
Date: Mon Jun 9 07:12:00 2003
G'day all

I came on the band at 2225Z and started to call 'CQ DX' on 1833, beaming
south and looking for PY2FUS.  At about 2238Z, I heard a weak S1 signal and
 switching the delta loop array to the north, discovered it was LY3UM  who
was 579 - the F/B on the antenna really works!  When I listened for a few
minutes, I realised LY3UM could hear PY2FUS calling CQ and was calling him
(although he was having trouble with the latter's callsign).

After LY3UM, I then heard G3FPQ (at RST 579) calling PY2FUS and then
working him.  To my surprise, I started to hear traces of PY2FUS's signals
at 2246Z, but only the odd character, at S1/S2.  By the end of his QSO with
G3FPQ, Ron's signals had disappeared.

I listened on 1833 until 2257Z, when I looked around the band and worked
G3FPQ on 1831, who had dropped to S5.  He was S3 and hard to read on the
omni configuration of the antenna.

When I heard PY2FUS, I was actually beaming north - the quietest direction
of the antenna.  Since putting up the beam, I have discovered most of the
noise/crud I have comes from the south - which was very noisy this morning.
 Beaming south my noise level was S5/6, whereas beaming north it was S0/S1.

By the way, the delta loop array definitely shows gain - G3FPQ was about
two 'S' units better with the north beam configuration than with the single
omni-directional loop configuration.  I could not hear PY2FUS at all on the
single loop configuration. 

For those who are interested in my 2-element delta loop antenna, it is
derived from the article by Tony Preedy A45ZZ (G3LNP) in November 1993
Radio Communication (the RSGB journal).  The loops used here are three
quarters (or thereabouts) of full size and linear/capactively loaded in the
base - the sides of the loops are around a quarter wave in length.  The
array could also be considered as two pairs of quarter wave verticals, each
pair slightly more than an eighth wave apart, and each vertical in the pair
spaced about a quarter wave at the base.  

I am thinking of calling it the 'UZI' - being a very large amount of
firepower in a very small footprint.  It maybe written up at some stage (no
promises when, as with two small kids and a working wife, time is VERY
short and I still need to optimise the antenna...).

Vy 73

Steve, VK6VZ



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