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Re: [TowerTalk] Yagi gain vs rotary dipole.

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Yagi gain vs rotary dipole.
From: Steve Hunt <steve@karinya.net>
Date: Tue, 25 Nov 2014 08:56:38 +0000
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Peter,

The method is not "wrong" - it's just "difficult"!

The results will *not* always be the same, because the two antennas were spatially separated and the incoming sky-wave signal had time-varying spatial amplitude and polarisation variations. So it's quite possible for the dipole to be "favoured" over the hexbeam at some particular point in time.

However, averaged across a large number of measurements you would expect these variations to "average out" and the real gain to become apparent. That's exactly what you see in the distribution:
http://www.karinya.net/g3txq/temp/hex_gain.png


Steve G3TXQ


On 25/11/2014 01:21, Peter Voelpel wrote:
Hi Steve,

You probably measured arriving signals with qsb so you just proved your
method being wrong, otherwise the result would be always the same.
You need to measure and compare the major lobes just outside the near field
to compare antennas.

73
Peter




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