----- Original Message -----
From: "Doug Renwick" <ve5ra@sasktel.net>
The
> real result, as you state, is the A-B test using reliable methods.
I have done some A-B testing, informal but perhaps interesting anyway.
For the past three years I have tried to get a better 160m contest
antenna.
Many postings have raved over an inverted L. My A antenna during the
first year contest was an inverted L with about 80' vertical and 50 some
feet horizontal and about a dozen radials. The second year A antenna
improved(?) the inverted L to about 100' vertical and some 30 feet
horizontal and about 15 radials raised about 15' at the base and
insulated. My third year A improved to a slightly sloping vertical
with
no horizontal portion and about 50 radials. These radials were
connected to a DX Engineering radial plate and the radials varied from
50' to 200 feet in length. All were fed with about 50' of RG213.
The B antenna for all three years was an 80m double extended zepp (320')
fed with ladder line. The center of the dipole is about 105' and each
end is about 60' high. The center is about 4' from the trunk of a
Douglas fir. Each of the verticals were pulled up to the same fir
tree but not that close to the dez.
Both the A and the B antennas were feed lines were connected to
identical TENTEC model 238a tuners. Using a coax switch I could
switch instantaneously from A to B to A and so on.
RESULTS:
In terms of contest results, each succeeding year brought somewhat
higher scores but that may have been due not to the antenna
but band condx. And for the third year a friend's xyl ham probably
brought in quite a few more exchanges with her pleasant voice!
In terms of A-B comparison which I did many of. Never, not once, did
the first year tree supported vertical L antenna even come close
to equaling the dez. The second year was a little better but still not
once did the higher vertical L equal the dez. The third year was
much better with several (3 or 4) contacts were better on the vertical
and quite a few were a toss up.
All of these A-B comparisons were receiving strength only. Sometimes
the first year vertical signals were quite a bit weaker than
the dez, however I doubt that it would have prevented an exchange. Some
might say that the antennas worked well. From my area
in Puget Sound I managed about 150 qso's in about 50 states. Never once
did I even hear a European or other dx station. So much
for the low angle benefit of the vertical??
It was fun though to listen to occasional micro pileups with the third
year antenna, the KW, and the female 160m contester at work!
(hope this of interest to someone)?
l7puc
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