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info on the K9AY loop
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Stunning
K9AY loop test
By John Bryant
IRCA's AM DX NewsFlash, March 30, 2000
This Grayland DXpedition, on the first weekend in March 2000,
consisted of Don Nelson, Guy Atkins, Walt Salmaniw and Bill Smith,
W5USM, from Dallas and John Bryant.
Various antennas were in use, including four beverages pointed at
various directions and two K9AYs.
The medium wave conditions were about what I remember from near
the peak of the last sunspot cycle. Signals were noted on many channels,
but most at only threshold level. Most of those that became quite
good tended to remain so for only short periods of time before diving
back into the mud.
I spent the morning of the 13th entirely on comparing our
best 1000' beverage (bore-sighted on Japan and the China coast)
with Don Nelson's Wellbrook Communications K9AY loop.
The results were semi- stunning.
On a couple of dozen MW signals from Japan and the Koreas, the beverage
never out-paced the loop. About 80 percent of the time, they
were indistinguishable. The other 20 percent of the time, the Wellbrook
K9AY was clearly superior, usually because it did a better job of
rejecting relatively high angle splatter from nearly co-channel
nearby American stations.
The performance of the K9AY was so impressive that I did not even
bother putting up beverages for the second weekend.
The second weekend, March 18,19,20, I DXed solo on Saturday
and Monday mornings but was joined for Saturday night/Sunday morning
by MWDX legend Bruce Portzer from Seattle.
We were using my own special Wellbrook K9AY model which offers 8
separate directional possibilities (using four loops) rather than
the four directions available with the standard two-loop K9AY.
Bruce was the chief operator of the antenna Saturday night and pretty
well fell in love with it, too. He, too, appreciates the choices
available with a directional antenna at every 45 degrees. We both
came away from the weekend feeling the additional hassle/expense
of a four loop K9AY was a worthwhile investment.
I should note that the 10 dB amplifier (switchable) in the Welbrook
version of the K9AY made substantial improvements in the
S/N ratio on weak international MW signals as well as those on long
wave. This amplification might be the root of the differences in
experience with the Wellbrook version of the K9AY and the experience
of some homebrewers. |
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