[TowerTalk] K9AY performance expectations/help

[john at kk9a.com]

I tried a K9AY loop and mine worked pretty well on 160m.  On 80m my TX 
antenna was a 90+ ft long rotatable homebrew dipole at 160ft high about 350 
ft away and I don't recall ever hearing a station on the K9AY loop that I 
could not hear on my transmit antenna.  The K9AY loop is ground dependant 
and your TX antenna my be effecting it somewhat, but I'm not sure if you'll 
ever see dramatic results on 80m.

73,
John KK9A


To: towertalk reflector <towertalk at contesting.com>
Subject: [TowerTalk] K9AY performance expectations/help
From: Scott McClements
Date: Fri, 28 Aug 2009 22:09:01 -0400

Hey All,

I put up an Array Solutions K9AY RX Antenna this summer for 80m/160m.
The antenna is placed over rich marshland (freshwater). In fact we've
had so much rain that its nearly over a pond.  I have one 8' copper
ground wire hooked to it, no radials. I have been doing tests with a
local AM broadcast band station (1.390Mhz).  When I check the
directivity with that station, everything seems good. I am seeing at
least ~24dB of attenuation when I select the two directions away from
the broadcast station. I haven't done any tests on 160 meters with it
yet. I have a full sized 80 meter loop (square) - vertically oriented
and vertically polarized.  Its about  80 feet from the K9AY.  The K9AY
is on the north east side of the TX antenna (EU side).  My full sized
transmitting loop is oriented NW/SE, thereby it produces slightly more
gain in the NE/SW directions (towards EU).

On 80 meters, the performance just doesn't seem right. I can't seem to
tune any type of directivity (rear null) by varying the termination
resistance (using DX signals).  In no situation has the K9AY allowed
me to copy a signal that I could not already easily hear on my TX
loop. When I vary the termination resistance, in fact I don't detect
any change in the F/B at all.  That was true for the broadcast band
test too.

Any ideas? Is it the ground? Maybe the termination resistors aren't
being switched right ? (I do get a 60 over pop on the s meter when I
switch the termination). Perhaps my fullsized 80 meter loop is pretty
good already and I expecting too much?

I did two YouTube videos to try to capture what I am seeing.

Broadcast band test:

http://www.youtube.com/watch?v=W8gvnb9JI80

W2 to EU on 80m, video is a little long, listen around  1 minute 24
second mark. OK3BJJ calls and I start in SE direction and swap around
to the SW direction. There is no detectable change in that sweep.

http://www.youtube.com/watch?v=LmgDMNK2axc

I have also used the time signal on 3.810Mhz (SW direction from here).
In most cases the time signal is not audible on the K9AY and is Q5 on
my TX loop.

-Scott, WU2X