[TowerTalk] K9AY performance expectations/help

[K4SAV]

Your problem is more than likely the result of interaction with the 
transmit antenna (but you suspected that already).  As a quick test, 
listen to a European station on 80 with the K9AY pointed SW.  Then at 
the station end of the feedline to the 80 meter loop, either open or 
short the coax.  If you hear any change of the signal on the K9AY, you 
have the answer.  You may be able to solve the problem by changing the 
length of the feedline to the loop.  Another option may be to add a 
relay to either short or open (whichever works) the end of the coax 
during receive.  You will need to check for the same thing on the other 
bands.

Jerry, K4SAV

Scott McClements wrote:
> 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
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