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Re: Topband: How much ground independence?

To: "chetmoore" <chetmoore@cox.net>
Subject: Re: Topband: How much ground independence?
From: "Bruce" <k1fz@myfairpoint.net>
Date: Mon, 9 Dec 2013 13:42:47 -0500
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Hi Chet,

Think the closer radials were coupling transmit tower signals to the loop.
Detuning the transmit antenna may also have fixed the problem.

I am trying to find out how much the loops hear from the transmit radials. You may have answered that question.

Thank you,
73
Bruce-K1FZ





----- Original Message ----- From: "chetmoore" <chetmoore@cox.net>
To: "'Bruce'" <k1fz@myfairpoint.net>; <topband@contesting.com>
Sent: Monday, December 09, 2013 12:43 PM
Subject: Re: Topband: How much ground independence?


Hi Bruce,



I can't speak to a flag but I had a W2UP rotatable loop that I turned with a small TV rotor and one of your transformers. It worked great for about year until
I ran 4 or 5 radials out to within about 10 feet of it. Bottom of the loop
was about 8 feet off the ground. It lost all Directivity  and once taken
down at the end of the 160 season,  I never  Put it back up.

 There was the possibility to get the bottom wire up 15 feet
Higher were I to put it back up but really did not expect that to help and never put it Back up. It was quieter than the shunt fed tower and seemed to pull the
weaker sigs Out of the noise when I switched between the 2.

Sigs from the west coast were particularly weaker here this year than I
remember them Being last year. In the test this weekend, I missed working ve7oo. He had a
lot of qsb

On him at this qth and I could not hear which stations he was coming back
to. I wonder If the loop would have pulled him in. I too wonder if adding 10 -20 feet in height Above the radial field would get the directivity back. That could be a project for A warmer and dryer day than we have today. Some consideration has been
given to digging

Up the radials noted above or  shortening them by 20 - 30 feet. If I had
reason to believe It would help, I could get it up another 20 feet and shorten the radials by
that amount.

I did not detune the loop on xmit.  As for good front to back, The loop
could hear Sigs that were not audible on the shunt fed tower Those sigs of which I speak, were Not moving the s meter but it was the difference between knowing they were there and Being able to copy well enough to call the station after they called CQ.

73
Chet N4FX



-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Bruce
Sent: Monday, December 09, 2013 11:51 AM
To: topband@contesting.com
Subject: Topband: How much ground independence?



Has anyone installed a Flag antenna over a radial field?



What was the flag height above ground?



Did it hear well and have a good front to back?



If poor performance, did de-tuning the transmit antenna make a large
difference ?



If the flag was moved to a non-radial field location, what was the
difference?



Thank you in advance,



73

Bruce-K1FZ

<http://www.qsl.net/k1fz/beveragenotes.html>
www.qsl.net/k1fz/beveragenotes.html

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