Unless someone has access to NEC-4 or some even more restricted military
software the best you can do is guess when over anything but perfect ground.
Here is where actual work in the great outdoors has an advantage over doing
everything on a computer.
Building a working model for 6 or 2M has advantage of size as well as the
ease of a mobile station driving 360* a short distance away and recording
signal strength with the reflector in place with adjustable spacing as well
as removed. A paved driveway should simulate a poor ground rather well. A
chicken wire or similar mesh can simulate a very good ground.
Carl
KM1H
----- Original Message -----
From: "Dennis OConnor" <ad4hk2004@yahoo.com>
To: <towertalk@contesting.com>
Sent: Monday, September 10, 2007 1:22 PM
Subject: [TowerTalk] putting a reflector below a 75 meter inverted
>I have done some tests with a horizontal loop and putting a reflector
>underneath... Also, one year we had Field Day at my place and had an 80
>meter horizontal loop at 35 feet with a reflector loop about a foot off the
>ground... Opening and closing the reflector loop had an impact on how well
>the guys felt the loop was getting out... Using the loop on 40 meters there
>was significant improvement with the reflector loop circuit closed...
> We need to remember that the reflector will partially screen the ground
> directly underneath from 'some' of the current flow... It will not
> measureably change ground induced current loss in the near field beyond
> the immediate areas under the reflector...
> The bottom line in my mind is that a reflector will help, it will not
> hurt... The degree of improvement is subject to many variables..
>
> denny / k8do
>
>
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