Content-Transfer-Encoding: 8bit
Message-ID: <3.0.1.16.20020430083716.2e1747a6@pb623250.kuleuven.be>
Date: Tue, 30 Apr 2002 08:37:16
To: rsgb_lf_group@blacksheep.org
From: "Rik Strobbe" <rik.strobbe@fys.kuleuven.ac.be>
Subject: Re: LF: It's up - No it's down or Antenna going on
In-reply-to: <6887944.1020097477486.JavaMail.computernetworks@gomailjtp0 5>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii; format=flowed
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Sender: <majordom@post.thorcom.com>

>My thoughts on the increased resistance are:
>
>a) the extension is above new ground outside the limits of the earth mat
which covers most of my property.
>
>b) the wood is rather dense and there are many smaller trees filling the
spaces, so it is very difficult to maintain the 2 metre separation
recommended by Laurie and others, especially when the wind blows!
>
>Any thoughts?

Hello John,

The increase in resistance you encountered is probably not a real
groundloss but rather a 'thee loss'. If the antenna wire goes high up with
little distance to the greenery RF tends to take the trees as 'back-route'
rather than the air.
But despite the increased loss resistance your signal seems to be 6dB (1
S-point up), and after all that is what counts.
I am also suffering from greenery losses, loss resistance varies from 100
Ohm in winter to 140 Ohm is summer. I did a lot of test to work arround
this problem and found that the most efficient way to increase the
radiation resistance was to put the loading coil (or at least a part of it)
high up. The antenna current didn't increase (in fact there was a slight
decrease), but the signal went up about 4dB. So always do some on-the-air
testing to see if there is an improveemnt, don't just rely on antenna current.

73, Rik  ON7YD