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Message-ID: <006e01cae6e3$2d46f4b0$4001a8c0@lark>
From: "Alan Melia" <alan.melia@btinternet.com>
To: <rsgb_lf_group@blacksheep.org>
References: <003201cae3db$b7ffad50$0301a8c0@your91hoehfy9g>,<MFEJIKCLCMPDFHOKMANAIEIFOHAA.paulc@snet.net> <BF4A524700075746A6467658DFC7102C19A2156E82@ICTS-S-EXC2-CA.luna.kuleuven.be>
Date: Wed, 28 Apr 2010 15:57:49 +0100
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Subject: LF: Re: RE: W1VLF 8.97 KHz UPDATE  Trees,  Questions, Ground
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Rik ....Reduce the effect of the trees?? How about reducing the voltage on
the antenna?? this is effectively what the loopers did on 136 and then hung
their loops in the trees. Will it work at 9kHz ?? Probably have to try it to
see......

Alan
G3NYK

----- Original Message ----- 
From: "Rik Strobbe" <Rik.Strobbe@fys.kuleuven.be>
To: <rsgb_lf_group@blacksheep.org>
Sent: Wednesday, April 28, 2010 3:31 PM
Subject: LF: RE: W1VLF 8.97 KHz UPDATE Trees, Questions, Ground


Hi Paul,

Looking here  http://rescueelectronics.com/9-Kilohertz.html near the bottom
of the page one can see that the tower is backed up by forest.
I wondered how much, if any,  effect on antenna current running a long
radial out in the forest would have?

It might increase the loss resistance.

It is a kind of trade-off: one the one hand more "area coverage" will reduce
the loss resistance (cfr. Laurie's footprint theorie) on the other hand
coming close to or even going over any greenry will cause an increase of the
loss resistance.

If it isn't too much trouble: just try and measure

A) Am I just giving the trees a better return path or  ground connection
(the radial)  to the coil???
And the power is being eaten up by the trees???
OR
B)  Is there a chance this power is actually being radiated, and therefore I
should pursuit accumulating these grounds, and their current and return it
to the coil??

The only way to avoid that power is "eaten" by the trees is staying way from
them (or remove them).

Apart from than there is little you can do. Or maybe trow wires over the
tree and connect these wires to the ground system (not very practial I'm
afraid).

But, with or without trees:, the better the ground system (rod's) the more
efficient the antenna will be.

What is a tree at 9 KHz???
A very lossy capacitor ?

73, Rik  ON7YD - OR7T