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Date: Tue, 16 Mar 2010 13:59:29 +0000
Message-ID: <9afca2641003160659r4a659ae5re0a7a46ca1ba9f43@mail.gmail.com>
From: Roger Lapthorn <rogerlapthorn@gmail.com>
To: rsgb_lf_group@blacksheep.org
DomainKey-Status: good (testing) 
Subject: LF: 8.97kHz antennas
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Getting a Marconi vertical up in the sky is no mean task when 100m long and
carrying a decent antenna current so I was wondering whether there is any
merit in using grounded electrode pairs (as used for through-the-ground
"earth mode" conduction tests) possibly fed with elevated feed wires as an
alternative?

Not being much of a theory man I've little idea how this would perform and
what amount of the 8.97kHz energy injected into the loop thus formed would
actually be radiated. Clearly stringing out a 200m long grounded electrode
pair "antenna" in a big field would be considerably easier than raising a
kite mounted vertical. This arrangement on a much larger scalle was used at
76Hz for Project Sanguine (to radiate a signal to submarines, deeply
submerged) and papers I've read on "earth mode" caution that for military
applications the through-ground path may not be secure because of the amount
of energy radiated. I also recall that G0AKN used this arrangement with some
success on 73kHz.

Anyone know the answer?

73s
Roger G3XBM
-- 

http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/G3XBM
G3XBM    GQRP 1678      ISWL G11088

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Getting a Marconi vertical up in the sky is no mean task when 100m long an=
d carrying a decent antenna current so I was wondering whether there is an=
y merit in using grounded electrode pairs (as used for through-the-ground=
 &quot;earth mode&quot; conduction tests) possibly fed with elevated feed=
 wires as an alternative? <br>
<br>Not being much of a theory man I&#39;ve little idea how this would per=
form and what amount of the 8.97kHz energy injected into the loop thus for=
med would actually be radiated. Clearly stringing out a 200m long grounded=
 electrode pair &quot;antenna&quot; in a big field would be considerably=
 easier than raising a kite mounted vertical. This arrangement on a much=
 larger scalle was used at 76Hz for Project Sanguine (to radiate a signal=
 to submarines, deeply submerged) and papers I&#39;ve read on &quot;earth=
 mode&quot; caution that for military applications the through-ground path=
 may not be secure because of the amount of energy radiated. I also recall=
 that G0AKN used this arrangement with some success on 73kHz.<br>
<br>Anyone know the answer?<br clear=3D"all"><br>73s<br>Roger G3XBM<br>--=
 <br><br><a href=3D"http://g3xbm-qrp.blogspot.com/">http://g3xbm-qrp.blogs=
pot.com/</a><br><a href=3D"http://www.g3xbm.co.uk">http://www.g3xbm.co.uk<=
/a><br>
<a href=3D"http://www.youtube.com/user/G3XBM">http://www.youtube.com/user/=
G3XBM</a><br>G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088<br>

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