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Date: Thu, 17 Jun 2010 21:41:26 +0100
Message-ID: <AANLkTin5sumGSuy3XGXNK1jxKthgldBJLcCQsKj54vzp@mail.gmail.com>
From: Roger Lapthorn <rogerlapthorn@gmail.com>
To: rsgb_lf_group@blacksheep.org
DomainKey-Status: good (testing) 
Subject: LF: Earth electrode loop and 500kHz ERP
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For a hand-drawn sketch "system diagram" showing the ground points, wire
routing of the earth electrode loop antenna, please visit my blog at
http://g3xbm-qrp.blogspot.com/

These notes are to clarify the diagram...

   - I'm using this earth electrode "antenna" to TX with on 500kHz and on
   sub-9kHz. It has not been tried on 136kHz (yet).
   - The wire runs down the garden fence (1.5m above ground) from the far
   electrode (1.5m in the soil) then coming up along the study roof to the
   upstairs bedroom where it connects to the inner of a coax cable. The outer
   of the coax is grounded to the copper pipes of the central heating system at
   this point.
   - The copper pipes within the house eventually join with the water pipes
   in the street (to the right in the diagram).
   - From the feed point, a 10m long coax goes through the house to the
   front bedroom where I have my 5W out transverter for 500kHz and my 4W
   sub-9kHz TX beacon.
   - No attempt at matching this has been made at all on 500kHz - I just
   connected to the wire and radiator at the end of the coax. On sub-9kHz I use
   a step-up transformer to match to around 40-60 ohms resistive (measured).
   - The local rock (below about 2m of limy soil) is chalky "clunch".
   - On 500kHz I've measured 34V with a diode probe at the feed point at the
   end of the coax in the rear bedroom (LHS of the house in the diagram) where
   it is grounded to the radiator and the wire starts its journey down the
   garden.

Questions:

   1. Now, how big is the loop thus formed?
   2. How much of this is within the ground?
   3. What is the 500kHz ERP likely to be?

Best report this evening so far is -26dB S/N from G0KTN at 210kms.

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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For a hand-drawn sketch &quot;system diagram&quot; showing the ground poin=
ts, wire routing of the earth electrode loop antenna, please visit my blog=
 at <a href=3D"http://g3xbm-qrp.blogspot.com/">http://g3xbm-qrp.blogspot.c=
om/</a><br>

<br>These notes are to clarify the diagram...<br><ul><li>I&#39;m using thi=
s earth electrode &quot;antenna&quot; to TX with on 500kHz and on sub-9kHz=
. It has not been tried on 136kHz (yet). </li><li>The wire runs down the=
 garden fence (1.5m above ground) from the far electrode (1.5m in the soil=
) then coming up along=20
the study roof to the upstairs bedroom where it connects to the inner of=
 a=20
coax cable. The outer of the coax is grounded to the copper pipes of the=
=20
central heating system at this point. </li><li>The copper pipes within the=
 house eventually join with=20
the water pipes in the street (to the right in the diagram). </li><li>From=
 the feed point, a 10m long coax goes through the house to the front bedro=
om where
 I have my 5W out transverter for 500kHz and my 4W sub-9kHz TX beacon. </l=
i><li>No attempt at matching this has been made at all on 500kHz - I just=
 connected to the wire and radiator
 at the end of the coax. On sub-9kHz I use a step-up transformer to match=
 to around 40-60 ohms resistive (measured).</li><li>The local rock (below=
 about 2m of limy soil) is chalky &quot;clunch&quot;.</li><li>On 500kHz I&=
#39;ve measured 34V with a diode probe at the feed point at the=20
end of the coax in the rear bedroom (LHS of the house in the diagram)=20
where=20
it is grounded to the radiator and the wire starts its journey down the=20
garden.</li></ul>

Questions:<br><ol><li>Now, how big is the loop thus formed? </li><li>How=
 much of this is within the=20
ground?</li><li>What is the 500kHz ERP likely to be?<br></li></ol>

Best report this evening so far is -26dB S/N from G0KTN at 210kms.<br>
<br>
73s<br>
Roger G3XBM<br>-- <br><a href=3D"http://g3xbm-qrp.blogspot.com/">http://g3=
xbm-qrp.blogspot.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://w=
ww.youtube.com/user/g3xbm</a><br>
G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088<br>

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