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Date: Thu, 23 Jun 2011 09:43:11 +0100
Message-ID: <BANLkTim0jdkkmyKJ2WSi_zitWZhCh303CQ@mail.gmail.com>
From: Roger Lapthorn <rogerlapthorn@gmail.com>
To: rsgb_lf_group@blacksheep.org, sub9khz@yahoogroups.com
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Subject: LF: Earth mode and pipes
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It is some while since I last did any earth mode (conduction through the
ground) tests although I intend to resume these in a few weeks' time after
my holiday to Iceland. One of the tests will be earth mode at much higher
frequencies such as around 30 and 70kHz as well as at even lower frequencies
below 100Hz. I will try not to trigger WW3 by TXing around 82Hz though.

Today I noticed some workmen in the road outside my house with measuring kit
and listening gear. They were checking for leaks in water pipes which occur
usually where sections of pipe are linked. As I'd always assumed my earth
mode was utilities assisted via the metal water pipes from my house and in
the road I asked the question what sort of pipes were in the road. I was
surprised to hear these are not metal at all but are *asbestos
cement*pipes. The did not believe any tracer wires were present
either.

So, I am a bit puzzled now about what exactly my earth mode signals are
coupling into. All the indications were that I was using the water pipes but
now I have some doubts. The other utilities in the road are electricity, gas
and CATV which is fibre optic. Phones come in via overhead wires.  I think
the answer is that the coupling to buried utilities must be more complex
than I had assumed and that the earth mode signal is coupled into a variety
of pipes and cables.

73s
Roger G3XBM

-- 
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm
https://sites.google.com/site/sub9khz/

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It is some while since I last did any earth mode (conduction through the gr=
ound) tests although I intend to resume these in a few weeks&#39; time afte=
r my holiday to Iceland. One of the tests will be earth mode at much higher=
 frequencies such as around 30 and 70kHz as well as at even lower frequenci=
es below 100Hz. I will try not to trigger WW3 by TXing around 82Hz though.<=
br>
<br>Today I noticed some workmen in the road outside my house with measurin=
g kit and listening gear. They were checking for leaks in water pipes which=
 occur usually where sections of pipe are linked. As I&#39;d always assumed=
 my earth mode was utilities assisted via the metal water pipes from my hou=
se and in the road I asked the question what sort of pipes were in the road=
. I was surprised to hear these are not metal at all but are <b>asbestos ce=
ment</b> pipes. The did not believe any tracer wires were present either.<b=
r>
<br>So, I am a bit puzzled now about what exactly my earth mode signals are=
 coupling into. All the indications were that I was using the water pipes b=
ut now I have some doubts. The other utilities in the road are electricity,=
 gas and CATV which is fibre optic. Phones come in via overhead wires.=A0 I=
 think the answer is that the coupling to buried utilities must be more com=
plex than I had assumed and that the earth mode signal is coupled into a va=
riety of pipes and cables. <br>
<br>73s<br>Roger G3XBM<br clear=3D"all"><br>-- <br><a href=3D"http://g3xbm-=
qrp.blogspot.com/" target=3D"_blank">http://g3xbm-qrp.blogspot.com/</a><br>=
<a href=3D"http://www.g3xbm.co.uk" target=3D"_blank">http://www.g3xbm.co.uk=
</a><br>
<a href=3D"http://www.youtube.com/user/g3xbm" target=3D"_blank">http://www.=
youtube.com/user/g3xbm</a><br><a href=3D"https://sites.google.com/site/sub9=
khz/" target=3D"_blank">https://sites.google.com/site/sub9khz/</a><br><br>

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