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From: Roger Lapthorn <rogerlapthorn@gmail.com>
Message-Id: <E6B742ED-5AFF-4700-8B5E-3D5CB9AA297E@gmail.com>
Date: Thu, 14 Apr 2011 21:32:02 +0100
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 "rsgb_lf_group@blacksheep.org" <rsgb_lf_group@blacksheep.org>
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Subject: LF: More Earth-mode tests at 1.095kHz
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Today I did some more utilities assisted earth mode (UAEM) tests. Basicall=
y I wanted to see if I could detect my 5W signal some way from the roadsid=
es by using a pair of earth rods separated by about 20m rather than the us=
ual 80cm 30turn loop which fails to detect a signal at any distance from=
 the roads.  Testing up to 20m away from the roadside all tests were negat=
ive again, as they also were with a grounded electrode pair straddling the=
 road, which surprised me: I thought this would have behaved as a tightly=
 coupled loop around any pipes in the road, but this did not give any sign=
al at all - not even the faintest trace.=20

What worked best of all was a single turn untuned wire loop, enclosing  ab=
out 20 sq m, laid flat across the road surface.  With this, I achieved ver=
y good QRSS3 copy in 0.73Hz BW at all the usual test sites out to 5.1km.=
 This is easy to put out each time and safe for farm vehicles to drive ove=
r! =20

As this arrangement was the most sensitive yet for UAEM I tried looking fo=
r the signal 6km away from home, but nothing was seen in 0.73Hz BW and QRS=
S3. When the pipes stop the signal just dies.=20

VLF work will now stop for about 10 days as we have grandchildren here to=
 stay and occupying our time and the shack bedroom. I may be able to look=
 for Stefan if he is testing at the weekend.=20

73s
Roger G3XBM

Via my 2.4GHz handheld (iPod Touch 4g)