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<p>Laurie Mayhead wrote:
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<font face="Arial"><font size=-1>Hi
Tom,</font></font><font face="Arial"><font size=-1>Grounding is the big
problem at LF as I am sure you know.Radial systems that would be effective
on 40, 80,or even 160 are impossible (100 X quarter wavelength makes the
mind boggle)Ground penetration and the extent of the near field means that
modest radial systems and short ground rods are virtually useless,and I
have tried,I currently have about 500m of buried wire and 30 four
foot rods.I recon I could disconnect most of this with no effect.I think
that the same would apply to burried sheets of metal unless they were several
hundred feet square ! Re. the water table Fresh water is an insulator
so no use. In the UK this winter the water table was on the surface,with
no measurable difference to loss resistance. I live near salt water and
a connection to the sea does help but only a little. For the Transatlantic
tests I ran out 3 radial wires of about 150 feet to 4 ft rods in sea water
. One helped but the others added nothing. So use the biggest longest
system you can find ie mains earth, water supply etc. but dont waste too
much time with buried wires! far better to put more WIRE IN THE AIR.I have
a theory that the top load should have as large a Footprint as possible.In
my case the top load is 10X the length of the vert section.It does not
need to be in a straight line and can zig-zag if necessesary. Rik
ON7YD has written this up in his "Antennas for 136kHz . see <a href="http://www.qsl.net/on7yd/">www.qsl.net/on7yd/</a></font></font><font face="Arial"><font size=-1>Hpoe
this some help. 73s Laurie.</font></font></blockquote>
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