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Date: Mon, 02 Jun 2014 21:16:38 +0000
From: Paul Nicholson <vlf0403@abelian.org>
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Subject: Re: VLF: W4DEX trans-Atlantic at 8971 Hz
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Going east to west is much harder, maybe 20dB harder, thanks to
anisotropy of ionospheric reflection which is very significant
at VLF.

Mike Smith near Lynchburg, VA, has an excellent E-field rx at a
quiet location.  I have hopes he will put up orthogonal loops.
Mike uses the same VLF software as used here,

  http://abelian.org/vlfrx-tools/

Mike's VLF receiver is streamed online, see vlf35 'Forest' at

  http://abelian.org/vlf

and there is a temporary 8971.1 Hz spectrum updated every 30
mins at

  http://46.4.26.83/sp8971_vlf35.png

Uwe DJ8WX made determined attempts earlier in the year to reach
Lynchburg and I used every trick I could think of to search for
his signal in Mike's data, but I think we were still a few dB
under the noise.

Stefan wrote:

 > PS: 8.97 (+-), that was the _right_ frequency range *thumbs up*! :-)

Indeed, when operating at the limits of what is possible, the dB or
so difference between 8970 and 8270 becomes very significant.   The
European restriction to sub 8.3kHz is presumably to avoid lightning
detection networks.  But these would surely be unaffected by these
very weak amateur signals unless the tx was within a few km of
a meteorological receiver.   Perhaps with suitable representation
from national amateur radio organisations, the situation could be
re-considered.

--
Paul Nicholson
--