[Milsurplus] VLF Reception and ELF

[Dennis Kidder]

For those interested in VLF and below I would direct you to an outstanding Web site from Italy:  http://www.vlf.it/

This has to be one of the most comprehensive sites dedicated VLF and below on the Web.  One of the truly valuable things that I learned about from this site is a freeware Windows application called "Spectrum Lab."  This was developed by a German ham - DL4YHF - and is a free download.  Depending on the max sample rate of your PC's sound card, you can observe the spectrum practically down to DC.  It is a formidable tool to have!  In 2005, I successfully used Spectrum Lab to receive the July transmission from SAQ in the Mojave desert in California -- something that I have not been able to duplicate since and apparently no one else has, either!  One of the nice features of Spectrum Lab is the use of "plug ins" for special applications.  Someone has since developed an SAQ receiver plugin that makes your computer into a receiver rather than just a spectrum display.

You will find hours of reading on the vlf.it site.  Discussion topics range from detection of earthquake precursors (this thread) to the VLF and ELF transmissions of Jim Creek, NAA and our old friend, Clam Lake in Wisconsin.

I might add that I have a number of VLF receivers in my radio shack ranging from an SP-600-L to a Collins HF-2050.  The '2050 shines as a VLF receiver ... NAA boils into So Cal!

One last thought with regards to the fabrication of the antenna from the SA article.  The original article utilized a very large ferrite rod.  Rebar was a suggested alternative.  The designs at vlf.it use strap Iron, packed into a section of PVC pipe.  While the permeability of the strap Iron is not that of the ferrite rod, it is quite effective, readily available and inexpensive.  I think the real challenge is finding that 20 miles of 40 AWG to wind the beast.

I hope you find the VLF site useful and entertaining.

Thanks and 73!

-dennis W6DQ




________________________________
From: Gary Pewitt <garypewitt at centurytel.net>
To: Rod Hogg <revcom at wbsnet.org>
Cc: boatanchors at mailman.qth.net; milsurplus at mailman.qth.net
Sent: Mon, January 18, 2010 7:16:02 PM
Subject: Re: [Milsurplus] VLF Reception and ELF

Rod, I remember reading that article in S.A. magazine years ago.  Isn't 
that antenna a monster?  I'd love to have a copy if you have it 
digitized.  Now where can I get some 2 inch diameter re-bar? :-\    Or 
the preferred metal (which I can't remember the name of).
And was that about 5000 turns or 50,000 turns?

73  Gary  N9ZSV      garypewitt at centurytel.net




n 1/18/2010 3:46 PM, Rod Hogg wrote:
> About a week ago there were several threads on VLF stations, reception etc.
> Got me thinking, with current happenings in Haiti and else where, I looked
> back in my archives and found an article for constructing an ELF (0.1 to
> 20Hz) receiver.  It can be used to detect earthquake waves.  Came from
> "Conformity" magazine, (July 2002) a reprint from "Scientific American" by
> Shawn Carlson (May 1996).
>
> Anyone interested?
>
> Rod
> KØEQH
>
>
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