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Message-ID: <130055.37036.qm@web28108.mail.ukl.yahoo.com>
Date: Thu, 11 Mar 2010 13:45:49 -0800 (PST)
From: M0FMT <m0fmt@yahoo.co.uk>
To: rsgb_lf_group@blacksheep.org
In-Reply-To: <9afca2641003111254v47a0363eicdee899d7c2b3431@mail.gmail.com>
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Subject: Re: LF: Induction DX?
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Try
http://www.marcspages.co.uk/tech/index.htm
73 es GL petefmt

--- On Thu, 11/3/10, Roger Lapthorn <rogerlapthorn@gmail.com> wrote:


From: Roger Lapthorn <rogerlapthorn@gmail.com>
Subject: LF: Induction DX?
To: rsgb_lf_group@blacksheep.org
Date: Thursday, 11 March, 2010, 20:54


If I've asked this before please forgive me....

With all the discussion recently on how to radiate a signal on sub-9kHz I'=
m left wondrering how far, practically, one could expect to get simply wit=
h sub-9kHz magnetic induction using multi-turn loops at each end?=A0 The=
 Cave Radio Group (CREG) may have some answers but I'm not a subscriber so=
 can't read any of their documents.=20

It would be quite easy for anyone to generate 50-100W or so and feed this=
 into a largish diameter multi-turn loop. Correctly aligned and with a sim=
ilar loop at the far end and using decent weak signal processing just what=
 range might be possible using modes like QRSS or WSPR? Has anyone tried=
 this to see just what is practical, simply using induction fields?=20

Also, can anyone point me to some webpages with some practical audio frequ=
ency induction communication systems? There are lots of references to near=
 field comms for on-body and inter-device comms but I've not found much ot=
herwise.

73s=20
Roger G3XBM


--=20
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/G3XBM
G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088



     =20

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<table cellspacing=3D"0" cellpadding=3D"0" border=3D"0" ><tr><td valign=3D=
"top" style=3D"font: inherit;">Try<BR><A href=3D"http://www.marcspages.co.=
uk/tech/index.htm">http://www.marcspages.co.uk/tech/index.htm</A><BR>73 es=
 GL petefmt<BR><BR>--- On <B>Thu, 11/3/10, Roger Lapthorn <I>&lt;rogerlapt=
horn@gmail.com&gt;</I></B> wrote:<BR>
<BLOCKQUOTE style=3D"BORDER-LEFT: rgb(16,16,255) 2px solid; PADDING-LEFT:=
 5px; MARGIN-LEFT: 5px"><BR>From: Roger Lapthorn &lt;rogerlapthorn@gmail.c=
om&gt;<BR>Subject: LF: Induction DX?<BR>To: rsgb_lf_group@blacksheep.org<B=
R>Date: Thursday, 11 March, 2010, 20:54<BR><BR>
<DIV id=3Dyiv939727884><I>If I've asked this before please forgive me....<=
/I><BR clear=3Dall><BR>With all the discussion recently on how to<I> radia=
te</I> a signal on sub-9kHz I'm left wondrering how far, practically, one=
 could expect to get simply with sub-9kHz magnetic induction using multi-t=
urn loops at each end?&nbsp; The Cave Radio Group (CREG) may have some ans=
wers but I'm not a subscriber so can't read any of their documents. <BR><B=
R>It would be quite easy for anyone to generate 50-100W or so and feed thi=
s into a largish diameter multi-turn loop. Correctly aligned and with a si=
milar loop at the far end and using decent weak signal processing just wha=
t range might be possible using modes like QRSS or WSPR? Has anyone tried=
 this to see just what is practical, simply using induction fields? <BR><B=
R>Also, can anyone point me to some webpages with some practical audio fre=
quency induction communication systems? There are lots of references to ne=
ar field
 comms for on-body and inter-device comms but I've not found much otherwis=
e.<BR><BR>73s <BR>Roger G3XBM<BR><BR><BR>-- <BR><A href=3D"http://g3xbm-qr=
p.blogspot.com/" rel=3Dnofollow target=3D_blank>http://g3xbm-qrp.blogspot.=
com/</A><BR><A href=3D"http://www.g3xbm.co.uk/" rel=3Dnofollow target=3D_b=
lank>http://www.g3xbm.co.uk</A><BR><A href=3D"http://www.youtube.com/user/=
G3XBM" rel=3Dnofollow target=3D_blank>http://www.youtube.com/user/G3XBM</A=
><BR>G3XBM &nbsp; &nbsp;GQRP 1678 &nbsp; &nbsp; &nbsp;ISWL G11088<BR></DIV=
></BLOCKQUOTE></td></tr></table><br>



     =20

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