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Date: Thu, 11 Mar 2010 20:54:06 +0000
Message-ID: <9afca2641003111254v47a0363eicdee899d7c2b3431@mail.gmail.com>
From: Roger Lapthorn <rogerlapthorn@gmail.com>
To: rsgb_lf_group@blacksheep.org
DomainKey-Status: good (testing) 
Subject: LF: Induction DX?
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*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
with sub-9kHz magnetic induction using multi-turn loops at each end?  The
Cave Radio Group (CREG) may have some answers but I'm not a subscriber so
can't read any of their documents.

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
similar 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?

Also, can anyone point me to some webpages with some practical audio
frequency 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
otherwise.

73s
Roger G3XBM


-- 
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/G3XBM
G3XBM    GQRP 1678      ISWL G11088

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<i>If I&#39;ve asked this before please forgive me....</i><br clear=3D"all=
"><br>With all the discussion recently on how to<i> radiate</i> a signal=
 on sub-9kHz I&#39;m left wondrering how far, practically, one could expec=
t to get simply with sub-9kHz magnetic induction using multi-turn loops at=
 each end?=A0 The Cave Radio Group (CREG) may have some answers but I&#39;=
m not a subscriber so can&#39;t read any of their documents. <br>
<br>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 similar loop at the far end and using decent weak signal processing jus=
t 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?=
 <br>
<br>Also, can anyone point me to some webpages with some practical audio=
 frequency induction communication systems? There are lots of references=
 to near field comms for on-body and inter-device comms but I&#39;ve not=
 found much otherwise.<br>
<br>73s <br>Roger G3XBM<br><br><br>-- <br><a href=3D"http://g3xbm-qrp.blog=
spot.com/">http://g3xbm-qrp.blogspot.com/</a><br><a href=3D"http://www.g3x=
bm.co.uk">http://www.g3xbm.co.uk</a><br><a href=3D"http://www.youtube.com/=
user/G3XBM">http://www.youtube.com/user/G3XBM</a><br>
G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088<br>

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