Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dg02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 02B78380000B8; Mon, 15 Aug 2011 15:14:42 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Qt2bh-0007Iy-19 for rs_out_1@blacksheep.org; Mon, 15 Aug 2011 20:13:53 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Qt2bg-0007Ip-9c for rsgb_lf_group@blacksheep.org; Mon, 15 Aug 2011 20:13:52 +0100 Received: from mail-gy0-f171.google.com ([209.85.160.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Qt2bd-0001TI-IC for rsgb_lf_group@blacksheep.org; Mon, 15 Aug 2011 20:13:52 +0100 Received: by gye5 with SMTP id 5so4540752gye.16 for ; Mon, 15 Aug 2011 12:13:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=MpY0KC4FioaDuG2zDrGFWuYaI68DRRiCFYtMJ7TBpwM=; b=g1sdMfczQCQ1A/A7Xy3UpXggnQYcVgQ4ZG+DnAzhQvVEKZw5BIX/gHXwCQeWL6fEo1 6wp3TQ8NGUC255lPyBw0HfPuzGyPwqLYZPPCtfLOvLZzkjoRYtDWH/CTpiH4iXraL11r 7znrVmBjeU67PdY3Pw32NGQickW0J0ZoYUZFo= MIME-Version: 1.0 Received: by 10.142.226.2 with SMTP id y2mr1436493wfg.449.1313435622348; Mon, 15 Aug 2011 12:13:42 -0700 (PDT) Received: by 10.142.188.7 with HTTP; Mon, 15 Aug 2011 12:13:42 -0700 (PDT) In-Reply-To: References: <8F12A13F-4174-4C0F-8916-1543A69C2E65@gmail.com> <17BB4B3F-F338-4973-8F87-BD710C9C1539@numeo.fr> Date: Mon, 15 Aug 2011 20:13:42 +0100 Message-ID: From: Roger Lapthorn To: rsgb_lf_group@blacksheep.org X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Ferrite rods Content-Type: multipart/alternative; boundary=000e0cd29c42b4963c04aa900f06 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=HTML_30_40, HTML_FONTCOLOR_UNSAFE,HTML_MESSAGE autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:446055008:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m209.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d410a4e4970224439 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --000e0cd29c42b4963c04aa900f06 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thanks Steve and John for information. Mal - thanks for your always helpful comments. We love them. 73s Roger G3XBM On 15 August 2011 18:45, Steve, g4vbd wrote: > Guys > Its =A349.00 from this web site > > > http://www.lulu.com/product/paperback/channel-characterisation-and-system= -design-for-sub-surface-communications/11253100 > > too expensive for me - but if you find a pdf then I'd be interested as we= ll > Found this though > > Electrode Contact Impedance Measurement in Through-The-Earth Communicatio= ns > > http://dcis2009.unizar.es/FILES/CR2/p30.pdf > > regards > Steve, g4vbd > > > > On Mon, Aug 15, 2011 at 12:02 PM, Roger Lapthorn wrote: > >> Is this PhD document publically available as a PDF John? >> >> 73s >> Roger G3XBM >> >> >> On 15 August 2011 11:26, John Rabson wrote: >> >>> There is an extensive discussion of ferrite rod antennas in Chapter 4 o= f: >>> >>> Gibson, David (2004) Channel Characterisation and System Design >>> for Sub-Surface Communications PhD thesis, Leeds University 2004. >>> >>> John >>> F5VLF >>> >>> On 15 Aug 2011, at 09:46CEST, Roger Lapthorn wrote: >>> >>> > Although I've little experience of ferrite rods on LF receive I did >>> wind my 600uH 500kHz ATU loading coil for my 5w transverter on one. Wi= th >>> just a 5m top loaded vertical it worked well without saturation problem= s >>> when sitting on the bedroom table. At QRP it is less lossy as less wir= e is >>> needed. >>> > >>> > People have successfully engineered (single turn I think) ferrite rod= s >>> as TX antennas for 10MHz QRPp WSPR. Somewhere I have some information o= n >>> this. As long as saturation is avoided there is some mileage for HF TX >>> applications in very compact QRP stations. >>> > >>> > Worth some experiments on LF receive Stefan. >>> > >>> > 73s >>> > Roger G3XBM >>> > >>> > Via my iPod Touch 4g 2.4GHz handheld. >>> > >>> >>> >>> >> >> >> -- >> http://g3xbm-qrp.blogspot.com/ >> http://www.g3xbm.co.uk >> http://www.youtube.com/user/g3xbm >> https://sites.google.com/site/sub9khz/ >> >> > --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm https://sites.google.com/site/sub9khz/ --000e0cd29c42b4963c04aa900f06 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thanks Steve and John for information.

Mal - thanks for your always = helpful comments. We love them.

73s
Roger G3XBM

On 15 August 2011 18:45, Steve, g4vbd &l= t;steve.g4vbd@sky.com>= wrote:
Guys
Its =A349.00 from this = web site
=A0
=A0
too expensive for me - but if you find a pdf then I'= d be interested as well
Found this though

Electrode Conta= ct Impedance Measurement in Through-The-Earth Communications

Steve, g4vbd


=A0
On Mon, Aug 15, 2011 at 12:02 PM, R= oger Lapthorn <rogerlapthorn@gmail.com> wrote:
Is this PhD document publically available as a PDF John?=

73s
Roger G3XBM


On 15 August 2011 11:26, John Rabson <john.rabson@numeo.fr> wrote:
There is an extensive discussion of ferrite rod antennas= in Chapter 4 of:

=A0 =A0 =A0 =A0Gibson, David (2004) Channel Characterisation and System De= sign for Sub-Surface Communications PhD thesis, Leeds University 2004.

John
F5VLF

On 15 Aug 2011, at 09:46CEST, Roger Lapthorn wrote:

> Although I've little experience of ferrite rods on LF receive I di= d wind my 600uH 500kHz ATU loading coil for my 5w transverter on one. =A0Wi= th just a 5m top loaded vertical it worked well without saturation problems= when =A0sitting on the bedroom table. At QRP it is less lossy as less wire= is needed.
>
> People have successfully engineered (single turn I think) ferrite rods= as TX antennas for 10MHz QRPp WSPR. Somewhere I have some information on t= his. As long as saturation is avoided there is some mileage for HF TX appli= cations in very compact QRP stations.
>
> Worth some experiments on LF receive Stefan.
>
> 73s
> Roger G3XBM
>
> Via my iPod Touch 4g 2.4GHz handheld.
>





--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.= youtube.com/user/g3xbm
https://sites.google.com/site/sub9khz/





--
http://g3xbm-qrp.blogspot= .com/
http://ww= w.g3xbm.co.uk
http://www.= youtube.com/user/g3xbm
https://sites.google.com/site/sub9khz/

--000e0cd29c42b4963c04aa900f06--