Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dl05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 9CEE938000098; Mon, 15 Aug 2011 15:28:04 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Qt2od-0007cB-38 for rs_out_1@blacksheep.org; Mon, 15 Aug 2011 20:27:15 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Qt2oc-0007c2-IQ for rsgb_lf_group@blacksheep.org; Mon, 15 Aug 2011 20:27:14 +0100 Received: from out1.ip09ir2.opaltelecom.net ([62.24.128.245]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Qt2oZ-0001rd-JJ for rsgb_lf_group@blacksheep.org; Mon, 15 Aug 2011 20:27:14 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AucAAKVySU5cF/r8/2dsb2JhbABClEQDhAGHQgGICniBOwUBAQMBAQgBAQNJAiYGAQEDBQIBAxEEAQEKJRQBBAgSBhYIBhMKAQICAQGHXwICuSCGRwSCUYRflViHAA X-IronPort-AV: E=Sophos;i="4.67,375,1309734000"; d="scan'208,217";a="487453659" Received: from host-92-23-250-252.as13285.net (HELO xphd97xgq27nyf) ([92.23.250.252]) by out1.ip09ir2.opaltelecom.net with SMTP; 15 Aug 2011 20:27:05 +0100 Message-ID: <007801cc5b81$478acf90$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: <8F12A13F-4174-4C0F-8916-1543A69C2E65@gmail.com><17BB4B3F-F338-4973-8F87-BD710C9C1539@numeo.fr> Date: Mon, 15 Aug 2011 20:26:49 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Ferrite rods Content-Type: multipart/alternative; boundary="----=_NextPart_000_0075_01CC5B89.A90C6230" 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: 0:2:468868224:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d4ad34e49734340ed X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ------=_NextPart_000_0075_01CC5B89.A90C6230 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable KEEP LEFT !! ----- Original Message -----=20 From: Roger Lapthorn=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Monday, August 15, 2011 8:13 PM Subject: Re: LF: Ferrite rods 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 well Found this though Electrode Contact Impedance Measurement in Through-The-Earth = Communications http://dcis2009.unizar.es/FILES/CR2/p30.pdf regards Steve, g4vbd =20 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 of: 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. With just a 5m top loaded vertical it worked well without = saturation problems when sitting 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 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. > --=20 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/ ------=_NextPart_000_0075_01CC5B89.A90C6230 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
KEEP LEFT !!
 
----- Original Message -----
From:=20 Roger=20 Lapthorn
Sent: Monday, August 15, 2011 = 8:13=20 PM
Subject: Re: LF: Ferrite = rods

Thanks Steve and John for information.

Mal - = thanks for=20 your always helpful comments. We love them.

73s
Roger = G3XBM

On 15 August 2011 18:45, Steve, g4vbd <steve.g4vbd@sky.com> = wrote:
Guys
Its =A349.00 from this web site
 
http://www.lulu.com/product/paperback/channel-characteris= ation-and-system-design-for-sub-surface-communications/11253100
=
 
too expensive for me - but if you find a pdf then I'd be = interested as=20 well
Found this though

Electrode Contact Impedance Measurement in Through-The-Earth=20 Communications

 
 
regards
Steve, g4vbd


 
On Mon, Aug 15, 2011 at 12:02 PM, Roger = Lapthorn=20 <rogerlapthorn@gmail.com> wrote:
Is=20 this PhD document publically available as a PDF = John?

73s
Roger=20 G3XBM


On 15 August 2011 11:26, John Rabson = <john.rabson@numeo.fr> wrote:
There=20 is an extensive discussion of ferrite rod antennas in Chapter 4=20 of:

       Gibson, David (2004) = Channel=20 Characterisation and System Design for Sub-Surface = Communications PhD=20 thesis, Leeds University 2004.

John
F5VLF

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

>=20 Although I've little experience of ferrite rods on LF receive I = did wind=20 my 600uH 500kHz ATU loading coil for my 5w transverter on one.=20  With just a 5m top loaded vertical it worked well without=20 saturation problems when  sitting on the bedroom table. At = QRP it=20 is less lossy as less wire is needed.
>
> People = have=20 successfully engineered (single turn I think) ferrite rods as TX = antennas for 10MHz QRPp WSPR. Somewhere I have some information = on this.=20 As long as saturation is avoided there is some mileage for HF TX = applications in very compact QRP stations.
>
> Worth = some=20 experiments on LF receive Stefan.
>
> 73s
> = Roger=20 G3XBM
>
> Via my iPod Touch 4g 2.4GHz=20 = 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://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm
https://sites.google.com/site/sub9khz/

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