Return-Path: Received: from mtain-df11.r1000.mx.aol.com (mtain-df11.r1000.mx.aol.com [172.29.64.223]) by air-df05.mail.aol.com (v129.4) with ESMTP id MAILINDF054-5ef54c3f3c8d175; Thu, 15 Jul 2010 12:51:25 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-df11.r1000.mx.aol.com (Internet Inbound) with ESMTP id 5D1AF3800009E; Thu, 15 Jul 2010 12:51:23 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OZRdE-0008Mk-Bn for rs_out_1@blacksheep.org; Thu, 15 Jul 2010 17:49:56 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OZRdD-0008Mb-L2 for rsgb_lf_group@blacksheep.org; Thu, 15 Jul 2010 17:49:55 +0100 Received: from smtp.qtxt.dns-iol.com ([195.200.78.13]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OZRdC-0004pt-Tc for rsgb_lf_group@blacksheep.org; Thu, 15 Jul 2010 17:49:55 +0100 Received: (qmail 23838 invoked by uid 507); 15 Jul 2010 18:49:30 +0200 Received: from unknown (HELO ?192.168.1.101?) (john.rabson@numeo.fr@217.67.155.178) by smtp.qtxt.dns-iol.com with SMTP; 15 Jul 2010 18:49:30 +0200 Mime-Version: 1.0 (Apple Message framework v1081) From: John Rabson X-Priority: 3 In-Reply-To: Date: Thu, 15 Jul 2010 18:52:57 +0200 Message-Id: <3F71CB69-5F2E-4BEE-BB5E-651DA77CC39E@numeo.fr> References: <4C363DCD.303@iup.uni-heidelberg.de>,<4C3650A1.6040104@iup.uni-heidelberg.de> ,<4C3DA75D.80407@iup.uni-heidelberg.de> ,<263121BD51374246B3F184A43B2E9619@JimPC> <4C3E27D4.3060407@iup.uni-heidelberg.de> To: rsgb_lf_group@blacksheep.org X-Mailer: Apple Mail (2.1081) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: RE: DLF passive received with earth antenna Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none 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-sid: 3039ac1d40df4c3f3c8b57d9 X-AOL-IP: 193.82.116.20 X-AOL-SPF: domain : blacksheep.org SPF : none Members of the Cave Radio & Electronics Group have been using and investig= ating earth loop antennas for some time. The theoretical basis of such an= antenna has not been clear to us, but Dr David Gibson of CREG is proposin= g to give the following lecture at the Hidden Earth conference in the UK= this autumn. How earth-current antennas really work -------------------------------------- With cave radio equipment such as the HeyPhone and Nicola system there has been a trend away from the use of induction loop antennas towards earth-current antennas, i.e. long wires grounded at both ends. However, the popular explanation for how these antennas work is fallacious. They do not operate by allowing the current to flow in a 'big loop' in the ground and in fact, they do not depend, fundamentally, on current flow in the ground at all. The fact that the popular explanation is wrong is important because, if we do not understand how the antenna works, it is difficult to know the best way to use it, or how to design a better one. Back in 2003, I wrote an article for the CREG journal entitled 'What We Don't Know About Earth-Current Propagation'. It has taken me some time to get to grips with the problem but this talk will now go some way to filling in the gaps in this knowledge and will describe a method of experimentally rating earth-current antennas for effectiveness. --=20 David Gibson