Return-Path: Received: from mtain-md05.r1000.mx.aol.com (mtain-md05.r1000.mx.aol.com [172.29.96.89]) by air-di01.mail.aol.com (v127_r1.1) with ESMTP id MAILINDI014-eab94b961aa732; Tue, 09 Mar 2010 04:53:43 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-md05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 1C883380000C6; Tue, 9 Mar 2010 04:53:42 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Now6s-0003uD-PO for rs_out_1@blacksheep.org; Tue, 09 Mar 2010 09:52:18 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Now6s-0003u4-Ds for rsgb_lf_group@blacksheep.org; Tue, 09 Mar 2010 09:52:18 +0000 Received: from mhost02h.leeds.ac.uk ([129.11.77.151]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Now6q-0000R7-Mn for rsgb_lf_group@blacksheep.org; Tue, 09 Mar 2010 09:52:18 +0000 Received: from APOLLO1.ds.leeds.ac.uk (apollo1.leeds.ac.uk [129.11.5.4]) by mhost02h.leeds.ac.uk (8.14.3/8.14.3) with ESMTP id o299pfg1016087 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT) for ; Tue, 9 Mar 2010 09:52:10 GMT Received: from HERMES8.ds.leeds.ac.uk ([fe80::39ce:23e:d0b5:7e24]) by APOLLO1.ds.leeds.ac.uk ([129.11.5.4]) with mapi; Tue, 9 Mar 2010 09:52:04 +0000 From: Chris Trayner To: "rsgb_lf_group@blacksheep.org" Date: Tue, 9 Mar 2010 09:52:02 +0000 Thread-Topic: LF: Through-The- Earth Communication Thread-Index: Acq/biuic6g7zjHyR2GNgty0Odf8Ig== Message-ID: References: <31711175.2399083.1268126158633.JavaMail.fmail@mwmweb080> In-Reply-To: <31711175.2399083.1268126158633.JavaMail.fmail@mwmweb080> Accept-Language: en-US, en-GB Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US, en-GB MIME-Version: 1.0 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Through-The- Earth Communication 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=TO_ADDRESS_EQ_REAL 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: 3039ac1d60594b961aa62e7a X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) Dear Horst, Thanks for your post. > As RX-Antenna for 136 kHz it is not too bad. > On 500 kHz it does not really work. Such earth-loop antennas are more or less standard for cave radio. (AFAIK,= this started when Rob Gill G8DSU decided to try them at a Cave Radio and= Electronics Group field meeting, and they proved far better than wire loo= ps. The Cave Rescue groups later adopted them.) Cave radio is possibly nea= r-field induction, but we we using it in north England many years ago and= suddenly heard Finbar O'Connor on 73kHz from Ireland. Earth spikes certai= nly can make good antennas. 73, Chris G4OKW ----------------------- Dr Chris Trayner School of Electronic & Electrical Engineering, The University of Leeds, Leeds LS2 9JT, United Kingdom Tel: +44 113 34 32053 Fax: +44 113 34 32032