Return-Path: Received: (qmail 25023 invoked from network); 10 Feb 2003 11:41:45 -0000 Content-Transfer-Encoding: 8bit Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 10 Feb 2003 11:41:45 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 26822 invoked from network); 10 Feb 2003 11:41:38 -0000 Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 10 Feb 2003 11:41:38 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.12) id 18iCID-0001kr-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 10 Feb 2003 11:40:09 +0000 Received: from [147.197.200.9] (helo=hestia.herts.ac.uk) by post.thorcom.com with esmtp (Exim 4.12) id 18iCIC-0001ki-00 for rsgb_lf_group@blacksheep.org; Mon, 10 Feb 2003 11:40:08 +0000 Received: from gemini ([147.197.200.44] helo=gemini.herts.ac.uk) by hestia.herts.ac.uk with esmtp (Exim 3.22 #1) id 18iCHh-0006mV-00 for rsgb_lf_group@blacksheep.org; Mon, 10 Feb 2003 11:39:37 +0000 Received: from [147.197.232.252] (helo=rsch-15.herts.ac.uk) by gemini.herts.ac.uk with esmtp (Exim 3.33 #1) id 18iCHf-00020m-00 for rsgb_lf_group@blacksheep.org; Mon, 10 Feb 2003 11:39:36 +0000 Message-ID: <5.1.0.14.0.20030210111905.00ac0508@gemini.herts.ac.uk> X-Sender: mj9ar@gemini.herts.ac.uk X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Mon, 10 Feb 2003 11:39:34 +0000 To: rsgb_lf_group@blacksheep.org From: "James Moritz" In-reply-to: <00d501c2d0f0$2ff1cf20$0504210a@c.scope> MIME-Version: 1.0 X-MailScanner: No Virus detected Subject: Re: LF: Loran Content-Type: text/plain; charset=us-ascii; format=flowed X-Spam-Status: No, hits=-0.2 required=6.0tests=DEAR_SOMEBODY,IN_REP_TO,SPAM_PHRASE_01_02version=2.43 X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rsgb_lf_group-outgoing@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false Dear Hugh, LF Group, For an explanation of Loran C and other hyperbolic radio navigtion systems, take a look at http://webhome.idirect.com/~jproc/hyperbolic/ The Loran transmitters all operate on 100kHz, and transmit short pulses - this leads to the sidebands extending into the 136kHz bands. Usually, in SE England, you should be able to hear the rhythmic chattering sound under quiet band conditions at 136kHz - if not, you need to look into your RX sensitivity! The nearest TX is at Lessay on the french coast. Each Loran chain has a different pulse repetition frequency (GRI), so different parts of the world have different Loran lines. Because of the pulsed signal, the duty cycle is quite small, and the mean power is much less than the PEP. Cheers, Jim Moritz 73 de M0BMU