Return-Path: Received: (qmail 23438 invoked from network); 5 Jun 2001 12:39:09 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by excalibur-qfe1-smtp-plusnet.harl.plus.net with SMTP; 5 Jun 2001 12:39:09 -0000 Received: (qmail 19040 invoked from network); 5 Jun 2001 12:38:45 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 5 Jun 2001 12:38:45 -0000 Content-Transfer-Encoding: 8bit Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 157FzU-0000gB-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 05 Jun 2001 13:31:20 +0100 Received: from bob.dera.gov.uk ([192.5.29.90]) by post.thorcom.com with esmtp (Exim 3.16 #2) id 157FzS-0000g6-00 for rsgb_lf_group@blacksheep.org; Tue, 05 Jun 2001 13:31:18 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: by bob.dera.gov.uk; (8.8.8/1.3/10May95) id NAA32766; Tue, 5 Jun 2001 13:35:18 +0100 (BST) Received: (qmail 11386 invoked from network); 5 Jun 2001 13:24:21 -0000 Received: from gauntlet.mail.dera.gov.uk (172.16.9.10) by baton.dera.gov.uk with SMTP; 5 Jun 2001 13:24:21 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: by gauntlet.mail.dera.gov.uk; id NAA04455; Tue, 5 Jun 2001 13:16:38 GMT Received: from unknown(10.71.64.31) by gauntlet.mail.dera.gov.uk via smap (3.2) id xma004019; Tue, 5 Jun 01 13:15:28 GMT Received: from mailex.dera.gov.uk (unverified) by mailguard.dera.gov.uk (Content Technologies SMTPRS 4.1.5) with SMTP id for ; Tue, 5 Jun 2001 13:38:14 +0100 Received: (qmail 1138 invoked from network); 5 Jun 2001 12:20:29 +0100 Received: from softdnserror (HELO cchecker.dstl.gov.uk) (192.168.248.52) by mailex.dstl.gov.uk with SMTP; 5 Jun 2001 11:20:29 -0000 Received: from FRN-MAIL-R1.dstl.gov.uk (unverified) by cchecker.dstl.gov.uk (Content Technologies SMTPRS 4.1.2) with ESMTP id for ; Tue, 5 Jun 2001 12:20:31 +0100 Received: by frn-mail-r1.dstl.gov.uk with Internet Mail Service (5.5.2650.21) id ; Tue, 5 Jun 2001 13:28:45 +0100 Message-ID: <7D653C9C42F5D411A27C00508BF8803D55C4B6@pdw-mail-r1.dstl.gov.uk> From: "Talbot Andrew" To: rsgb_lf_group@blacksheep.org Subject: LF: RE: Re. 73KHz T/A Date: Tue, 5 Jun 2001 13:28:48 +0100 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2650.21) Content-Type: text/plain; charset=iso-8859-1; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Could this path be enhanced by the Earth / Ionosphere waveguide propagation mode, prevalent at lower frequencies. I know it is rather too high frequency to be normally considered for this mode, but with a D layer 'height' of around 75km (is that right ?) the waveguide guide width is something like 8 wavelengths so something may be feasible. Just a thought Andy G4JNT > Assuming Laurie and John's reports check out OK, this will be > something quite extraordinary. Given the noise level on 73k, and > the reduced ERP available on the band, propagation losses would > have to be very much less than on 136k - I wonder what the -- The Information contained in this E-Mail and any subsequent correspondence is private and is intended solely for the intended recipient(s). For those other than the recipient any disclosure, copying, distribution, or any action taken or omitted to be taken in reliance on such information is prohibited and may be unlawful.