Return-Path: Received: (qmail 14274 invoked from network); 12 Jul 2001 09:34:48 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 12 Jul 2001 09:34:48 -0000 Received: (qmail 22721 invoked from network); 12 Jul 2001 09:33:26 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 12 Jul 2001 09:33:26 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 15KckI-0005Kk-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 12 Jul 2001 10:26:54 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from hestia.herts.ac.uk ([147.197.200.9]) by post.thorcom.com with esmtp (Exim 3.16 #2) id 15KckH-0005Kf-00 for rsgb_lf_group@blacksheep.org; Thu, 12 Jul 2001 10:26:53 +0100 Received: from gemini ([147.197.200.44] helo=gemini.herts.ac.uk) by hestia.herts.ac.uk with esmtp (Exim 3.22 #1) id 15KcjZ-0006I1-00 for rsgb_lf_group@blacksheep.org; Thu, 12 Jul 2001 10:26:09 +0100 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from [147.197.232.252] (helo=mj9ar) by gemini.herts.ac.uk with smtp (Exim 3.22 #2) id 15KcjU-0000zK-00 for rsgb_lf_group@blacksheep.org; Thu, 12 Jul 2001 10:26:04 +0100 From: "James Moritz" Organization: University of Hertfordshire To: rsgb_lf_group@blacksheep.org Date: Thu, 12 Jul 2001 10:27:39 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: LF: LF/Hyper test X-Mailer: Pegasus Mail for Win32 (v3.11) Message-ID: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Dear Walter, LF Group, Very interesting to hear about the "million-to-one" 9kHz <=> 10GHz cross-band QSO. As a rough rule, most of the antenna books use the distance lambda/2pi as the boundary between near field and far field of an antenna, although many other factors are involved. With about 33km wavelength, this puts the boundary at about 5.3km, so as Rik points out, some form of near-field coupling mode is probably involved - perhaps the mutual capacitance between antennas would be a good way of looking at it. It would be very interesting to see how results compared if a magnetic RX antenna was used, ie. ferrite rod or loop. I can see this will be a fertile ground for theories! Cheers, Jim Moritz 73 de M0BMU