Return-Path: Received: (qmail 21643 invoked from network); 7 Oct 2002 10:08:13 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 7 Oct 2002 10:08:13 -0000 Content-Transfer-Encoding: 8bit Received: (qmail 3837 invoked from network); 7 Oct 2002 10:08:23 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 7 Oct 2002 10:08:23 -0000 X-SQ: A X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from majordom by post.thorcom.com with local (Exim 4.10) id 17yUjE-0000bo-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 07 Oct 2002 11:03:08 +0100 Received: from [147.197.200.9] (helo=hestia.herts.ac.uk) by post.thorcom.com with esmtp (Exim 4.10) id 17yUjE-0000bf-00 for rsgb_lf_group@blacksheep.org; Mon, 07 Oct 2002 11:03:08 +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 17yUNN-0007jj-00 for rsgb_lf_group@blacksheep.org; Mon, 07 Oct 2002 10:40:33 +0100 Received: from [147.197.232.252] (helo=rsch-15.herts.ac.uk) by gemini.herts.ac.uk with esmtp (Exim 3.33 #1) id 17yUNC-0005Yk-00 for rsgb_lf_group@blacksheep.org; Mon, 07 Oct 2002 10:40:22 +0100 Message-ID: <5.1.0.14.0.20021007095625.00adb7c8@gemini.herts.ac.uk> X-Sender: mj9ar@gemini.herts.ac.uk X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Mon, 07 Oct 2002 10:38:30 +0100 To: rsgb_lf_group@blacksheep.org From: "James Moritz" In-reply-to: References: MIME-Version: 1.0 X-MailScanner: No Virus detected Subject: LF: Re:RE: LF Revival Content-Type: text/plain; charset=us-ascii; format=flowed X-Spam-Status: No, hits=-0.2 required=5.0tests=DEAR_SOMEBODY,IN_REP_TO,SPAM_PHRASE_01_02version=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Dear Mike Bill, LF Group, At 23:38 06/10/2002 -0500, you wrote: >Most definitely. Scale a 15-meter by 15-meter square vertical loop up for >the 136kc band, and look out. It will work great and you won't start any >fires either. 15m * 185kHz/136kHz =20.4m If we all had 20.4m high antennas, we wouldn't be using kilowatts either! I remain to be convinced about the benefits of loop TX antennas - a lot of any advantage to US Lowfers seems to be due to interpretation of the "part 15" regulations with regard to antennas - if you have the choice of a tuned wire 15m long in total , or a 15m by 15m loop, it is not surprising that the latter is a better bet - it is a much bigger antenna, after all. This choice does not apply on 136k. From a practical point of view, where most peoples' best available antenna is restricted by the number and height of supports that can be used, and the planning permission difficulties they cause, it is much more difficult to keep all that litz wire in the air, rather than have a skinny wire aerial, and keep the litz wrapped round the dustbin! Cheers, Jim Moritz 73 de M0BMU