Return-Path: Received: (qmail 29446 invoked from network); 7 Jan 2004 20:50:59 -0000 Received: from unknown (HELO ptb-mxscan03.plus.net) (212.159.14.237) by ptb-mailstore02.plus.net with SMTP; 7 Jan 2004 20:50:59 -0000 Received: (qmail 62640 invoked from network); 7 Jan 2004 20:50:59 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from ptb-mxcore03.plus.net (212.159.14.217) by ptb-mxscan03.plus.net with SMTP; 7 Jan 2004 20:50:58 -0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore03.plus.net with esmtp (Exim) id 1AeKdm-000GBK-A2 for dave@picks.force9.co.uk; Wed, 07 Jan 2004 20:50:58 +0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1AeKd6-00076A-4P for rs_out@blacksheep.org; Wed, 07 Jan 2004 20:50:16 +0000 Received: from [212.135.6.12] (helo=smarthost2.mail.uk.easynet.net) by post.thorcom.com with esmtp (Exim 4.14) id 1AeKd5-000761-Mb for rsgb_lf_group@blacksheep.org; Wed, 07 Jan 2004 20:50:15 +0000 Received: from tnt-1-47.easynet.co.uk ([195.40.206.47] helo=erica) by smarthost2.mail.uk.easynet.net with smtp (Exim 4.10) id 1AeKcz-000H0Z-00 for rsgb_lf_group@blacksheep.org; Wed, 07 Jan 2004 20:50:09 +0000 X-Bad-Message-ID: no DNS (erica) Message-ID: <003101c3d561$e1af1e40$2fce28c3@erica> From: "g3ldo" To: rsgb_lf_group@blacksheep.org References: <000201c3d2f3$c4fb5f40$61e4fc3e@l8p8y6> <6.0.1.1.2.20031229161651.027e8660@POP3.freeler.nl> <000001c3d009$acf7a620$c7e47f50@Smisan> <6.0.1.1.2.20040103121138.0280f960@POP3.freeler.nl> <000601c3d2c3$2bd34e70$b733f7c2@johnb5a82ea1a4> <6.0.1.1.2.20040104163146.027efbe0@POP3.freeler.nl> <000201c3d2f3$c4fb5f40$61e4fc3e@l8p8y6> <5.1.0.14.0.20040106090928.03a8c2a0@u0019445.kuleuven.be> Date: Wed, 7 Jan 2004 20:41:27 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: Re: LF: Horizontally polarised radiation Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.60 (1.212-2003-09-23-exp) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.6 required=5.0 tests=CELL_PHONE_BOOST autolearn=no version=2.60 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: rs_out@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SPAMFiltered: yes X-Spam-Rating: 2 Rik, ON4YD said ----------------------------------- It is an "idée fixe" that a horizontal wire must radiate a horizontal polarized EM-wave. A nice example of a mechanical horizontal construction that radiates a vertical polarized signal is the DDRR antenna. So a large horizontal topload close to ground will in most cases improve the antenna efficiency (reduce the loss resistance ... footprint theory) but the radiated signal will be nevertheless mainly vertical polarized. ---------------------------------- Very true. Some years ago I modelled my LF antenna with losses introduced based on measured parameters. My antenna showed a gain of -23dBi. The 3D pattern showed a half doughnut with a -22dBi vertical null. Maximum radiation was indicated at 12 degrees. Polarisation was totally vertical. I then modelled OH1TN's antenna comprising a 500m wire, 28m high. This antenna showed a gain of 16dBi, which was based on average ground - the 'real world' parameters were not known. This antenna showed a broad elevation gain of 16 to 70degrees with no doughnut dip in the centre. In spite of this there was no detectable horizontal polarisation radiation. Judging by signal reports this antenna (and QTH) is exceptionally good as a receiving site. I made a rectangle DDRR antenna for 14MHz for mobile use - it looked like a roof rack. This indicated a small degree of vertical polarisation but this may have been radiating from the vehicle itself. Regards, Peter, G3LDO