Return-Path: Received: (qmail 17197 invoked from network); 1 Oct 2001 12:22:00 -0000 Content-Transfer-Encoding: 8bit Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 1 Oct 2001 12:22:00 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 15597 invoked from network); 1 Oct 2001 12:21:41 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 1 Oct 2001 12:21:41 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 15o20P-0002P3-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 01 Oct 2001 13:17:05 +0100 Received: from public2.thorcom.com ([212.172.148.20] ident=root) by post.thorcom.com with esmtp (Exim 3.16 #2) id 15o20O-0002Om-00 for rsgb_lf_group@blacksheep.org; Mon, 01 Oct 2001 13:17:04 +0100 Received: from mail.cc.kuleuven.ac.be ([134.58.10.6]) by public2.thorcom.com with esmtp (Exim 3.02 #1) id 15o1Xj-0008DP-00 for rsgb_lf_group@blacksheep.org; Mon, 01 Oct 2001 12:47:28 +0100 Received: from LCBD15.fys.kuleuven.ac.be (LCBD15.fys.kuleuven.ac.be [134.58.80.15]) by mail.cc.kuleuven.ac.be (8.9.3/8.9.0) with SMTP id OAA159740 for ; Mon, 1 Oct 2001 14:08:28 +0200 Message-ID: <3.0.1.16.20011001130655.30f79622@mail.cc.kuleuven.ac.be> X-Sender: pb623250@mail.cc.kuleuven.ac.be X-Mailer: Windows Eudora Pro Version 3.0.1 (16) Date: Mon, 01 Oct 2001 13:06:55 To: rsgb_lf_group@blacksheep.org From: "Rik Strobbe" Subject: Re: LF: Re: 73KHz beacon In-reply-to: <3BB85281.93CDD0D8@usa.net> References: <3.0.1.16.20011001084908.2af76e6c@mail.cc.kuleuven.ac.be> <3.0.1.16.20011001105044.2d67661a@mail.cc.kuleuven.ac.be> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: >Rik, thanks for the explanations. >I would have never imagined that the gain provided by having a radiation >diagram 'squeezed' in the vertical plane could more than compensate for >the losses caused by the very short dimensions (compared to the wavelength) >of the antenna. Today I learnt a new one. TNX. Hi Alberto, If an short vertical monopole is placed over perfect ground and brought to resonance with a perfect loadingcoil there are no losses, so its performance will be independent of its length. It looks a bit strange at first sight but in the perfect world there are no losses and so every mW you put into the antenna will be radiated regardless wether the antenna is 1m or 100m high. Unfortunately there is no perfect ground and no lossless loading coil so in practice (on 136kHz) a longer antenna will outperform a shorter and the one who can put a lambda/2 dipole at lambda/4 height will have the super-antenna (but this antenna just doesn't fit in my back yard). 73, Rik ON7YD