Return-Path: Received: (qmail 21869 invoked from network); 17 Sep 1999 22:32:41 +0100 Received: from magnet.plus.net.uk (HELO magnet.force9.net) (195.166.128.26) by guiness.force9.net with SMTP; 17 Sep 1999 22:32:41 +0100 Received: (qmail 17256 invoked from network); 17 Sep 1999 21:37:01 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by magnet.plus.net.uk with SMTP; 17 Sep 1999 21:37:01 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 11S5VB-0003h9-00 for rsgb_lf_group-outgoing@blacksheep.org; Fri, 17 Sep 1999 22:25:05 +0100 Received: from irwell.zetnet.co.uk ([194.247.47.48] ident=root) by post.thorcom.com with esmtp (Exim 3.02 #1) id 11S5VA-0003h4-00 for rsgb_lf_group@blacksheep.org; Fri, 17 Sep 1999 22:25:04 +0100 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from central.zetnet.co.uk (central.zetnet.co.uk [194.247.47.20]) by irwell.zetnet.co.uk (8.9.3/8.9.3/Debian/GNU) with SMTP id WAA22393 for ; Fri, 17 Sep 1999 22:24:59 +0100 X-ZSender: g3ldo@zetnet.co.uk Message-ID: <1999091700002468199@zetnet.co.uk> Date: Fri, 17 Sep 1999 00:00:24 +0100 To: rsgb_lf_group@blacksheep.org From: "Peter Dodd" X-Mailer: ZIMACS Version 1.20c 10000836 Subject: LF: Re: EZNEC Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Content-type: text/plain; charset=windows-1252; format=flowed MIME-Version: 1.0 Content-transfer-encoding: 8bit EZNEC modelling software is capable of modelling the ground influence on antenna feedpoint Impedance and conductor conductivity. By comparing a model with zero conductor resistance and perfect ground with a real world model it can estimate efficiency. From this actual radiated power from the antenna can be determined and was used in the first round of discussions on 'ERP' (about 16 months ago). The results correlated well with measured signal strengths. see page 6.9 of 'The LF Experimenter's Source Book' on Computer Modelling of LF Antennas The best efficiency I was able to get from my antenna was about 400mW radiated (erp?) from a transmitter power of 300W, about 0.13% efficient. Regards, Peter, G3LDO