Return-Path: Received: (qmail 2340 invoked from network); 27 Jul 1999 19:43:25 +0100 Received: from magnus.plus.net.uk (HELO magnus.force9.net) (195.166.128.27) by guiness.force9.net with SMTP; 27 Jul 1999 19:43:25 +0100 Received: (qmail 20494 invoked from network); 27 Jul 1999 18:46:07 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by magnus.plus.net.uk with SMTP; 27 Jul 1999 18:46:07 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 119Bua-0002uX-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 27 Jul 1999 19:25:12 +0100 Received: from irwell.zetnet.co.uk ([194.247.47.48] ident=root) by post.thorcom.com with esmtp (Exim 3.02 #1) id 119BuX-0002uS-00 for rsgb_lf_group@blacksheep.org; Tue, 27 Jul 1999 19:25:11 +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 TAA18772 for ; Tue, 27 Jul 1999 19:25:04 +0100 X-ZSender: g3ldo@zetnet.co.uk Message-ID: <1999072719350468199@zetnet.co.uk> Date: Tue, 27 Jul 1999 19:35:04 +0100 To: rsgb_lf_group@blacksheep.org From: "Peter Dodd" X-Mailer: ZIMACS Version 1.20c 10000836 Subject: Re: LF: Who uses EZNEC Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org Sender: Content-type: text/plain; charset=windows-1252; format=flowed MIME-Version: 1.0 Content-transfer-encoding: 8bit from "Soegiono, Gamal" > does anyone of you have experience with EZNEC modelling software? Yes, I do > As far as I know, this is the only software (except for the original but > cumbersome NEC) capable of modelling the ground influence on > antenna feedpoint Impedance as well as on far field diagram AND > incorporating the conductor conductivity. > Most other programs account for ground influence on far field diagram, > but not on feed impedance, conductor losses are omitted. EZNEC does most of these things quite well, see page 6.9 of 'The LF Experimenter's Source Book' on Computer Modelling of LF Antennas > It might be worthwhile to simulate antenna arrangements with EZNEC, > using an elevated Radial System. Radials need not have resonant > length, but might be "lengthened" by a radial loading coil in addition > to the vertical radiator's loading coil. EZNEC cannot model horizontal wires that are closer than .02 wavelengths from the ground so modelling elevated radials could present a difficulty. As elevated radials are impractical for most of us there seem little point of modelling them. EZNEC is also useful for modelling the actual radiated power from the antenna and was used in the first round of discussions on 'ERP' (about 14 months ago). The results correlated well with measured signal strengths. I first started using K6STI's MN in 1989, which was described in the first edition of the Antenna Experimenter's Guide. I then moved to ELNEC, and finally EZNEC, which was described in the second edition of the Antenna Experimenter's Guide. In fact I felt so confident of modelling LF antennas using EZNEC that I gave a presentation at the LF workshop of the LF Convention last October. I also modelled many of the LF group's antennas and used them for material at the HF Convention. 'The LF Experimenter's Source Book' and 'The Antenna Experimenter's Guide' are available from the RSGB bookshop. -- Regards, Peter, G3LDO