Return-Path: Received: (qmail 22418 invoked from network); 20 May 2002 15:07:52 -0000 Content-Transfer-Encoding: 8bit X-Priority: 3 Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by exhibition.plus.net with SMTP; 20 May 2002 15:07:52 -0000 X-MSMail-Priority: Normal Received: (qmail 10329 invoked from network); 20 May 2002 15:07:32 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from unknown (HELO post.thorcom.com) (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 20 May 2002 15:07:32 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 179oem-0002wr-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 20 May 2002 16:01:04 +0100 Received: from astral.infomsk.ru ([212.164.44.2] helo=astral.omskcity.com) by post.thorcom.com with esmtp (Exim 3.33 #2) id 179oeX-0002va-00 for rsgb_lf_group@blacksheep.org; Mon, 20 May 2002 16:00:52 +0100 Received: from fitec.omskcity.com (mu07.dialup2.infomsk.ru [212.164.44.119]) by astral.omskcity.com (8.9.3/8.9.3) with SMTP id VAA3ce90ef442e7 for ; Mon, 20 May 2002 21:57:56 +0700 (OSS) Date: Mon, 20 May 2002 22:38:26 +0000 (GMT) From: "Alexander S. Yurkov" To: rsgb_lf_group@blacksheep.org Subject: Re: LF: more acurate formula for ground loss In-reply-to: <20020520125514.34500B6D7@xmxpita.excite.com> Message-ID: 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: Hi John and Group! On Mon, 20 May 2002, john sexton wrote: > Hi Sasha, > Putting in the same antenna details as before, > the new formula gives 38 ohms, still too low by a factor of over 2, > but much better than with the first formula. I just compare the formula to NEC-2 (Sommerfeld ground) modeling and get such a result: H=20m, l=100m, s=1mSm/m h Rin Rrad Rg Rg formula/NEC m NEC NEC formula 0.5 6.67 0.13 6.54 7.47 1.14 1 4.97 0.12 4.85 5.43 1.12 2 3.31 0.11 3.20 3.52 1.10 3 2.42 0.10 2.32 2.51 1.08 4 1.83 0.08 1.75 1.87 1.07 It seems differences is due to not enought segmentation in modeling (1 meter of segment length). I can't do better segmentation because of my computer is not so good... 73 de RA9MB/Alex http://www.qsl.net/ra9mb