Return-Path: Received: (qmail 8637 invoked from network); 19 Sep 2002 21:03:23 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 19 Sep 2002 21:03:23 -0000 Received: (qmail 26646 invoked from network); 19 Sep 2002 21:03:08 -0000 Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 19 Sep 2002 21:03:08 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 17s8RA-0006yo-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 19 Sep 2002 22:02:12 +0100 Received: from [195.223.232.51] (helo=netregister.it) by post.thorcom.com with esmtp (Exim 4.10) id 17s8RA-0006ye-00 for rsgb_lf_group@blacksheep.org; Thu, 19 Sep 2002 22:02:12 +0100 Received: from ik2dedlibero (brescia29.phoenix.it [213.82.97.93]) by netregister.it (8.11.4/8.11.4) with SMTP id g8JL2AE01661 for ; Thu, 19 Sep 2002 23:02:10 +0200 Message-ID: <001701c24cc5$28f972e0$5d6152d5@it> From: "Giulio Scaroni" To: rsgb_lf_group@blacksheep.org References: Date: Mon, 26 Aug 2002 07:53:01 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2919.6600 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: Re: LF: IK2DED beacon and E field probe. Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=2.0 required=5.0tests=DOUBLE_CAPSWORD,DATE_IN_PAST_96_XXversion=2.31 X-Spam-Level: ** Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Hi Alex and all, soon i'll measure exactly the antenna current, but one things that appear in this discussion, is that the antenna work very well, it is only a single wire 60 meters long about 1 meters far at the top of the tower, and about 25 meters far at the base. I have read that wire near a tower has many losses, but this seems to confirm the opposite, also the tower that i use in winter in Mantova have the same wire antenna, little bit longer, and with only 100 W my signal is perfectly audible in UK... So, may be that the big tower act like a big additional vertical capacitance to increase signal output?? I don't know, but shure the sistem work well!! I'm listening at 136.100 now (21 Z) and i see a very weak signal/line at the frequency, may will be Vlad?? 73 de Giulio IK2DED. > Hi, David and Group. > Your conclusion may be right. But I say "if antenna curent is 1 A..." and > so on. Large resistance should decrease antenna curent and ERP should be > much lower. This is why one need measure antenna curent to estimate ERP. > Output TX power is not adeqate info. > > Also, it is worth to take into consideration Giulio's relatively high > antenna (60 m!!!) Whithout top load this yeld 30 meters of effective > height. If there is very large top load then ERP should be 4 times grater! > If antenna height is 10 m (for example) then ERP is 9 times lower... > > ERP is mainly determed by antenna current and efffective height. If this > is known then it is very simple to estimate radiated power. Certanly this > is very aproximative estimation. But something is better then nothing :-) > > > 73 de RA9MB/Alex > http://www.qsl.net/ra9mb > > >