Return-Path: Received: from mtain-ma09.r1000.mx.aol.com (mtain-ma09.r1000.mx.aol.com [172.29.96.17]) by air-mf03.mail.aol.com (v129.4) with ESMTP id MAILINMF033-8be34bec52dd140; Thu, 13 May 2010 15:28:29 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-ma09.r1000.mx.aol.com (Internet Inbound) with ESMTP id 2895B3800009C; Thu, 13 May 2010 15:28:27 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OCe3y-0002oD-D5 for rs_out_1@blacksheep.org; Thu, 13 May 2010 20:27:18 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OCe3x-0002o4-TR for rsgb_lf_group@blacksheep.org; Thu, 13 May 2010 20:27:17 +0100 Received: from smtp-vbr13.xs4all.nl ([194.109.24.33]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OCe3v-0004Uk-81 for rsgb_lf_group@blacksheep.org; Thu, 13 May 2010 20:27:17 +0100 Received: from pc1 (ndb.demon.nl [82.161.81.65]) by smtp-vbr13.xs4all.nl (8.13.8/8.13.8) with ESMTP id o4DJR9gO042137 for ; Thu, 13 May 2010 21:27:14 +0200 (CEST) (envelope-from roelof@ndb.demon.nl) To: rsgb_lf_group@blacksheep.org References: <003501caf1fd$9d39a0e0$0401a8c0@xphd97xgq27nyf> <4BEBEE46.9040702@iup.uni-heidelberg.de> <4BEC496D.3000300@iup.uni-heidelberg.de> Date: Thu, 13 May 2010 19:27:07 -0000 MIME-Version: 1.0 From: "Roelof Bakker" Message-ID: In-Reply-To: <4BEC496D.3000300@iup.uni-heidelberg.de> User-Agent: Opera Mail/10.53 (Win32) X-Virus-Scanned: by XS4ALL Virus Scanner X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Content-Type: text/plain; charset=iso-8859-15; format=flowed; delsp=yes Subject: Re: VLF: Outdoor test for different places for active E-field antennas for VLF Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G x-aol-sid: 3039ac1d60114bec52db6f81 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) Hello Stefan, Many thanks for sharing your findings. I have done similar tests at 137 kHz and 400 kHz. In a nutshell, it did not pay off to raise the antenna 6 meter ( total height 12 meter) above the semi flat roof of my house, compared to 5 metre high in the garden as the signal to noise ratio did not improve. Unfortunately, I did not monitor the Russian Alpha signals at the time. I did find a 15 dB lower signal level at 11.906 kHz at my city location compared to a a free field location, though. Both antennas were at the same height. I have a few chestnut trees 20 metre away which are full with new leaves and blossom. At 400 kHz they have a screening effect of 1.5 to 2 dB! Maybe you can check the signal to noise issue again when you have a real signal for comparison, to make sure that your assumptions are valid. Enjoy your weekend! 73, Roelof, pa0rdt