Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-me05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 6C60A38000085; Sat, 15 Oct 2011 12:54:57 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RF7Uw-0000E1-85 for rs_out_1@blacksheep.org; Sat, 15 Oct 2011 17:54:10 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RF7Uv-0000Dr-Nr for rsgb_lf_group@blacksheep.org; Sat, 15 Oct 2011 17:54:09 +0100 Received: from relay2.uni-heidelberg.de ([129.206.210.211]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RF7Uu-0008Vk-84 for rsgb_lf_group@blacksheep.org; Sat, 15 Oct 2011 17:54:09 +0100 Received: from freitag.iup.uni-heidelberg.de (freitag.iup.uni-heidelberg.de [129.206.29.204]) by relay2.uni-heidelberg.de (8.13.8/8.13.8) with ESMTP id p9FGs6Aq010620 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Sat, 15 Oct 2011 18:54:07 +0200 Received: from [129.206.22.206] (pc206.iup.uni-heidelberg.de [129.206.22.206]) by freitag.iup.uni-heidelberg.de (8.12.11.20060308/8.11.2) with ESMTP id p9FGs6Kq017509 for ; Sat, 15 Oct 2011 18:54:06 +0200 Message-ID: <4E99BA7D.2000706@iup.uni-heidelberg.de> Date: Sat, 15 Oct 2011 18:53:17 +0200 From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <4E956D89.6080102@iup.uni-heidelberg.de> <4E97032B.30905@iup.uni-heidelberg.de> <4E997913.8090104@iup.uni-heidelberg.de> <9D54B5BB-28A1-409E-8D5E-BB6DDF91B856@numeo.fr> In-Reply-To: <9D54B5BB-28A1-409E-8D5E-BB6DDF91B856@numeo.fr> X-MIME-Autoconverted: from 8bit to quoted-printable by relay2.uni-heidelberg.de id p9FGs6Aq010620 X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,RATWARE_GECKO_BUILD=1.426 Subject: Re: LF: noise on VK and earth dipole tests Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable 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-SCOLL-SCORE: 0:2:428988928:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d608d4e99bae166ba X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hi John, Yes, the more the better. If it is just one rod and the overall losses would be 450 Ohm, i expect=20 a high ground conductivity which would be worse for an earth antenna...=20 Maybe the elevated wire in the forest is the best (and long lasting)=20 antenna system for /p. Then it must be a closed loop (and Scott and=20 others use) or a looong earth antenna or just a full size dipole, lossy=20 but full size :-) Some dry old and tall trees would be excellent, even=20 as an insulator ;-) 73, Stefan Am 15.10.2011 18:43, schrieb John Rabson: > On 15 Oct 2011, at 14:14CEST, Stefan Sch=E4fer wrote: > > =20 >> Hello Dimitris, >> >> I think the 450 Ohm you get is mostly caused by the earth electrode re= sistance. So if you spend e.g. 2 instead of one earth rod, maybe you can = get a 3 dB improvement? >> =20 > The more the better up to 6 or 7 rods. > > From cave radio tests we find that the earth rods need to be spaced b= y 2 or more times their depth. > > John F5VLF > > > > =20