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[195.171.43.25]) by mx.google.com with ESMTP id p2si334681eef.184.2013.07.03.17.23.09 for ; Wed, 03 Jul 2013 17:23:10 -0700 (PDT) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1UuUgY-0001GC-1a for rs_out_1@blacksheep.org; Wed, 03 Jul 2013 22:33:58 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1UuUgX-0001G3-9p for rsgb_lf_group@blacksheep.org; Wed, 03 Jul 2013 22:33:57 +0100 Received: from relay.uni-heidelberg.de ([129.206.100.212]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1UuUgV-0003KQ-H6 for rsgb_lf_group@blacksheep.org; Wed, 03 Jul 2013 22:33:56 +0100 Received: from freitag.iup.uni-heidelberg.de (freitag.iup.uni-heidelberg.de [129.206.29.204]) by relay.uni-heidelberg.de (8.14.1/8.14.1) with ESMTP id r63LXsvV008972 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 3 Jul 2013 23:33:54 +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 r63LXsWg031590 for ; Wed, 3 Jul 2013 23:33:54 +0200 Message-ID: <51D498BD.3050007@iup.uni-heidelberg.de> Date: Wed, 03 Jul 2013 23:33:49 +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: In-Reply-To: X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Wow, thanks. This can lead to a lively discussion :-) I think there are some misunderstandings by VK1OD. He states that Roelof says that: "noise is mainly magnetic". But Roelof means the local noise and not the far field noise, e.g. from thunderstorms. That is the difference! The local noise H fields pass the walls rather than the E fields, in many constellations like urban areas. Furthermore there can be a significant advantage in the obtainable SNR compared to a "big" antenna because that small whip antenna can be lifted easily by several meters above ground, without having a high wind load. A big antenna with a feed point at ground level and a few meters near the house may catch a lot of local noise. [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [129.206.100.212 listed in list.dnswl.org] -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Scan-Signature: 4e3b1488273adbbe9757d6bdd5adf219 Subject: Re: LF: VK1OD's analysis of the MiniWhip antenna Content-Type: text/plain; charset=ISO-8859-1; format=flowed 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 Status: O X-Status: X-Keywords: X-UID: 3115 Wow, thanks. This can lead to a lively discussion :-) I think there are some misunderstandings by VK1OD. He states that Roelof says that: "noise is mainly magnetic". But Roelof means the local noise and not the far field noise, e.g. from thunderstorms. That is the difference! The local noise H fields pass the walls rather than the E fields, in many constellations like urban areas. Furthermore there can be a significant advantage in the obtainable SNR compared to a "big" antenna because that small whip antenna can be lifted easily by several meters above ground, without having a high wind load. A big antenna with a feed point at ground level and a few meters near the house may catch a lot of local noise. For me, here on the institutes roof, the small whip antenna (https://dl.dropboxusercontent.com/u/19882028/MF/LFMFprobe.JPG) achieved MUCH better results than the 70m long wire (https://dl.dropboxusercontent.com/u/19882028/LF/IUP%20Antenne_resize.jpg)... 73, Stefan/DK7FC Am 03.07.2013 01:02, schrieb Dimitrios Tsifakis: > Hello group, > > here is a web page written by Owen, VK1OD with an analysis of how > PA0RDT's Miniwhip antenna works: > > http://vk1od.net/antenna/PA0RDT-MiniWhip/index.htm > > You may find this interesting. > > 73, Dimitris VK1SV >