Delivered-To: daveyxm@virginmedia.com Received: by 10.50.1.100 with SMTP id 4csp3155igl; Wed, 10 Jul 2013 16:29:49 -0700 (PDT) X-Received: by 10.112.5.199 with SMTP id u7mr16100991lbu.67.1373498988504; Wed, 10 Jul 2013 16:29:48 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com. [195.171.43.25]) by mx.google.com with ESMTP id x6si13038451lbq.78.2013.07.10.16.29.47 for ; Wed, 10 Jul 2013 16:29:48 -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 1Ux3oQ-0008JZ-G9 for rs_out_1@blacksheep.org; Thu, 11 Jul 2013 00:28:42 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Ux3oQ-0008JQ-3P for rsgb_lf_group@blacksheep.org; Thu, 11 Jul 2013 00:28:42 +0100 Received: from smtpout5.wanadoo.co.uk ([80.12.242.80] helo=smtpout.wanadoo.co.uk) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1Ux3oO-0007JN-6u for rsgb_lf_group@blacksheep.org; Thu, 11 Jul 2013 00:28:40 +0100 Received: from AGB ([2.31.68.175]) by mwinf5d62 with ME id ynUf1l0043mtKD603nUfPq; Thu, 11 Jul 2013 01:28:39 +0200 Message-ID: From: "Graham" To: References: <13fc83ae7fa.marcocadeddu@tin.it> <51DDE4F2.8010907@iup.uni-heidelberg.de> In-Reply-To: <51DDE4F2.8010907@iup.uni-heidelberg.de> Date: Thu, 11 Jul 2013 00:28:39 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 X-Spam-Score: 0.0 (/) 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: I thought that was the general description ... ' E Probe' as in volts ? G.. From: "Stefan Schäfer" Sent: Wednesday, July 10, 2013 11:49 PM To: Subject: Re: R: Re: Fwd: Re: LF: VK1OD's analysis of the MiniWhip antenna [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [80.12.242.80 listed in list.dnswl.org] X-Scan-Signature: 7001055fa59a9c23b9831ea6d317a074 Subject: Re: R: Re: Fwd: Re: LF: VK1OD's analysis of the MiniWhip antenna Content-Type: text/plain; format=flowed; charset="utf-8"; reply-type=response Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=MISSING_OUTLOOK_NAME 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: 3457 I thought that was the general description ... ' E Probe' as in volts ? G.. -------------------------------------------------- From: "Stefan Schäfer" Sent: Wednesday, July 10, 2013 11:49 PM To: Subject: Re: R: Re: Fwd: Re: LF: VK1OD's analysis of the MiniWhip antenna > Well, i find it not strange at all that it works. The discussed antennas > are just impedance converters. The input impedance is in the range of 1 > MOhm and the output impdeance is lower. > Did you never see a (small) voltage on an oscilloscope when a simple probe > is connected, while transmitting on LF/MF? The scope has an input > impedance of 1 MOhm (and some pF). Now take an oscilloscope with battery > supply, connect the probe and put it into a Helium balloon and let the > probe hang down. Then let the stuff rise to near your TX antenna and see > the signal on the scope. It would also work without a ground! > (Then see all the stuff crashing down in your neighbours swimming pool). > > Compared to the scope, the discussed antennas just have to be more > sensitive, minimizing all that noise stuff, while my scope starts at > 5mV/div. And 1 mV signal level would be a BIG signal for the RX! :-) > > 73, Stefan/DK7FC > > >