Return-Path: Received: from mtain-df09.r1000.mx.aol.com (mtain-df09.r1000.mx.aol.com [172.29.64.221]) by air-dd09.mail.aol.com (v129.4) with ESMTP id MAILINDD093-865f4d2dd1d2285; Wed, 12 Jan 2011 11:07:46 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-df09.r1000.mx.aol.com (Internet Inbound) with ESMTP id C71C238000393; Wed, 12 Jan 2011 11:07:42 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Pd3Dr-0008KG-2M for rs_out_1@blacksheep.org; Wed, 12 Jan 2011 16:06:55 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Pd3Dq-0008K7-Ms for rsgb_lf_group@blacksheep.org; Wed, 12 Jan 2011 16:06:54 +0000 Received: from relay.uni-heidelberg.de ([129.206.100.212]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Pd3Dp-0008WG-0M for rsgb_lf_group@blacksheep.org; Wed, 12 Jan 2011 16:06:54 +0000 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 p0CG6pL2015010 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 12 Jan 2011 17:06:51 +0100 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 p0CG6oVp018895 for ; Wed, 12 Jan 2011 17:06:50 +0100 Message-ID: <4D2DD0CA.1090405@iup.uni-heidelberg.de> Date: Wed, 12 Jan 2011 17:03:22 +0100 From: =?UTF-8?B?U3RlZmFuIFNjaMOkZmVy?= 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: <1294845503.2424.23.camel@gerhard-desktop> In-Reply-To: <1294845503.2424.23.camel@gerhard-desktop> X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,RATWARE_GECKO_BUILD=1.426 Subject: Re: LF: "Noisy" antenna on VLF Content-Type: text/plain; charset=UTF-8; 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 x-aol-global-disposition: G x-aol-sid: 3039ac1d40dd4d2dd1ce3916 X-AOL-IP: 195.171.43.25 X-Mailer: Unknown (No Version) Hi Gerhard, Am 12.01.2011 16:18, schrieb Gerhard Hickl: > When you walk from one to the other, the sound would > nearly disappear right in the middle but getting louder as you approach > the other open end. > > So if anybody has an explanation for this or has witnessed a similar > thing, please let me (us) know. > Well, i think its acoustic interference. At some locations, the different audio sources are compensating each other. Since the phase of these two signals does noch change, you should get minima and maxima. I observed this in my car with the 700 Hz CW sidetone as well. On 8970 Hz the (audio) wavelength is just 4 cm. Hmm, do these maxima and minima just appear in the center on the Y or can you find them on other places as well, maybe at reduced strength? 73, Stefan/DK7FC