Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-me05.r1000.mx.aol.com (Internet Inbound) with ESMTP id B2FED380000A1; Mon, 11 Jul 2011 14:10:17 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QgKuZ-0006hd-I5 for rs_out_1@blacksheep.org; Mon, 11 Jul 2011 19:08:51 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QgKuY-0006hU-Sn for rsgb_lf_group@blacksheep.org; Mon, 11 Jul 2011 19:08:50 +0100 Received: from outbound04.telus.net ([199.185.220.223] helo=defout.telus.net) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1QgKuV-00011I-Ld for rsgb_lf_group@blacksheep.org; Mon, 11 Jul 2011 19:08:50 +0100 Received: from edtncm03 ([199.185.220.221]) by priv-edtnes25.telusplanet.net (InterMail vM.8.01.03.00 201-2260-125-20100507) with ESMTP id <20110711180844.JOUW7242.priv-edtnes25.telusplanet.net@edtncm03> for ; Mon, 11 Jul 2011 12:08:44 -0600 Received: from [192.168.1.115] ([75.157.140.188]) by edtncm03 with bizsmtp id 6i8k1h0074453Jb01i8kcg; Mon, 11 Jul 2011 12:08:44 -0600 X-Telus-Outbound-IP: 75.157.140.188 X-Authority-Analysis: v=1.1 cv=jQecjTLvkVOfO0RXIOi7G8FjOjm8bD+DWsRFYIkvbQI= c=1 sm=2 a=qGV6uSQ7kSsA:10 a=J_qFMZc6TkUA:10 a=LGgl8L9ij00A:10 a=Q9fys5e9bTEA:10 a=w0A1Y-pYAAAA:8 a=Gn9sAD8zR4nowH72hrEA:9 a=PUjeQqilurYA:10 a=VXQHjskrUgMA:10 Message-ID: <4E1B3C2A.4080109@telus.net> Date: Mon, 11 Jul 2011 11:08:42 -0700 From: Scott Tilley User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:5.0) Gecko/20110624 Thunderbird/5.0 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <4E1B0269.2060103@iup.uni-heidelberg.de> In-Reply-To: <4E1B0269.2060103@iup.uni-heidelberg.de> X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,RATWARE_GECKO_BUILD=1.426 Subject: Re: VLF: 3 and 1.3 kHz at VE7TIL Content-Type: text/plain; charset=ISO-8859-15; format=flowed 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=0.9 required=5.0 tests=FROM_ENDS_IN_NUMS 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: 0:2:363191392:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d608d4e1b3c88457a X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hi Stefan What you are seeing is natural. See this paper: http://www.vlf.it/naturalnoisefloor/naturalnoisefloor.htm 73 Scott VE7TIL On 7/11/2011 7:02 AM, Stefan Schäfer wrote: > Hi Scott, VLF, > > Scott, i just took a look on your VLF grabber and saw the sferics are > interestingly (clear!) attenuated in the range of 1.3 and 3 Khz. There > is a sharp limit where the sferics are not visible. Is there a man > made reason or is it due to a natural effect? Most people have strong > QRM/hum on that QRG... > > 73, Stefan/DK7FC > >