Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-da01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 7F8D9380000A4; Mon, 18 Mar 2013 10:08:17 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1UHair-0004Za-3h for rs_out_1@blacksheep.org; Mon, 18 Mar 2013 14:07:33 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1UHaiq-0004ZN-NX for rsgb_lf_group@blacksheep.org; Mon, 18 Mar 2013 14:07:32 +0000 Received: from smtp-vbr13.xs4all.nl ([194.109.24.33]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1UHaio-0001hC-Mj for rsgb_lf_group@blacksheep.org; Mon, 18 Mar 2013 14:07:31 +0000 Received: from pc-roelof (ndb.demon.nl [82.161.81.65]) by smtp-vbr13.xs4all.nl (8.13.8/8.13.8) with ESMTP id r2IE71Y9050189 for ; Mon, 18 Mar 2013 15:07:10 +0100 (CET) (envelope-from roelof@ndb.demon.nl) To: rsgb_lf_group@blacksheep.org References: <3309.377f234c.3e76743b@aol.com> Date: Mon, 18 Mar 2013 15:07:01 +0100 MIME-Version: 1.0 From: "Roelof Bakker" Message-ID: In-Reply-To: User-Agent: Opera Mail/12.14 (Win32) X-Virus-Scanned: by XS4ALL Virus Scanner X-Spam-Score: 1.6 (+) 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: Hello all, On the WSPR website, http://physics.princeton.edu/pulsar/K1JT/wspr.html [...] Content analysis details: (1.6 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [194.109.24.33 listed in list.dnswl.org] 1.6 SUBJ_ALL_CAPS Subject is all capitals X-Scan-Signature: 086f3faad0220c9ae57a7913e711a86d Content-Type: text/plain; charset=iso-8859-15; format=flowed; delsp=yes Subject: LF: WSPR -2 SNR 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=0.6 required=5.0 tests=SUBJ_ALL_CAPS 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: 3039ac1d404951471fd169c6 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hello all, On the WSPR website, http://physics.princeton.edu/pulsar/K1JT/wspr.html I find this statement: >>> The program can decode signals with S/N as low as -28 dB in a 2500 Hz >>> bandwidth. <<< I have been looking at decodes on WSPR Spots http://wsprnet.org/olddb and it appears that on bands from 160 m and up a SNR smaller than -25 dB is a bit rare. On 630 m these low level decodes are found more often, though decodes with an SNR of -30 are rare. In the nigh of Saturday to Sunday, I had 14 decodes from WG2XJM. Two of these showed a SNR of -33 dB. I have never seen such a low SNR before and a search through the WSPR Spots database showed a decode from a French listener of WG2XJM with an SNR of -31, which is the lowest SNR I could find. As far as I know the bandwidth of the WSPR decoder is set to 200 Hz, so as long as the receiver bandwidth is larger than 200 Hz, decoding should not be effected. My receiver bandwidth is 540 Hz. So, has anyone an idea what is the cause of these low level WSPR decodes. Best regards, Roelof Bakker, pa0rdrt