Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dh05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 1715C38000219; Mon, 18 Mar 2013 13:26:02 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1UHdTz-0005IS-Tw for rs_out_1@blacksheep.org; Mon, 18 Mar 2013 17:04:23 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1UHdTz-0005IJ-Cz for rsgb_lf_group@blacksheep.org; Mon, 18 Mar 2013 17:04:23 +0000 Received: from qmta02.westchester.pa.mail.comcast.net ([76.96.62.24]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1UHdTx-0002TD-2s for rsgb_lf_group@blacksheep.org; Mon, 18 Mar 2013 17:04:22 +0000 Received: from omta15.westchester.pa.mail.comcast.net ([76.96.62.87]) by qmta02.westchester.pa.mail.comcast.net with comcast id Cz6w1l0041swQuc5153zMh; Mon, 18 Mar 2013 17:03:59 +0000 Received: from DELL4 ([71.234.119.9]) by omta15.westchester.pa.mail.comcast.net with comcast id D53y1l00j0CFS1j3b53zhv; Mon, 18 Mar 2013 17:03:59 +0000 Message-ID: <005101ce23fa$952aa840$6d01a8c0@DELL4> From: To: References: <3309.377f234c.3e76743b@aol.com> Date: Mon, 18 Mar 2013 13:03:58 -0400 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20121106; t=1363626239; bh=I4RKkZDHA+dydx0UDPIfMRaTNadYjk8Z/84JMmoH7ok=; h=Received:Received:Message-ID:From:To:Subject:Date:MIME-Version: Content-Type; b=JPXdCSChB6DF0jISdqHqu7AOYoggSaL3/H5I/vIUJ9+fFlEE3+Z+vk4z0loDJsxE/ MeDMzlOttiFm5IN7JTOndRVNlr7XZ6/1ilUeZqNFlrK1j3hnwAkgTMehKwuIfSAkaD /S/b9YHKrnVz+7QWQq03KFeS2c4Q9HEHXnAItWioNG8GebJQ9IdWC7s3kXhdLf7In/ ulP6kdxxx3lCo9FnjIgdjEp+6ia74WUNC4TTkOV+gh534ZqUGVs4F13cAvwWDun6fG b26I1/zBtsAvZ/XmVOaGDRP/ZUYa3qIPB/LuBio88OfSZz7ecz2oPYkYj9+IIVG5+n I6IJsRRZmGidw== X-Spam-Score: 0.3 (/) 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: >My receiver bandwidth is 540 Hz. It has been shown in the past that a receiver bandwidth significatly less than 2500 Hz artificially inflates the reported WSPR s/n. Jay W1VD WD2XNS WE2XGR/2 [...] Content analysis details: (0.3 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [76.96.62.24 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (jrusgrove[at]comcast.net) -0.0 SPF_PASS SPF: sender matches SPF record -2.5 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid 2.8 AXB_XMAILER_MIMEOLE_OL_4379D AXB_XMAILER_MIMEOLE_OL_4379D X-Scan-Signature: 4b5b5ebe37a4c4f430f59bc35c1947b0 Subject: LF: Re: WSPR -2 SNR Content-Type: text/plain; format=flowed; charset="iso-8859-15"; reply-type=response 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=0.3 required=5.0 tests=NO_REAL_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 x-aol-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mtain-dh05.r1000.mx.aol.com ; domain : comcast.net DKIM : fail x-aol-sid: 3039ac1d411951474e2a7645 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none >My receiver bandwidth is 540 Hz. It has been shown in the past that a receiver bandwidth significatly less than 2500 Hz artificially inflates the reported WSPR s/n. Jay W1VD WD2XNS WE2XGR/2 ----- Original Message ----- From: "Roelof Bakker" To: Sent: Monday, March 18, 2013 10:07 AM Subject: LF: WSPR -2 SNR > 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 >