Return-Path: Received: from mtain-mc06.r1000.mx.aol.com (mtain-mc06.r1000.mx.aol.com [172.29.96.78]) by air-md09.mail.aol.com (v126.13) with ESMTP id MAILINMD091-8b944b6f5495374; Sun, 07 Feb 2010 19:02:29 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mc06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 15BD438000050; Sun, 7 Feb 2010 19:02:27 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NeH3c-0006br-SF for rs_out_1@blacksheep.org; Mon, 08 Feb 2010 00:00:52 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NeH3c-0006bi-Dy for rsgb_lf_group@blacksheep.org; Mon, 08 Feb 2010 00:00:52 +0000 Received: from mail.gmx.net ([213.165.64.20]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1NeH3a-00059J-5f for rsgb_lf_group@blacksheep.org; Mon, 08 Feb 2010 00:00:52 +0000 Received: (qmail invoked by alias); 08 Feb 2010 00:00:43 -0000 Received: from p5DC4357C.dip.t-dialin.net (EHLO Clemens04) [93.196.53.124] by mail.gmx.net (mp004) with SMTP; 08 Feb 2010 01:00:43 +0100 X-Authenticated: #17214767 X-Provags-ID: V01U2FsdGVkX1+Jd+lkRj6JV9j+30RYUyuJAGEc/eStK0qUOdPlSG A5o0IemmRl7ebr Message-ID: <00a701caa851$c231ee70$0201a8c0@Clemens04> From: "Clemens Clemens" To: References: Date: Mon, 8 Feb 2010 01:00:40 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3598 x-mimeole: Produced By Microsoft MimeOLE V6.00.2900.3350 X-Y-GMX-Trusted: 0 X-FuHaFi: 0.56999999999999995,0.56999999999999995 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: Re: WSPR S/N Tests Content-Type: multipart/alternative; boundary="----=_NextPart_000_00A3_01CAA85A.22308A90" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,HTML_MESSAGE 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: 3039ac1d604e4b6f5493491b X-AOL-IP: 193.82.116.20 ------=_NextPart_000_00A3_01CAA85A.22308A90 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Andy, thanks for confirming that. 73 Clemens DL4RAJ ----- Original Message -----=20 From: Andy Talbot To: rsgb_lf_group@blacksheep.org Cc: jfell@tesco.net Sent: Sunday, February 07, 2010 7:20 PM Subject: LF: WSPR S/N Tests To try to get to grips with the falsely high values of S/N reported= by some stations=20 recently, I made a set of controlled measurements over a direct link= using a range of Rx=20 bandwidths and input signal levels. The results were dramatic. With receive bandwidths less than 300Hz,= the reported S/N=20 increased considerably. It was only possible to use bandwidths in st= eps of 500Hz so=20 100,150,200 etc with the SDR-IQ but these were more than enough to sho= w the effect. Full details can be found in www.g4jnt.com/WSPR_SNR_Test.pdf but th= e results can be=20 summarised as : ------------- Don't use a bandwidth below 300Hz unless you want ar= tificially high SNR=20 reports ----------------------- 300Hz or anything higher that allows the decoding software to see th= e full noise band is OK. Andy www.g4jnt.com ----------------------------------------------------------------------= -------- Eingehende eMail ist virenfrei. Von AVG =FCberpr=FCft - www.avg.de Version: 9.0.733 / Virendatenbank: 271.1.1/2673 - Ausgabedatum: 02/0= 7/10 08:22:00 ------=_NextPart_000_00A3_01CAA85A.22308A90 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Andy,
 
thanks for confirming that.
 
73
Clemens
DL4RAJ
----- Original Message -----
From:=20 Andy Talbot
Sent: Sunday, February 07, 20= 10 7:20=20 PM
Subject: LF: WSPR S/N Tests

To try to get to grips with the falsely high values of  S/= N reported=20 by some stations recently, I made a set of controlled measurements= over a=20 direct link using a range of Rx bandwidths and input signal levels.<= /DIV>
 
The results were dramatic.  With receive bandwidths= less than=20 300Hz, the reported S/N increased considerably.   It was= only=20 possible to use bandwidths in steps of 500Hz so 100,150,200 etc with= the=20 SDR-IQ but these were more than enough to show the effect.
 
Full details can be found in www.g4jnt.com/WSPR_SNR_Test.pdf =20 but the results can be summarised as :
 
-------------   Don't use a bandwidth below 300Hz unl= ess you=20 want artificially high SNR reports  =20  -----------------------
 
300Hz or anything higher that allows the decoding software to= see the=20 full noise band is OK.


Eingehende eMail ist virenfrei.
Von AVG =FCberpr=FCft= - www.avg.de=20
Version: 9.0.733 / Virendatenbank: 271.1.1/2673 - Ausgabedatum:= 02/07/10=20 08:22:00
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