Return-Path: Received: from mtain-mh12.r1000.mx.aol.com (mtain-mh12.r1000.mx.aol.com [172.29.96.224]) by air-de08.mail.aol.com (v126.13) with ESMTP id MAILINDE081-5ebe4b60b0351af; Wed, 27 Jan 2010 16:29:25 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mh12.r1000.mx.aol.com (Internet Inbound) with ESMTP id 2B8ED380001B4; Wed, 27 Jan 2010 16:29:22 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NaFR9-0005SQ-Ou for rs_out_1@blacksheep.org; Wed, 27 Jan 2010 21:28:31 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NaFR9-0005SG-5W for rsgb_lf_group@blacksheep.org; Wed, 27 Jan 2010 21:28:31 +0000 Received: from mail.gmx.net ([213.165.64.20]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1NaFR6-0006v7-Eq for rsgb_lf_group@blacksheep.org; Wed, 27 Jan 2010 21:28:31 +0000 Received: (qmail invoked by alias); 27 Jan 2010 21:28:17 -0000 Received: from p5DD358AD.dip.t-dialin.net (EHLO Clemens04) [93.211.88.173] by mail.gmx.net (mp018) with SMTP; 27 Jan 2010 22:28:17 +0100 X-Authenticated: #17214767 X-Provags-ID: V01U2FsdGVkX19CdMMyRIlCXE4wAUDtNb29Bm/Bm1YSg1dj8vgLA6 lvWV8VD+DoIRkk Message-ID: <038501ca9f97$a44761a0$0201a8c0@Clemens04> From: "Clemens Paul" To: References: Date: Wed, 27 Jan 2010 22:27:59 +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: 0.48999999999999999,0.47999999999999998 X-Spam-Score: 0.1 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,HTML_TAG_EXIST_TBODY=0.126 Subject: Re: LF: RE: WSPR Reports Content-Type: multipart/alternative; boundary="----=_NextPart_000_0381_01CA9F9F.FAF18870" 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=HTML_40_50,HTML_MESSAGE, HTML_TAG_EXISTS_TBODY 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: 3039ac1d60e04b60b0324bd9 X-AOL-IP: 193.82.116.20 ------=_NextPart_000_0381_01CA9F9F.FAF18870 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable This phenomen,or rather bug,has been reported here by several list mem= bers. I have made the same observations. Reducing the RX BW from e.g. 250Hz to something below 100Hz results in an increase of *reported* SNR of up to around 15dB! I've done some tests with a friend 20km away on 10m and we've found ou= t that the *real* SNR is not improved a bit or in other words an extreme weak wspr signal wh= ich was just below the decoding threshold in 250Hz BW coudn't be decoded with 20Hz BW eit= her. 73 Clemens DL4RAJ ----- Original Message -----=20 From: Andy Talbot To: rsgb_lf_group@blacksheep.org Sent: Wednesday, January 27, 2010 9:44 PM Subject: Re: LF: RE: WSPR Reports All the critical filtering is done in the software, and results in= a 1.46Hz noise bandwidth -=20 which is what the software measures and reports upon. Your observation that a narrower IF bandwidth is interesting. Its= most likely based on the=20 fact that typical signals are corrupted by pulsed non-gaussian noise= which upsets the frequency=20 bin detection process, and upsets sync recovery. Andy www.g4jnt.com This email has been scanned for damaging side-effects by the health= and safety police, is=20 guaranteed to contain no substances hazardous to health, but may contr= ibute to dissolving the=20 nether and polar regions 2010/1/27 Rik Strobbe Andy, maybe the "magic" lies in a narrow filter (either IF or audio). If I switch from a 2.5kHz (SSB) filter to a 270 Hz filter I also= get a significant increase=20 in SNR values reported by WSPR. Unfortunaely it hardly affects the decoding level (minimal SNR nee= ded to get a positive=20 decode), that rises by almost the same amount. 73, Rik ON7YD - OR7T ----------------------------------------------------------------------= ------ Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@black= sheep.org] namens Andy=20 Talbot [andy.g4jnt@googlemail.com] Verzonden: woensdag 27 januari 2010 21:26 Aan: rsgb_lf_group@blacksheep.org Onderwerp: LF: WSPR Reports Has F6CNI managed some sort of magic noise reduction system, or is= it a just a case of being=20 in a very quiet location... These are pretty impressive S/N values 2010-01-27 20:14 G4JNT 0.503875 +13 0 IO90iv +2= 3 0.200 F6CNI JN19qb=20 391 243 2010-01-27 20:08 G4JNT 0.503875 +10 0 IO90iv +2= 3 0.200 F6CNI JN19qb=20 391 243 2010-01-27 20:02 PA0A 0.503900 +15 0 JO33de +37= 5.012 F6CNI JN19qb=20 502 312 2010-01-27 20:00 G4JNT 0.503875 +14 0 IO90iv +2= 3 0.200 F6CNI JN19qb=20 391 243 2010-01-27 19:54 G7NKS 0.503920 -5 0 IO92ub +20= 0.100 F6CNI JN19qb=20 422 262 2010-01-27 19:54 G4JNT 0.503875 +14 0 IO90iv +2= 3 0.200 F6CNI JN19qb=20 391 243 2010-01-27 19:44 G4JNT 0.503875 +10 0 IO90iv +2= 3 0.200 F6CNI JN19qb=20 391 243 2010-01-27 19:40 PA0A 0.503900 +15 0 JO33de +37= 5.012 F6CNI JN19qb=20 502 312 Andy www.g4jnt.com ----------------------------------------------------------------------= -------- Eingehende eMail ist virenfrei. Von AVG =FCberpr=FCft - www.avg.de Version: 9.0.733 / Virendatenbank: 271.1.1/2649 - Ausgabedatum: 01/2= 7/10 14:08:00 ------=_NextPart_000_0381_01CA9F9F.FAF18870 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
This phenomen,or rather bug,has been= reported here=20 by several list members.
I have made the same observations.
Reducing the RX BW from e.g. 250Hz to= something=20 below 100Hz results in
an increase of *reported* SNR of up= to around=20 15dB!
I've done some tests with a friend 20= km away on 10m=20 and we've found out that the *real* SNR
is not improved a bit or in other wor= ds an extreme=20 weak wspr signal which was just below
the decoding threshold in 250Hz BW co= udn't be=20 decoded with 20Hz BW either.
 
73
Clemens
DL4RAJ <= /DIV>
----- Original Message -----
From:=20 Andy Talbot
Sent: Wednesday, January 27,= 2010 9:44=20 PM
Subject: Re: LF: RE: WSPR Rep= orts

All the critical filtering is done in the software, and results= in a=20 1.46Hz noise bandwidth - which is what the software measures and rep= orts=20 upon.
 
Your observation that a narrower IF bandwidth is interesting.&n= bsp; =20 Its most likely based on the fact that typical signals are corrupted= by pulsed=20 non-gaussian noise which upsets the frequency bin detection process,= and=20 upsets sync recovery.
 

Andy
ww= w.g4jnt.com

This email has been=20 scanned for damaging side-effects by the health and safety police,= is=20 guaranteed to contain no substances hazardous to health, but may con= tribute to=20 dissolving the nether and polar regions


2010/1/27 Rik Strobbe <<= A href=3D"mailto:Rik.Strobbe@fys.kuleuven.be">Rik.Strobbe@fys.kule= uven.be>
Andy,<= /FONT>
 
maybe the "magic"= lies in a=20 narrow filter (either IF or audio).
If I switch from a 2.5= kHz (SSB) filter=20 to a 270 Hz filter I also get a significant increase in SNR= values=20 reported by WSPR.
Unfortunaely it hardly= affects the=20 decoding level (minimal SNR needed to get a positive decode), that= rises by=20 almost the same amount.
 
73, Rik  ON7YD -= =20 OR7T
Van: owner-rsgb_lf= _group@blacksheep.org [owner-rsgb_lf_group@blacksheep.= org] namens Andy Talbot [andy.g4jnt@googlemail.com]
V= erzonden: woensdag=20 27 januari 2010 21:26
Aan: rsgb_lf_group@blackshee= p.org
Onderwerp: LF: WSPR=20 Reports

Has F6CNI managed some sort of magic noise reduction system,= or is it a=20 just a case of being in a very quiet location...
These are pretty impressive S/N values
 
 
 2010-01-27 20:14   G4JNT   0.503875   +13   0   IO90iv   +23   0.200   F6CNI   JN19qb   391   243 
 2010-01-27 20:08   G4JNT   0.503875   +10   0   IO90iv   +23   0.200   F6CNI   JN19qb   391   243 
 2010-01-27 20:02   PA0A   0.503900   +15   0   JO33de   +37   5.012   F6CNI   JN19qb   502   312 
 2010-01-27 20:00   G4JNT   0.503875   +14   0   IO90iv   +23   0.200   F6CNI   JN19qb   391   243 
 2010-01-27 19:54   G7NKS   0.503920   -5   0   IO92ub   +20   0.100   F6CNI   JN19qb   422   262 
 2010-01-27 19:54   G4JNT   0.503875   +14   0   IO90iv   +23   0.200   F6CNI   JN19qb   391   243 
 2010-01-27 19:44   G4JNT   0.503875   +10   0   IO90iv   +23   0.200   F6CNI   JN19qb   391   243 
 2010-01-27 19:40   PA0A   0.503900   +15   0   JO33de   +37   5.012   F6CNI   JN19qb   502   312 
 


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