Return-Path: Received: from mtain-dc04.r1000.mx.aol.com (mtain-dc04.r1000.mx.aol.com [172.29.64.132]) by air-de06.mail.aol.com (v126.13) with ESMTP id MAILINDE063-5eb84b60b56f3e3; Wed, 27 Jan 2010 16:51:43 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-dc04.r1000.mx.aol.com (Internet Inbound) with ESMTP id A4A6D38000157; Wed, 27 Jan 2010 16:51:40 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NaFmp-0005xt-8h for rs_out_1@blacksheep.org; Wed, 27 Jan 2010 21:50:55 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NaFmo-0005xj-KJ for rsgb_lf_group@blacksheep.org; Wed, 27 Jan 2010 21:50:54 +0000 Received: from mail-fx0-f219.google.com ([209.85.220.219]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NaFmm-0007E1-EC for rsgb_lf_group@blacksheep.org; Wed, 27 Jan 2010 21:50:54 +0000 Received: by fxm19 with SMTP id 19so11915fxm.29 for ; Wed, 27 Jan 2010 13:50:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=oUk7hfzM+DcG7jnPdw9XimND3rgLXLw0bEtI7pjSg1o=; b=mXABTzy0ZRNjaJ9m7HkgoE7no+njaYp8g/KattZ0eq+W0Z5et9eRzzK9OQQfGSCBtM 33lq73KtdsVnoZYKngt8iIQ1Cx8BvfZMZ1E87ns6WYwYWbxN52f5gk2qin8h3Z4hm9mI qtJTJpYqs9SS39J3AuNA1VP3kJxxRFhoNWKfw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=QLRg5v0L/I10SjjkWyy9Gic3hk3xkFi9pMriwJTJTKaLFlcDFELSyR/B7vbYnT9ESK v8EhgKyOB5ExgUY+5yN+oC/XxpLUxWAMP5GeQ2s+NYY9aDfvvYDvmnkkotyNDV/HFygd eFzH752pnmnJRDL8tVheTWIlwSwhpkgZ9bNgI= MIME-Version: 1.0 Received: by 10.239.193.136 with SMTP id j8mr1170593hbi.105.1264629046706; Wed, 27 Jan 2010 13:50:46 -0800 (PST) In-Reply-To: <038501ca9f97$a44761a0$0201a8c0@Clemens04> References: <038501ca9f97$a44761a0$0201a8c0@Clemens04> Date: Wed, 27 Jan 2010 21:50:46 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) 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=001485f631121a0351047e2c655b 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: 3039ac1d40844b60b56c2824 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --001485f631121a0351047e2c655b Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Yes, as Paul suggests, it does look as if AGC is the culprit. Narrowing the Rx bandwidth right down to 7Hz won't make any difference to decoding ability provided there is no AGC pumping from out of (WSPR band) signals. (But any bandwidth selected below 7Hz will then knock out tone energy in= the two outside ones). Andy www.g4jnt.com 2010/1/27 Clemens Paul > This phenomen,or rather bug,has been reported here by several list > members. > 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 out > that the *real* SNR > is not improved a bit or in other words an extreme weak wspr signal whic= h > was just below > the decoding threshold in 250Hz BW coudn't be decoded with 20Hz BW eithe= r. > > 73 > Clemens > DL4RAJ > > ----- Original Message ----- > *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 1.4= 6Hz > noise bandwidth - which is what the software measures and reports upon. > > Your observation that a narrower IF bandwidth is interesting. Its most > likely based on the fact that typical signals are corrupted by pulsed > non-gaussian noise which upsets the frequency 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 guaranteed to contain no substances hazardous to healt= h, > but may contribute to dissolving the 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 in SNR values reported by WSPR. >> Unfortunaely it hardly affects the decoding level (minimal SNR needed= to >> get a positive decode), that rises by almost the same amount. >> >> 73, Rik ON7YD - OR7T >> ------------------------------ >> *Van:* owner-rsgb_lf_group@blacksheep.org [ >> owner-rsgb_lf_group@blacksheep.org] namens Andy 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 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 42= 2 >> 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 >> >> >> 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: 01/27/10 > 14:08:00 > > --001485f631121a0351047e2c655b Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Yes, as Paul suggests, it does look as if AGC is the culprit.=A0=A0= Narrowing the Rx bandwidth right down to 7Hz won't make any differenc= e to decoding ability provided there is no AGC pumping from out of (WSPR= band) signals.=A0=A0=A0
=A0
(But any bandwidth selected below 7Hz will then knock out tone energy= in the two outside ones).
2010/1/27 Clemens Paul <cpaul@gmx.net>
This phenomen,or rather bug,has been= reported here by several list members.
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 frien= d 20km away on 10m and we've found out that the *real* SNR
is not improved a bit or in other wor= ds an extreme weak wspr signal which was just below
the decoding threshold in 250Hz BW co= udn't be decoded with 20Hz BW either.
=A0
73
Clemens
DL4RAJ=A0
----- Original Message -----
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 - which is what the software measures and reports= upon.
=A0
Your observation that a narrower IF bandwidth is interesting.=A0=A0= Its most likely based on the fact that typical signals are corrupted by= pulsed non-gaussian noise which upsets the frequency bin detection proces= s, and upsets sync recovery.
=A0

Andy
www.g4jnt.com

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


2010/1/27 Rik Strobbe <Rik.Strobbe= @fys.kuleuven.be>
Andy,<= /font>
=A0
maybe=A0the "magic&= quot; lies in a narrow filter (either IF or audio).
If I switch from a 2.5kH= z (SSB) filter to a 270 Hz filter I also get a=A0significant increase in= SNR values reported by WSPR.
Unfortunaely it hardly= affects the decoding level (minimal SNR needed to get a positive decode),= that rises by almost the same amount.
=A0
73, Rik=A0 ON7YD - OR7T<= /font>
Van: owner-rsgb_lf_group@blacksheep.= org [owner-rsgb_lf_group@blacksheep.org] namens Andy Talbot [andy.g4jnt@googlem= ail.com]
Verzonden: woensdag 27 januari 2010 21:26
Aan: rsgb_lf_group@blac= ksheep.org
Onderwerp: LF: WSPR Reports

Has F6CNI managed some sort of magic noise reduction system, or is it= a just a case of being in a very quiet location...
These are pretty impressive S/N values
=A0
=A0
=A02010-01-27 20:14=A0 =A0G4JNT=A0 =A00.503875=A0 =A0+13=A0 =A00=A0 =A0IO90iv=A0 =A0+23=A0 =A00.200=A0 =A0F6CNI=A0 =A0JN19qb=A0 =A0391=A0 =A0243=A0
=A02010-01-27 20:08=A0 =A0G4JNT=A0 =A00.503875=A0 =A0+10=A0 =A00=A0 =A0IO90iv=A0 =A0+23=A0 =A00.200=A0 =A0F6CNI=A0 =A0JN19qb=A0 =A0391=A0 =A0243=A0
=A02010-01-27 20:02=A0 =A0PA0A=A0 =A00.503900=A0 =A0+15=A0 =A00=A0 =A0JO33de=A0 =A0+37=A0 =A05.012=A0 =A0F6CNI=A0 =A0JN19qb=A0 =A0502=A0 =A0312=A0
=A02010-01-27 20:00=A0 =A0G4JNT=A0 =A00.503875=A0 =A0+14=A0 =A00=A0 =A0IO90iv=A0 =A0+23=A0 =A00.200=A0 =A0F6CNI=A0 =A0JN19qb=A0 =A0391=A0 =A0243=A0
=A02010-01-27 19:54=A0 =A0G7NKS=A0 =A00.503920=A0 =A0-5=A0 =A00=A0 =A0IO92ub=A0 =A0+20=A0 =A00.100=A0 =A0F6CNI=A0 =A0JN19qb=A0 =A0422=A0 =A0262=A0
=A02010-01-27 19:54=A0 =A0G4JNT=A0 =A00.503875=A0 =A0+14=A0 =A00=A0 =A0IO90iv=A0 =A0+23=A0 =A00.200=A0 =A0F6CNI=A0 =A0JN19qb=A0 =A0391=A0 =A0243=A0
=A02010-01-27 19:44=A0 =A0G4JNT=A0 =A00.503875=A0 =A0+10=A0 =A00=A0 =A0IO90iv=A0 =A0+23=A0 =A00.200=A0 =A0F6CNI=A0 =A0JN19qb=A0 =A0391=A0 =A0243=A0
=A02010-01-27 19:40=A0 =A0PA0A=A0 =A00.503900=A0 =A0+15=A0 =A00=A0 =A0JO33de=A0 =A0+37=A0 =A05.012=A0 =A0F6CNI=A0 =A0JN19qb=A0 =A0502=A0 =A0312=A0
=A0


Eingehende eMail ist virenfrei.
Von AVG =FCberpr=FCft - www.avg.de
Version:= 9.0.733 / Virendatenbank: 271.1.1/2649 - Ausgabedatum: 01/27/10 14:08:00=


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