Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mk04.r1000.mx.aol.com (Internet Inbound) with ESMTP id B0B593800009D; Thu, 27 Dec 2012 18:44:35 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ToN6z-0000fF-E6 for rs_out_1@blacksheep.org; Thu, 27 Dec 2012 23:43:41 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ToN6y-0000f6-PX for rsgb_lf_group@blacksheep.org; Thu, 27 Dec 2012 23:43:40 +0000 Received: from imr-ma05.mx.aol.com ([64.12.100.31]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1ToN6v-00085i-RD for rsgb_lf_group@blacksheep.org; Thu, 27 Dec 2012 23:43:39 +0000 Received: from mtaout-db02.r1000.mx.aol.com (mtaout-db02.r1000.mx.aol.com [172.29.51.194]) by imr-ma05.mx.aol.com (Outbound Mail Relay) with ESMTP id F0B821C000060 for ; Thu, 27 Dec 2012 18:43:15 -0500 (EST) Received: from White (nrbg-4dbe6672.pool.mediaWays.net [77.190.102.114]) by mtaout-db02.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id D06C7E0000A9 for ; Thu, 27 Dec 2012 18:43:12 -0500 (EST) Message-ID: From: "Markus Vester" To: References: <75B6FFD76D0C416FAA1297187CAF180B@AGB> <50DCA649.2010601@iup.uni-heidelberg.de> <50DCB457.1070302@iup.uni-heidelberg.de> Date: Fri, 28 Dec 2012 00:43:11 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 12.0.1606 X-MimeOLE: Produced By Microsoft MimeOLE V12.0.1606 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1356651795; bh=XRq3xjkr3986NMJigRw4DYSIMz1d8l9V4+bf2UDvlaw=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=Du9ZpCdqlX5sO0jmBzaIdIHn065aZ1C9QALUes+GyVN6mhjTlT5HONLyff3EIVCBX J/z/Pte4c7PM6G41db/KVhLZtObXuUkk0ZXuyDsLsawBSNyMvfWVDnhDBCdumTw+lE qEyoFcGYgt0UsXNfpoLhQay9Sd4IPFiONqCUM19k= X-AOL-SCOLL-SCORE: 0:2:392313920:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-Spam-Score: 0.0 (/) 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: Hi Stefan, Graham, I think Graham's statement is not that far off. From memory, I believe that the best Australian receptions of DK7FC peaked around 12 dB SNR in 11 mHz FFT (eg VK1SV on March 18). The noise bandwidth is 16 mHz ie -18 dBHz or -52 dB vs 2.5 kHz. Thus the SNR would have been -44 dB in 2.5 kHz, corresponding to -48 dB on the Opera average-power scale. There was slow QSB which limited the time window of best SNR to some 20 minutes, but otherwise no visible indications of multipath Doppler or chirp. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [64.12.100.31 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 6ae5fe68d6708d1e4a9cbdf0f0af43e5 Subject: LF: Opera to VK? (was WE6XGR 0P8...) Content-Type: multipart/alternative; boundary="----=_NextPart_000_001C_01CDE494.50386BA0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=HTML_30_40,HTML_MESSAGE, MISSING_OUTLOOK_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-mk04.r1000.mx.aol.com ; domain : mx.aol.com DKIM : fail X-AOL-OVERRIDE-PIK-REASON: Y x-aol-sid: 3039ac1d618850dcdd621ba8 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_001C_01CDE494.50386BA0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Stefan, Graham, I think Graham's statement is not that far off. >From memory, I believe that the best Australian receptions of DK7FC = peaked around 12 dB SNR in 11 mHz FFT (eg VK1SV on March 18). The noise = bandwidth is 16 mHz ie -18 dBHz or -52 dB vs 2.5 kHz. Thus the SNR would = have been -44 dB in 2.5 kHz, corresponding to -48 dB on the Opera = average-power scale. There was slow QSB which limited the time window of = best SNR to some 20 minutes, but otherwise no visible indications of = multipath Doppler or chirp. According to Rik's evaluation, Opera-2 decodes reliably at -23 dB = carrier power in 2.5 kHz. Slowing to 32 minutes gains 12 dB, thus the = Op-32 threshold is -35 dB in 2.5 kHz, or -39 dB on the Op scale. Often = Opera has been claimed to go 2 dB further down (to -41 dB Op scale), but = I believe this may be based on sporadic "lucky" decodes due to = favourable noise statistics. BTW these do show up with other modes as = well, for example WSPR occasionally gets -32 dB spots, way below its = nominal threshold of -29 dB. The Opera "deep search" correlation method is still under development, = but so far it looks like it can indeed reliably detect and identify = coherent Op-32 signals 10 dB below standard Opera decoding (ie -49 dB Op = scale). This means that in the best-case, an Op-32 signal from Stefan = could have been detected in VK with a theoretical 1 dB margin. =20 For comparison, JT9-30 should decode down to -42 dB / 2.5 kHz, ie. 7 dB = better than the standard Opera decoder, and 2 dB "short of VK".=20 Of course we have to keep in mind that these dBs are more or less = ballpark numbers, and the whims of propagation and background noise may = add (or more likely subtract) several of them at any time...=20 Best 73, Markus (DF6NM) =20 From: Stefan Sch=E4fer=20 Sent: Thursday, December 27, 2012 9:49 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: Fw: WE6XGR 0P8 498KHz DIAL 2200 Z TO NIGHT Am 27.12.2012 21:18, schrieb Graham:=20 [...]=20 I think using the correlation 10 dB gain , Markus has found = using OP32 , you would have a confirmed decode in VK by now and = possibly a OP32 decode as well Did he? :-) Markus, is that realistic? 73, Stefan , where M-C is looking for a pattern match , the decode = engine is extracting data , but from the other angle a = confirmation is the only criteria : ) 73 -G.. ------=_NextPart_000_001C_01CDE494.50386BA0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Stefan, Graham,
 
I think Graham's statement is not = that far=20 off.
 
From memory, I believe that the = best=20 Australian receptions of DK7FC peaked around 12 dB SNR in 11 mHz = FFT (eg=20 VK1SV on March 18). The noise bandwidth is 16 mHz ie -18 dBHz = or -52=20 dB vs 2.5 kHz. Thus the SNR would have been -44 = dB in 2.5=20 kHz, corresponding to -48 dB on the Opera average-power = scale. There was=20 slow QSB which limited the time window of best SNR to some 20 = minutes, but=20 otherwise no visible indications of multipath Doppler=20 or chirp.
 
According to Rik's evaluation, Opera-2 = decodes=20 reliably at -23 dB carrier power in 2.5 kHz. Slowing to = 32=20 minutes gains 12 dB, thus the Op-32 threshold is -35 dB in 2.5 = kHz, or=20 -39 dB on the Op scale. Often Opera = has been=20 claimed to go 2 dB further down (to -41 dB Op scale), but I believe = this=20 may be based on sporadic "lucky" decodes due to favourable = noise=20 statistics. BTW these do show up with other modes as=20 well, for example WSPR occasionally gets -32 dB spots, = way below=20 its nominal threshold of -29 dB.
 
The Opera "deep search" correlation = method is still=20 under development, but so far it looks like it can indeed reliably = detect=20 and identify coherent Op-32 signals 10 dB below standard Opera decoding = (ie -49=20 dB Op scale). This means that in = the=20 best-case, an Op-32 signal from Stefan could have been=20 detected in VK with a theoretical 1 dB margin.
   
For comparison, JT9-30 should decode = down to -42 dB=20 / 2.5 kHz, ie. 7 dB better than the standard Opera decoder, = and 2 dB=20 "short of VK".
 
Of course we have to keep in mind that = these dBs=20 are more or less ballpark numbers, and the whims of propagation and = background noise may add (or more likely subtract) several of them = at any=20 time... 
 
Best 73,
Markus (DF6NM)

 
From: Stefan = Sch=E4fer
Sent: Thursday, December 27, 2012 9:49 PM
To: rsgb_lf_group@blacksheep.org= =20
Subject: Re: LF: Fw: WE6XGR 0P8 498KHz DIAL 2200 Z TO=20 NIGHT


Am = 27.12.2012 21:18,=20 schrieb Graham:=20
[...]=20
I think  using  the correlation  10 dB  gain = ,=20 Markus  has  found  using  OP32 , you  = would =20 have a  confirmed  decode  in VK by  now  = and =20 possibly  a OP32  decode as  well
Did = he?=20 :-)
Markus, is that realistic?
73, Stefan
  , where  M-C   is looking  for  a = pattern  match , the  decode engine  is  = extracting=20 data  , but   from the  other angle  = a  =20 confirmation  is the  only  criteria : )
 
73 -G..
 
------=_NextPart_000_001C_01CDE494.50386BA0--