Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-md06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 2FA8738000087; Wed, 12 Sep 2012 06:24:33 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1TBk61-0004Zb-JZ for rs_out_1@blacksheep.org; Wed, 12 Sep 2012 11:23:01 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1TBk61-0004ZS-0z for rsgb_lf_group@blacksheep.org; Wed, 12 Sep 2012 11:23:01 +0100 Received: from smtpout1.wanadoo.co.uk ([80.12.242.29] helo=smtpout.wanadoo.co.uk) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1TBk5y-0006G1-6c for rsgb_lf_group@blacksheep.org; Wed, 12 Sep 2012 11:22:59 +0100 Received: from AGB ([2.26.30.6]) by mwinf5d15 with ME id yANu1j00307vA0a03ANug7; Wed, 12 Sep 2012 12:22:57 +0200 Message-ID: <653FBF7D685F4CD8825D99885F4736E6@AGB> From: "Graham" To: References: <504E733E.5000208@iup.uni-heidelberg.de>,<8CF5E5BCA46639D-8FC-4829A@webmail-d050.sysops.aol.com> <7E7DFBB4D102A04DB5ADC88D66628A4A0FB22D26@ICTS-S-MBX5.luna.kuleuven.be> <82bc7bcd97ea679e8be267e8e2add69c@dl1dbc.net> In-Reply-To: <82bc7bcd97ea679e8be267e8e2add69c@dl1dbc.net> Date: Wed, 12 Sep 2012 11:22:53 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 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: SNR > reports 3 dB lower than actually present in the signal path. Unfortunately s/n levels are not that simple to determine or set , the original ROS , later Opera mode's where aligned with FLDIGI to give the same results . [...] 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 [80.12.242.29 listed in list.dnswl.org] X-Scan-Signature: 913d7a7c91a460d176c89ad756da16f9 Subject: Re: LF: RE: [rsgb_lf_group] Re: LF: slow WSPR? Content-Type: text/plain; format=flowed; charset="utf-8"; reply-type=response Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=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-sid: 3039ac1d605a505062e04a25 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none SNR > reports 3 dB lower than actually present in the signal path. Unfortunately s/n levels are not that simple to determine or set , the original ROS , later Opera mode's where aligned with FLDIGI to give the same results . After a set of test run in the US , using Path-sim , it was felt , the levels obtained where more realistic , and to enable better comparative testing , the s/n displayed was re-calibrated The Path-Sim software propagation simulator , which has a different set of parameters and gives a different level is now used as the reference. Its important to understand that the two modes . will never , give the same readings as wspr indicates the PEAK level , where Op indicates the AVERAGE s/n , wspr is aligned with FLDIGI and over a real path , the Op system is able to make use of deep variations in fading and is immure to phase and Doppler distortion. But , 'the eating of the pudding is in the proof of the making' ? Stefan , last night reaching ua0aet over land , with 7 dB left in the system, taking some big bites out of the distance records on 136 23:14 136 DK7FC de UA0AET Op32 5330 km -32 dB in Krasnoyarsk 73-G. -------------------------------------------------- From: "Sabine Cremer" Sent: Wednesday, September 12, 2012 8:46 AM To: Subject: LF: RE: [rsgb_lf_group] Re: LF: slow WSPR? > Hi Rik, > > thank you very much for the link to the results of your study. > > I was told often, that Opera is much more sensitive than WSPR. It was > interesting to learn that this might be the result of Opera giving SNR > reports 3 dB lower than actually present in the signal path. > > I think, there are some myths surrounding some digital modes... ;-) > > 73 > Sabine > > > Am 12.09.2012 08:55, schrieb Rik Strobbe: >> Hi Marcus, Stefan, All, >> >> Some kind of "WSPR8" (8 minutes wspr sequence) could indeed be tested >> by generating the WSPR8 signal (what is easy as WSPR is fully >> documented) and accelerate the recorded signal 4 times before feeding >> it into the WSPR software. But this method requires to reduce the >> WSPR8 bandwidth (frequency spacing between the tones) also by a factor >> of 4, from 6Hz to 1.5Hz. >> >> If you look at WSPR as an FM signal, the WSPR8 signal created that >> way will have the same modulation index as the original WSPR(2) >> signal, while a WSPR8 signal at the "old" 6Hz bandwidth would have a 4 >> times larger modulation index. And the modulation index affects the >> SNR. Thus the suggested method might not fully exploit the >> possibilities of WSPR8 (at unchanged bandwidth). >> >> BTW: the results of the SNR performance test are still available at >> http://on7yd.strobbe.eu [1]/QRSS/ [1]. >> >> 73, Rik ON7YD >> >> ------------------------- >> >> VAN: rsgb_lf_group@yahoogroups.co.uk >> [rsgb_lf_group@yahoogroups.co.uk] namens Markus Vester >> [markusvester@aol.com] >> VERZONDEN: dinsdag 11 september 2012 19:41 >> TO: rsgb_lf_group@blacksheep.org >> CC: edgarjtwining@virginbroadband.com.au; >> rsgb_lf_group@yahoogroups.co.uk >> ONDERWERP: [rsgb_lf_group] Re: LF: slow WSPR? >> >> Hi Stefan, LF, >> >> if I remember correctly, Rik's careful evaluaton of SNR performance >> in February resulted in a threshold for reliable decoding of -23 dB >> for Opera-2, versus -29 dB for WSPR. This is carrier power versus >> noise in 2.5 kHz, Opera "average power" reports are scaled 4 dB lower. >> Thus at same available ERP, WSPR would indeed have a 4x advantage in >> speed, and be equivalent to Opera-8. WSPR also transmits slightly more >> information, ie. locator field and power. >> >> Rik also looked at QRSS and DFCW, which at 100 % readability seemed >> to provide same or slightly higher throughput than Opera (with some >> depence on callsign length and viewing skills). >> >> Technically it would be straightforward to generate a slow WSPR >> transmission, and also certainly feasible to play back an accelerated >> recording. You'd have to get the timing right to fit to the 2-minute >> slots, and the web reports would probably show wrong frequencies, >> times and SNR. As Roger says, asking Joe Taylor for a modified version >> would be a better permanent solution. >> >> But whether slow or fast, it' still a digital mode, containing a >> blackbox producing either valid output or nothing at all. If you are >> after detection of the weakest possible signals, in my opinion the >> visual modes or even a straight carrier transmission will be the only >> way to see those "T" and "M" traces, along with the features of the >> noise or QRM which we are trying to overcome. >> >> Best 73, >> Markus (DF6NM) >> >> -----Ursprüngliche Mitteilung----- >> Von: Stefan Schäfer >> An: rsgb_lf_group >> Cc: Edgar J Twining >> Verschickt: Di, 11 Sept 2012 1:14 am >> Betreff: LF: slow WSPR? >> >> It's a pity that there is no slow-WSPR, e.g. needing 32 minutes or so. >> >> If WSPR (2 minutes FSK) is about as efficient as OP8 ( i heared so), >> >> then it should be a real alternative to the slow DX modes on LF but not >> >> on MF! >> >> There is a software that plays recorded audio files in a faster mode, so >> >> that QRSS becomes audible. VE2IQ has reported to me last year about it >> >> but i don't remember the name. >> >> Would it be possible to make our own slow WSPR by using that software >> >> and playing a 32 minute manipulated WSPR at 16x speed, feeding it to the >> >> normal WSPR rx software? The slower code could be generated outside the >> >> program. Would that be a useful test or do i miss something? >> >> 73, Stefan/DK7FC >> >> Am 10.09.2012 19:26, schrieb Graham: >> >>> May be Mal >> >>> >> >>> But once again Jim has the answer to this problem ..if you can >> >>> find his articles after Google trashed the uk500khz news group , >> >>> >> >>> I think Jose R predicts a 6 dB gain by changing to PSK from >> >>> the Opera on/off keying but that would prevent most of the >> >>> LH/MF usage >> >>> >> >>> G.. >> >>> >> >> __._,_.___ >> >> Reply to sender | Reply to group | Reply via web post [2] | Start a >> new topic [3] Messages in this topic [4] (1) >> Recent Activity: >> >> * New Members [5] 1 >> >> Visit Your Group [6] >> [7] >> Switch to: Text-Only, Daily Digest • Unsubscribe • Terms of Use [8] >> >> . >> >> __,_._,___ >> >> Links: >> ------ >> [1] http://on7yd.strobbe.eu/QRSS/ >> [2] >> >> http://uk.groups.yahoo.com/group/rsgb_lf_group/post;_ylc=X3oDMTJxZ2FmaWxkBF9TAzk3NDkwNTA1BGdycElkAzg1MDgwODk1BGdycHNwSWQDMTY5MDA2MzEwOARtc2dJZAMxMDI0BHNlYwNmdHIEc2xrA3JwbHkEc3RpbWUDMTM0NzM4NTMwMA--?act=reply&messageNum=1024 >> [3] >> >> http://uk.groups.yahoo.com/group/rsgb_lf_group/post;_ylc=X3oDMTJmZzNtaWo0BF9TAzk3NDkwNTA1BGdycElkAzg1MDgwODk1BGdycHNwSWQDMTY5MDA2MzEwOARzZWMDZnRyBHNsawNudHBjBHN0aW1lAzEzNDczODUzMDA- >> [4] >> >> http://uk.groups.yahoo.com/group/rsgb_lf_group/message/1024;_ylc=X3oDMTM1bTRxaDljBF9TAzk3NDkwNTA1BGdycElkAzg1MDgwODk1BGdycHNwSWQDMTY5MDA2MzEwOARtc2dJZAMxMDI0BHNlYwNmdHIEc2xrA3Z0cGMEc3RpbWUDMTM0NzM4NTMwMAR0cGNJZAMxMDI0 >> [5] >> >> http://uk.groups.yahoo.com/group/rsgb_lf_group/members;_ylc=X3oDMTJnMnFsMGJtBF9TAzk3NDkwNTA1BGdycElkAzg1MDgwODk1BGdycHNwSWQDMTY5MDA2MzEwOARzZWMDdnRsBHNsawN2bWJycwRzdGltZQMxMzQ3Mzg1MzAw?o=6 >> [6] >> >> http://uk.groups.yahoo.com/group/rsgb_lf_group;_ylc=X3oDMTJmMG81aDJ1BF9TAzk3NDkwNTA1BGdycElkAzg1MDgwODk1BGdycHNwSWQDMTY5MDA2MzEwOARzZWMDdnRsBHNsawN2Z2hwBHN0aW1lAzEzNDczODUzMDA- >> [7] >> >> http://uk.groups.yahoo.com/;_ylc=X3oDMTJlN2NuYXZpBF9TAzk3NDkwNTAzBGdycElkAzg1MDgwODk1BGdycHNwSWQDMTY5MDA2MzEwOARzZWMDZnRyBHNsawNnZnAEc3RpbWUDMTM0NzM4NTMwMA-- >> [8] http://uk.docs.yahoo.com/info/terms.html > >