Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-db02.r1000.mx.aol.com (Internet Inbound) with ESMTP id C438E380000B1 for ; Wed, 8 Feb 2012 15:47:16 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RvE47-0004Iu-Lg for rs_out_1@blacksheep.org; Wed, 08 Feb 2012 20:24:31 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RvE47-0004Il-5H for rsgb_lf_group@blacksheep.org; Wed, 08 Feb 2012 20:24:31 +0000 Received: from mail-gy0-f171.google.com ([209.85.160.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RvE44-00014O-9j for rsgb_lf_group@blacksheep.org; Wed, 08 Feb 2012 20:24:31 +0000 Received: by ghbf1 with SMTP id f1so743414ghb.16 for ; Wed, 08 Feb 2012 12:24:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; bh=c9MkqLyCuUSX+hfPsO8WAYIRhqkrBmZPIeqi2faDqZE=; b=NgS1ZQdVfFkBBb6m1nD7Zl/OlZHSZ78912y20ke7xb8S8HA4ffclO28WywHVbESHBE XOzmOGsYXFIwexVV2CqrizBmcI/FAlhknY8vl+5xXR+1fJ0Zdtu/pTD69VUwP23JGdnM YqdUzlx8NSyFL2d9zs5gGrpiZxmVhguOyy25U= MIME-Version: 1.0 Received: by 10.50.89.232 with SMTP id br8mr25613127igb.30.1328732661690; Wed, 08 Feb 2012 12:24:21 -0800 (PST) Received: by 10.231.12.140 with HTTP; Wed, 8 Feb 2012 12:24:21 -0800 (PST) In-Reply-To: References: Date: Wed, 8 Feb 2012 20:24:21 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: QRSS3 "challenge" results Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none 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-SCORE: 0:2:480979296:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d021.2 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d40564f32df540fb4 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none You don't need a linear PA for WSPR. It is constant amplitude MFSK. Timing only has to be within a few seconds, and an internet time server can do that You will need an upconverter though - which I assume is what you meant - Of course, there always direct generation available... Andy G4JNT On 8 February 2012 20:17, Roger Lapthorn wrote: > Rik's comment that WSPR is roughly equivalent to QRSS10 is interesting an= d > ties up well with my own experience: with QRPp and a small antenna QRSS3 = was > a struggle (100km) , QRSS30 got me a decent distance (300km +) and WSPR g= ot > me somewhere in the middle (250km) . > > It still surprises me that more people don't use WSPR on 136kHz for > beaconing when it is stable, reliable, very well documented and has all t= he > advantages of an internet database to almost instantly check how well you= r > signal is being propagated. I guess the disadvantages are the need for a > linear PA and the timing accuracy. I've still not re-installed OPERA as I > know it would be a CPU struggle with my PC. > > 73s > Roger G3XBM > > > > On 8 February 2012 18:32, James Moritz wro= te: >> >> Dear Andy, Rik, LF Group, >> >> >> G4JNT wrote: >> ...>When you generasted the Opera and WSPR audio files, did you take int= o >> account that Opera should be compared using the mean power? =A0With its >> 50% duty cycle, this means an Opera Tx has to have twice the power >> rating of one running WSPR for equal S/N ratios...> >> >> ... But on the other hand, you could argue that since the TX power is in >> practice normally limited by the PEP available from the PA. So by having >> 100% duty cycle, WSPR effectively doubles the available average output p= ower >> from a given transmitter, compared to Opera. I suppose it depends whethe= r >> you are more worried about corona on the antenna, or your electricity bi= ll >> ;-) >> >> I think it is interesting that there is only a small difference between >> "average" and "top 10" operators - down to about 70% correct copy, there >> appears be less than 1dB =A0between "good" and "average". Surely any low= er >> levels of accuracy would be pretty useless for communicating information= , >> even in an amateur context. This suggests the "human factor" in QRSS >> reception is perhaps quite a small factor. >> >> Cheers, Jim Moritz >> 73 de M0BMU >> >> >> >> >> >> >> >> >> >> If you used peak power (ie. the same transmitter amplitude), the curve >> plotted for Opera will have to move 3dB to the right, making it more >> comparable with WSPR - and then more as one would expect. >> >> Given the similarity of the error correction overhead for Opera and >> WSPR, =A0and nearly matching symbol rate for OP2 ,and that OOK and FSK >> have comparable error rates for the same mean power, suggests the two >> modes should give roughly similar performance. >> >> Only 27 responses, that doesn't seem very many compared with the >> numbers that monitor this reflector. >> >> Andy =A0G4JNT >> >> >> On 8 February 2012 16:00, Rik Strobbe wrot= e: >>> >>> Dear all, >>> >>> the results of the "QRSS3 challenge" can be found at >>> http://on7yd.strobbe.eu/QRSS/ >>> Hit refresh if you still see the old challenge. >>> >>> Thanks to all who participated ! >>> >>> 73, Rik ON7YD - OR7T >>> >>> ________________________________ >>> Van: Rik Strobbe >>> Verzonden: donderdag 2 februari 2012 18:17 >>> Aan: rsgb_lf_group@blacksheep.org >>> Onderwerp: QRSS3 "challenge" >>> >>> Dear all, >>> >>> >>> >>> as mentioned some days ago I generated a whole series of Opera, WSPR >>> and QRSS3 audio with a known SNR. >>> >>> For Opera and WSPR it was easy to determine the lowest SNR for a proper >>> decode. But for QRSS3 it is much more difficult as it depends on the >>> operators "sharp eye". It must be somewhere in the range of -24 to -28d= B >>> SNR >>> (@ 2.5kHz BW). >>> >>> Today I did put all the QRSS3 screenshots in this range in a >>> website, where you can fill in what you see (decode) for each screensho= t. >>> >>> I would like to invite all of you to give it a try and send me the >>> results >>> (the more entries the better the statistics). >>> >>> After some time (Feb 10th) will put all results into some nice tables >>> and graphs and make them available. >>> >>> Of course no personal (individual) results will be published. But based >>> on >>> the results every participant (who keeps his results) can see where he >>> ends. >>> >>> >>> >>> The "QRSS3 Challenge" can be found at http://on7yd.strobbe.eu/QRSS/ >>> >>> >>> >>> 73, Rik ON7YD - OR7T >> >> >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 2012.0.1913 / Virus Database: 2112/4795 - Release Date: 02/07/1= 2 >> >> >> > > > > -- > http://qss2.blogspot.com/ > http://g3xbm-qrp.blogspot.com/ > http://www.g3xbm.co.uk > https://sites.google.com/site/sub9khz/ > >