Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mk03.r1000.mx.aol.com (Internet Inbound) with ESMTP id 8385C3800010C; Wed, 24 Aug 2011 14:37:51 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QwIJo-0008KX-A9 for rs_out_1@blacksheep.org; Wed, 24 Aug 2011 19:36:52 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QwIJm-0008KO-UO for rsgb_lf_group@blacksheep.org; Wed, 24 Aug 2011 19:36:50 +0100 Received: from nm6.bullet.mail.ne1.yahoo.com ([98.138.90.69]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1QwIJk-0006RH-MB for rsgb_lf_group@blacksheep.org; Wed, 24 Aug 2011 19:36:50 +0100 Received: from [98.138.90.51] by nm6.bullet.mail.ne1.yahoo.com with NNFMP; 24 Aug 2011 18:36:41 -0000 Received: from [98.138.89.175] by tm4.bullet.mail.ne1.yahoo.com with NNFMP; 24 Aug 2011 18:36:41 -0000 Received: from [127.0.0.1] by omp1031.mail.ne1.yahoo.com with NNFMP; 24 Aug 2011 18:36:41 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 384430.82566.bm@omp1031.mail.ne1.yahoo.com Received: (qmail 40937 invoked by uid 60001); 24 Aug 2011 18:36:41 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com.ar; s=s1024; t=1314211001; bh=gzE7umhbPCuD+LAMbhgwET0m6OgkSx4f4Hts8zVWiM0=; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=fuIhGz/5ajID65RVKmyZkQqEjHtIs3qsYXXj9kQxQJrxrNAZXfr0ZPFhJdkDjgKGCNILakKH5cuOhyWFgWVZ8bwMsoZHlpxaJX2miosY4WXbFa1U63nFA6EILtl1o4z1l6/bmBnNR0pgy/8rVs6mAWeJM/RxuEr4Z1d2ozgWEf8= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.ar; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=AKryWKo7ef4FJ155qpxsPwrYi3CIX++VblJplIonDbGU4+WaFUVgOx7UZ23nZXHfqmuhiuKRCxgca4p7KxpEXffgNaNx4lQdDXiSbyEgEpl8PVU0qKcOVQ0nTxZWSJvqkrS7KFasXADMqDBxSz9vkepH2447Zs1TWUTBFOFNhj0=; X-YMail-OSG: rLjo8zcVM1nBchAtFkeB1UQORCIjBgNUbhm6Av1kaiZv__P ITHAZ1GPAAzyxMmwRTL8pPJUvfUF_2DL.L8eoyWDrjAv0SMycQV5tHKr66bv lWcKuLGMJENxLQoR9_AFMYG8Oz6GzYrWGWEVV3hb3lRBgQD23gYE2oifHkp_ cyP4rMP92yIk3BZ7vG61cBJqHpzEbBNFTd.T523GzOlmuISp.RqUVUEM5t6K pKpWJL8VR3nQ0FD1_lzSXVi7eCqCeBDfE72x3ZSbbNkoyfgKOXnTzFN9wjeV AQsHUaSaqo3.zAC4B8Ngc..UZYsbcodYHE1hvvco8WamWXbqlvCj9hz2VMtj Azoams.KsKAJNN5I0_FLCDt6pd2XzSci9_bpN3q_v.9e0.OMA0xRpAQHdyG_ obtHfAlIfEBFYgwo5w2awRC0wdqQ78.1Fau8XtgRU0LlGksPHPD6UBZlBtsp Wjxn5ewTLCPZOCaUgF9VazeoMMy90E8D5mAvtdGB6yINkcm6f4sqfY0Kk25d qUWqbWVa6xEgsUU7adbMp5KUshDPaqmu4wrVN7d87np9FOg0lJkycQ8M4yOJ LzhAio9U3zhkyxzoGqLg4_hNWPMRQOfwok6r0kHQJOMPjZsLTV3OYvsycRQg Er2rhuiPzRkFhJ3j7SQDm_WcigcsebzkTmL1GYvWc8MWmO2t18Wn.nUQ2SZW P.sQNHZADbPwOJDQAyiTrKKz2952qp2Top2cgtw-- Received: from [186.38.16.70] by web125716.mail.ne1.yahoo.com via HTTP; Wed, 24 Aug 2011 11:36:41 PDT X-Mailer: YahooMailWebService/0.8.113.313619 References: <790E5582101F4A069156B4677843CD78@AGB> <007f01cc6286$0f541490$0401a8c0@xphd97xgq27nyf> Message-ID: <1314211001.22166.YahooMailNeo@web125716.mail.ne1.yahoo.com> Date: Wed, 24 Aug 2011 11:36:41 -0700 (PDT) From: Marcelino Garcia To: "rsgb_lf_group@blacksheep.org" In-Reply-To: MIME-Version: 1.0 DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: WSPR or QRSS: which is better? Content-Type: multipart/alternative; boundary="0-1497619805-1314211001=:22166" 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_20_30, HTML_FONTCOLOR_UNSAFE,HTML_MESSAGE,TO_ADDRESS_EQ_REAL 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: 0:2:449920608:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d233.1 ; domain : yahoo.com.ar DKIM : fail x-aol-sid: 3039ac1d61874e5544ff6d5c X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --0-1497619805-1314211001=:22166 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Roger,=0A=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 I fully agree with your statemen= ts, but I'm afraid that with a minimalist home made CW transmitter, let's s= ay just a one transistor xtal oscillator, it's not=A0 possible to use WSPR,= for this mode a little more complex transmitter, may be SDR based, should = be used.=0A73,=0AMarcelino - LU7DSU=0A=0A=0A=0A____________________________= ____=0ADe: Roger Lapthorn =0APara: rsgb_lf_group@b= lacksheep.org=0AEnviado: mi=E9rcoles, 24 de agosto de 2011 15:18=0AAsunto: = Re: LF: WSPR or QRSS: which is better?=0A=0A=0AMal=0A=0AThanks again for yo= ur comments, some of which are valid.=A0 =0A=0AThere are times when CW is u= seful and times when more efficient modes like WSPR really win out. =0A=0AA= s I have said countless times now, no other mode apart from WSPR that I kno= w of is able to give me almost instant feedback (via the internet database)= at a distance that (a) my signal is being received at all, (b) how far it = is getting, and (c) how strong it is. To be able to get this information wh= en using simple, low powered and home made equipment is extremely useful. A= small change in the PA output or antenna efficiency is measurable. =0A=0AI= t really comes down to what is the purpose of our experiments: being able t= o make CW contacts is a perfectly reasonable aim - please carry on. In my c= ase it is to see just what is possible with minimalist (hardware) equipment= on the VLF, LF and MF bands. Yes, I am gaining valuable dBs by the use of = efficient coding systems and clever PC software, but I see nothing wrong in= that.=0A=0AAnd finally, please do NOT call me an appliance operator: all m= y VLF-MF equipment is home-made as is much of my HF and VHF gear. I am happ= y to use modern technology to enhance my enjoyment of the hobby and to expl= oit weak signal modes but I am equally happy to have a CW QSO on any band w= hen the opportunity arises.=0A=0A73s=0ARoger G3XBM=0A=0A=0A=0A=0AOn 24 Augu= st 2011 18:48, mal hamilton wrote:=0A=0A =0A>Jim ta= ke NOTE=0A>Impulsive noise generates a random output that looks like =0Aa v= alid callsign so this is also=A0inventing a signal that you imagine to =0Ae= xist.=0A>An immediate positive ID, don't depend on it =0A!!=0A>An appliance= communications operator is easily =0Ahoodwinked.=0A>Bletchley Park CW=A0= =A0expert Radio Operators =0Amanaged to piece messages together and achieve= d the object., and no doubt used =0Aimagination. =0A>No expertise is need t= o send/receive wspr and for that =0Amatter a lot of other appliance operato= r modes, know in the services today as =0AIDIOT PROOF comms black=A0boxes.= =0A>For a commercial operator that needs to shift thousands of =0Amessages = worldwide then automated digital modes are necessary and useful, but =0Afor= a radio hobbyist its like using a sledge hammer to crack the proverbial = =0Anut=0A>=A0=0A>g3kev=0A>=A0=0A>=A0=0A>=A0=0A>=A0=0A>=A0Original Message -= ---- =0A>From: Andy Talbot =0A>>To: rsgb_lf_group@blacksheep.org =0A>>Sent= : Wednesday, August 24, 2011 6:06 PM=0A>>Subject: Re: LF: WSPR or QRSS: wh= ich is better?=0A>>=0A>>=0A>>I know what you're referring to.=A0 In cases = of impulsive noise, there is a finite=A0probability of=A0something eventua= lly =A0getting through the decoder and being flagged as valid.=A0 The very= nature of heavy source coding, means that the resulting random output wil= l look like a valid callsign.=A0=A0 However, WE then apply the next level = of error detection, by knowing the combination must be rubbish.=0A>>=A0=0A= >>'jnt=A0=A0 [and there is another=A0example of source coding]=0A>>=0A>>= =0A>>=A0=0A>>On 24 August 2011 17:47, Graham wrot= e:=0A>>=0A>> =0A>>>>>=A0 and gives absolutely guaranteed error free decodin= g, or nothing at all.=A0 <<=0A>>>=A0=0A>>>Are you sure ?=A0=0A>>>=A0=0A>>>= G..=0A>>>=0A>>>=0A>>>From: Andy Talbot =0A>>>Sent: Wednesday, August 24, 20= 11 5:12 PM=0A>>>To: rsgb_lf_group@blacksheep.org =0A>>>Subject: Re: LF: WSP= R or QRSS: which is better?=0A>>>=0A>>>=0A>>>WSPR works=A0in a 1.46Hz sign= al bandwidth and because of its very high level of error correction and so= ft-decision decoding, means that=A0it will work at a S/N of about 3dB in t= his bandwidth, and sometimes a bit lower still=A0 (Normally, FSK with no c= orrection at all=A0needs about 10 - 12dB S/N for near error-free performan= ce)=0A>>>=A0=0A>>>QRSS=A0has to show about 6 - 10dB in its signal bandwidth= to be able to discern fully what is sent, although a slightly lower S/N m= ay be useable when you 'know' what you should be receiving.=A0 (A form of = forward error correction is now in use here as well perhaps=A0:-)=A0 So le= ts say 5dB S/N is a working value..=0A>>>=A0=0A>>>So take=A03dB in 1.46Hz= =A0as a starting point and derive the bandwidth for QRSS needed to get 5dB= S/N with the same signal.=A0 This will have to be narrower to get a 2dB h= igher S/N and works out as 1.46=A0/ 10^(2/10) =3D 0.92Hz=0A>>>=A0=0A>>>So = QRSS used with a 0.9Hz bandwidth - which I think means about a 2 - 3s dot = period ought to be decoded at the same S/N as a WSPR signal.=A0=A0 Which i= s probably the info you wanted.=0A>>>=A0=0A>>>But now compare source coding= efficiencies.=A0=A0 WSPR fits a callsign, locator and power level into a = 110 second transmission - and gives absolutely guaranteed error free decod= ing, or nothing at all.=A0=A0About 12 characters in actuality, but that is= being a bit unfair as the coding forces certain callsign and locator for= matting.=A0=A0 So in all probablility, more like 7 or 8 effective characte= rs (I'm being a bit empirical here)=0A>>>=A0=0A>>>Assuming standard QRSS - = not DFCW - , which if like standard Morse, then 5 characters takes about 5= 0 dot symbols to send (12WPM =3D 60 chars in 1 minute, =3D 1 char / second= , or about 10 dot periods / second.=A0=A0=A0 Dot speed =3D WPM / 1.2) =A0 = If we have 2s dots, that is 5 characters can be sent=A0in the time for a W= SPR transmission.=0A>>>=A0=0A>>>So as a quick estimate, WSPR wins by=A0rou= ghly 2dB in S/N terms for a given dot period / noise bandwidth.=A0 And at = similar S/N values, WSPR is about 1.5 times faster=0A>>>Andy=0A>>>www.g4jn= t.com=0A>>>=A0=0A>>>=A0=0A>>>=A0=0A>>>=A0=0A>>>On 24 August 2011 16:42, Rog= er Lapthorn wrote:=0A>>>=0A>>>A question for the= coding experts here: WSPR is an excellent weak signal beaconing mode, but= at what QRSS speed is QRSS "better" ?=0A>>>>=0A>>>>73s=0A>>>>Roger G3XBM= =0A>>>>=0A>>>>-- =0A>>>>http://g3xbm-qrp.blogspot.com/=0A>>>>http://www.g3x= bm.co.uk=0A>>>>http://www.youtube.com/user/g3xbm=0A>>>>https://sites.google= .com/site/sub9khz/=0A>>>>=0A>>>>=0A>>>=0A>>>=0A>>>=0A>>=0A=0A=0A-- =0Ahttp:= //g3xbm-qrp.blogspot.com/=0Ahttp://www.g3xbm.co.uk=0Ahttp://www.youtube.com= /user/g3xbm=0Ahttps://sites.google.com/site/sub9khz/ --0-1497619805-1314211001=:22166 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Roger,
         &= nbsp;  I fully agree with your statements, but I'm afraid that with a = minimalist home made CW transmitter, let's say just a one transistor xtal o= scillator, it's not  possible to use WSPR, for this mode a little more= complex transmitter, may be SDR based, should be used.
73,
Marcelino - LU7DSU

De: Roger Lapt= horn <rogerlapthorn@gmail.com>
Para: rsgb_lf_group@blacksheep.org
Enviado: mi=E9rcoles, 24 de agosto de 2011 1= 5:18
Asunto: Re: LF: WS= PR or QRSS: which is better?

Mal
=
Thanks again for your comments, some of which are valid. 

= There are times when CW is useful and times when more efficient modes like = WSPR really win out.

As I have said countless times now, no other m= ode apart from WSPR that I know of is able to give me almost instant feedba= ck (via the internet database) at a distance that (a) my signal is being re= ceived at all, (b) how far it is getting, and (c) how strong it is. To be a= ble to get this information when using simple, low powered and home made eq= uipment is extremely useful. A small change in the PA output or antenna eff= iciency is measurable.
=0A
It really comes down to what is the purpo= se of our experiments: being able to make CW contacts is a perfectly reason= able aim - please carry on. In my case it is to see just what is possible w= ith minimalist (hardware) equipment on the VLF, LF and MF bands. Yes, I am = gaining valuable dBs by the use of efficient coding systems and clever PC s= oftware, but I see nothing wrong in that.
=0A
And finally, please do = NOT call me an appliance operator: all my VLF-MF equipment is home-made as = is much of my HF and VHF gear. I am happy to use modern technology to enhan= ce my enjoyment of the hobby and to exploit weak signal modes but I am equa= lly happy to have a CW QSO on any band when the opportunity arises.
=0A<= br>73s
Roger G3XBM



On 24 August 2011 18:48, mal hamilton <g3kevmal@talktalk.net> wrote:
=
=0A=0A=0A=0A=0A=0A=0A=0A
Jim take NOTE
=0A
Impulsive noise generates a random output that looks like =0Aa v= alid callsign so this is also inventing a signal that you imagine to = =0Aexist.
=0A
An immediate positive ID= , don't depend on it =0A!!
=0A
An appl= iance communications operator is easily =0Ahoodwinked.
=0A
= Bletchley Park CW  expert Radio Operators = =0Amanaged to piece messages together and achieved the object., and no doub= t used =0Aimagination.
=0A
No experti= se is need to send/receive wspr and for that =0Amatter a lot of other appli= ance operator modes, know in the services today as =0AIDIOT PROOF comms bla= ck boxes.
=0A
For a commercial op= erator that needs to shift thousands of =0Amessages worldwide then automate= d digital modes are necessary and useful, but =0Afor a radio hobbyist its l= ike using a sledge hammer to crack the proverbial =0Anut
=0A 
=0A
g3kev
=0A
 
=0A
 = ;
=0A
 
=0A
 
=0A
 Original Message -----
= =0A
=0A
From: =0A Andy =0A Talbot
=0A =0A
Sent: Wednesday, August 24, 2011 6:= 06 =0A PM
=0A
Subject: Re: LF: WSPR or QRSS: which is =0A = better?
=0A

=0A
I know what you're referring to= .  In cases of impulsive noise, there =0A is a finite probabilit= y of something eventually  getting =0A through the decoder and b= eing flagged as valid.  The very nature of heavy =0A source coding, m= eans that the resulting random output will look like a valid =0A callsign.=    However, WE then apply the next level of error =0A detection,= by knowing the combination must be rubbish.
=0A
 
=0A=
'jnt   [and there is another example of source =0A c= oding]
=0A


 
=0A
On 24 August 2011 17:47, Graham <g8fzk@g8fzk.fsnet.co.uk> = =0A wrote:
=0A
<= /u>=0A
=0A
=0A
>>  and gives absolutely guaranteed= error free decoding, or =0A nothing at all.  <<
=0A =
 
=0A
Are you = sure ? 
=0A
 
=0A
G..
= =0A
=0A

=0A
=0A
Fro= m: Andy Talbot
=0A
=0A
Sent: Wednesday, Au= gust 24, 2011 5:12 PM
=0A =0A
Subject: Re: LF: WSPR = or QRSS: which is =0A better?
=0A

=0A
=0A
=0A
=0A
WSPR works in= a 1.46Hz signal bandwidth and because of its very =0A high level of err= or correction and soft-decision decoding, means =0A that it will wo= rk at a S/N of about 3dB in this bandwidth, and =0A sometimes a bit lowe= r still  (Normally, FSK with no correction at =0A all needs ab= out 10 - 12dB S/N for near error-free performance)
=0A
 <= /div>=0A
QRSS has to show about 6 - 10dB in its signal bandwid= th to be able =0A to discern fully what is sent, although a slightly low= er S/N may be useable =0A when you 'know' what you should be receiving.&= nbsp; (A form of forward error =0A correction is now in use here as well= perhaps :-)  So lets say 5dB =0A S/N is a working value..=0A
 
=0A
So take 3dB in 1.46Hz as a = starting point and derive the =0A bandwidth for QRSS needed to get 5dB S= /N with the same signal.  This =0A will have to be narrower to get = a 2dB higher S/N and works out as =0A 1.46 / 10^(2/10) =3D 0.92Hz=0A
 
=0A
So QRSS used with a 0.9Hz bandwidth= - which I think means about a 2 - =0A 3s dot period ought to be decoded= at the same S/N as a WSPR =0A signal.   Which is probably the= info you wanted.
=0A
 
=0A
But now compare = source coding efficiencies.   WSPR fits a =0A callsign, locato= r and power level into a 110 second transmission - and gives =0A absolut= ely guaranteed error free decoding, or nothing at =0A all.  Ab= out 12 characters in actuality, but that is being a bit =0A unfair as th= e coding forces certain callsign and locator =0A formatting.  = So in all probablility, more like 7 or 8 effective =0A characters (I'm = being a bit empirical here)
=0A
 
=0A
Assumi= ng standard QRSS - not DFCW - , which if like standard Morse, =0A then 5= characters takes about 50 dot symbols to send (12WPM =3D 60 chars in 1 =0A= minute, =3D 1 char / second, or about 10 dot periods / =0A second.&n= bsp;   Dot speed =3D WPM / 1.2)   If we have 2s dots, =0A = that is 5 characters can be sent in the time for a WSPR =0A transm= ission.
=0A
 
=0A
So as a quick estimate, WS= PR wins by roughly 2dB in S/N terms for =0A a given dot period / no= ise bandwidth.  And at similar S/N values, WSPR =0A is about 1.5 ti= mes faster
=0A
Andy
=0A =0A <= div> 
=0A
 
=0A
 
=0A  
=0A
On 24 August 201= 1 16:42, Roger Lapthorn <rogerlapthorn@gmail.com> wrote:
=0A =
A =0A question for = the coding experts here: WSPR is an excellent weak signal =0A beaconin= g mode, but at what QRSS speed is QRSS "better" =0A ?

73s
Ro= ger G3XBM

--
http://g3x= bm-qrp.blogspot.com/
http://www.g3xbm.co.uk
=0Ahttp://www.y= outube.com/user/g3xbm
https://sites.google.com/site/sub9k= hz/

=0A



<= /blockquote>

=0A
=


--
http://g3xbm-qrp.blogspot.com/
<= a rel=3D"nofollow" target=3D"_blank" href=3D"http://www.g3xbm.co.uk">http:/= /www.g3xbm.co.uk
=0Ahttp://www.youtube.com/user/g3xbm
<= a rel=3D"nofollow" target=3D"_blank" href=3D"https://sites.google.com/site/= sub9khz/">https://sites.google.com/site/sub9khz/

=0A

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