Return-Path: Received: from mtain-mg03.r1000.mx.aol.com (mtain-mg03.r1000.mx.aol.com [172.29.96.203]) by air-dc06.mail.aol.com (v129.10) with ESMTP id MAILINDC064-86a44db8873425; Wed, 27 Apr 2011 17:14:28 -0400 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mg03.r1000.mx.aol.com (Internet Inbound) with ESMTP id 845DA38000086; Wed, 27 Apr 2011 17:14:25 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QFC3M-0000YG-JQ for rs_out_1@blacksheep.org; Wed, 27 Apr 2011 22:13:44 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QFC3L-0000Y5-Ug for rsgb_lf_group@blacksheep.org; Wed, 27 Apr 2011 22:13:43 +0100 Received: from imr-mb01.mx.aol.com ([64.12.207.164]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1QFC3I-0007HX-NA for rsgb_lf_group@blacksheep.org; Wed, 27 Apr 2011 22:13:43 +0100 Received: from mtaout-mb02.r1000.mx.aol.com (mtaout-mb02.r1000.mx.aol.com [172.29.41.66]) by imr-mb01.mx.aol.com (8.14.1/8.14.1) with ESMTP id p3RLDMnR005869 for ; Wed, 27 Apr 2011 17:13:22 -0400 Received: from White (nrbg-4d0726fa.pool.mediaWays.net [77.7.38.250]) by mtaout-mb02.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 44F1AE0000CD for ; Wed, 27 Apr 2011 17:13:19 -0400 (EDT) Message-ID: <941E9447D53D4D9794138E70C20EF61C@White> From: "Markus Vester" To: References: <4DB8535B.7040903@talktalk.net><4DB873DB.500@talktalk.net> Date: Wed, 27 Apr 2011 23:13:54 +0200 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 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: More 8.97kHz WSPR decodes - changed PC here Content-Type: multipart/alternative; boundary="----=_NextPart_000_000A_01CC0530.C7248450" 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_MESSAGE, LINES_OF_YELLING,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: 3039ac1d60cb4db887314e7e X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none ------=_NextPart_000_000A_01CC0530.C7248450 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Roger, WSPR should decode from about -29 dB SNR in 2.5 kHz (ie. 0 dB in 3.2= Hz). On the other hand, a clearly discernible carrier in a 0.42 mHz= FFT ("DFCW-6000") would require about 6 dB SNR in the 0.63 mHz noise= bandwidth (ie. 0 dB in 2.5 mHz).=20 The difference in sensitivity would thus be around 31 dB. Of course th= e data rate will be different as well... Best 73, Markus From: Roger Lapthorn=20 Sent: Wednesday, April 27, 2011 10:45 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: More 8.97kHz WSPR decodes - changed PC here Dear Eddie (et al) In the context of the very very weak signals experienced at VLF I don'= t think WSPR is a serious contender except for localised tests. No dou= bt someone here far more knowledgeable than me can tell us the "dB adv= antage" of say, QRSS600 or 6000 versus WSPR, but the difference must= be enormous.=20 Where WSPR scores, in my view, is the automatic reporting via the inte= rnet database. This has proved a real boon at 137 and 500kHz. Even her= e though very slow QRSS would beat WSPR every time. I am a great beli= ever in WSPR, but do not believe it will be that much use at VLF. Andy (G4JNT) are you able to comment on please? 73s Roger G3XBM On 27 April 2011 20:51, qrss wrote: Just a further thought. WSPR doesn't of course spread its power over= 6Hz it actually transmits full carrier on each of the four frequencie= s for 0.682 mS and sometimes several of the same element follow withou= t a break in carrier, which accounts for some of the bright spots and= lines we see when things are marginal. One element is a longer dot ti= me than 2WPM Morse, and that is SLOW Morse. Long integration times are out of course. 73 Eddie G3ZJO =20 On 27/04/2011 18:58, Roger Lapthorn wrote:=20 Hi Eddie (et al) It is highly unlikely you'd copy Andrew on VLF remembering that th= e WSPR signal spreads around 6Hz in the transmission burst, so the ene= rgy in any narrow FFT bin would be tiny. Also, this is earth mode (I= hope, as G6ALB does not hold an NoV to radiate at VLF), so signals ar= e propagating through the ground by conduction and no significant amou= nt of signal is radiated.=20 I'm still intrigued why the best reception here today was with my= 80sq m vertical loop. This outperformed several earth electrode set-u= ps here at the RX end, an E-field probe and a 30t loop laying close to= copper pipe work in the house! If the signals are coming down the pi= pes then why don't these more direct means of coupling to them work as= well as (or better than) a vertical loop outside? Odd. 73s Roger G3XBM On 27 April 2011 18:33, qrss wrote: Great stuff Roger and Andrew If you are RX'ing on an 80m dipole it may be worth a look here,= I would never say can't until I have tried. Bearing in mind I should= be able to observe signals which would not be decode able on WSPR I would appreciate a prior notification of times and exact frequ= ency of the WSPR signal of any further tests. Keep it up. 73 Eddie G3ZJO=20 On 27/04/2011 15:19, Roger Lapthorn wrote: As an experiment I changed over to my wife's laptop and got im= mediate decodes of G6ALB's VLF earth mode signal (3km) at -17dB S/N,= suggesting the issue with lack of decodes may be with my soundcard an= d not Andrew's. 1408 -17 -0.6 0.008986 0 G6ALB JO02 47 1410 -17 -0.6 0.008986 0 G6ALB JO02 47 1412 -17 -1.2 0.008986 0 G6ALB JO02 47 1414 -17 -0.8 0.008986 0 G6ALB JO02 47 1416 -17 -0.8 0.008986 0 G6ALB JO02 47 This is a very solid signal on the 80m square single turn vert= ical wire loop antenna. Andrew is using 44W to an earth electrode ante= nna. 73s Roger G3XBM --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm https://sites.google.com/site/sub9khz/ --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm https://sites.google.com/site/sub9khz/ --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm https://sites.google.com/site/sub9khz/ ------=_NextPart_000_000A_01CC0530.C7248450 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Roger,
 
WSPR should decode from about -29 dB= SNR in 2.5 kHz=20 (ie. 0 dB in 3.2 Hz). On the other hand, a=20 clearly discernible carrier in a 0.42 mHz FFT ("DFCW-6000") = would=20 require about 6 dB SNR in the 0.63 mHz noise bandwidth (ie. 0 dB= in 2.5=20 mHz).
 
The difference in sensitivity would= thus be around=20 31 dB. Of course the data rate will be different as=20 well...
 
Best 73,
Markus

Sent: Wednesday, April 27, 2011 10:45 PM
Subject: Re: LF: More 8.97kHz WSPR decodes - changed PC=20 here

Dear Eddie (et al)

In the context of the very= very=20 weak signals experienced at VLF I don't think WSPR is a serious conten= der except=20 for localised tests. No doubt someone here far more knowledgeable than= me can=20 tell us the "dB advantage" of say, QRSS600 or 6000 versus WSPR, but th= e=20 difference must be enormous.

Where WSPR scores, in my view, is= the=20 automatic reporting via the internet database. This has proved a real= boon at=20 137 and 500kHz. Even here though very slow QRSS would beat WSPR every= =20 time.  I am a great believer in WSPR, but do not believe it will= be that=20 much use at VLF.

Andy (G4JNT) are you able to comment on=20 please?

73s
Roger G3XBM




On 27 April 2011 20:51, qrss = <qrss@talktalk.net> wrote:
Just a further thought. WS= PR doesn't of=20 course spread its power over 6Hz it actually transmits full carrier= on each of=20 the four frequencies for 0.682 mS and sometimes several of the same= element=20 follow without a break in carrier, which accounts for some of the br= ight spots=20 and lines we see when things are marginal. One element is a longer= dot time=20 than 2WPM Morse, and that is SLOW Morse.
Long integration times= are out of=20 course.

73 Eddie G3ZJO
 =20

On 27/04/2011 18:58, Roger Lapthorn wrote:
Hi Eddie (et al)

It is highly unlik= ely you'd=20 copy Andrew on VLF remembering that the WSPR signal spreads around= 6Hz in=20 the transmission burst, so the energy in any narrow FFT bin would= be tiny.=20 Also, this is earth mode (I hope, as G6ALB does not hold an NoV to= radiate=20 at VLF), so signals are propagating through the ground by conducti= on and no=20 significant amount of signal is radiated.

I'm still intrig= ued why=20 the best reception here today was with my 80sq m vertical loop. Th= is=20 outperformed several earth electrode set-ups here at the RX end,= an E-field=20 probe and a 30t loop laying close to copper pipe work in the house= !  If=20 the signals are coming down the pipes then why don't these more di= rect means=20 of coupling to them work as well as (or better than) a vertical lo= op=20 outside? Odd.

73s
Roger G3XBM



On 27 April 2011 18:33, qrss <qrss@talktalk.net> wrote:
G= reat=20 stuff Roger and Andrew

If you are RX'ing on an 80m dipole= it may be=20 worth a look here, I would never say can't until I have tried.= Bearing in=20 mind I should be able to observe signals which would not be deco= de able on=20 WSPR

I would appreciate a prior notification of times and= exact=20 frequency of the WSPR signal of any further tests.

Keep= it=20 up.

73 Eddie G3ZJO=20


On 27/04/2011 15:19, Roger Lapthorn wrote:
As=20 an experiment I changed over to my wife's laptop and got immed= iate=20 decodes of G6ALB's VLF earth mode signal (3km) at -17dB S/N,= suggesting=20 the issue with lack of decodes may be with my soundcard and no= t=20 Andrew's.

1408 -17 -0.6   0.008986  0 G6ALB= JO02=20 47
1410 -17 -0.6   0.008986  0 G6ALB JO02 47
1= 412 -17=20 -1.2   0.008986  0 G6ALB JO02 47
1414 -17 -0.8 &n= bsp;=20 0.008986  0 G6ALB JO02 47
1416 -17 -0.8   0.00898= 6  0=20 G6ALB JO02 47

This is a very solid signal on the 80m sq= uare=20 single turn vertical wire loop antenna. Andrew is using 44W to= an earth=20 electrode antenna.

73s
Roger G3XBM

--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm
https://sites.google.com/site/sub9khz/





--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://= www.youtube.com/user/g3xbm
https://sites.google.com/si= te/sub9khz/





--
http://g3xbm-qrp.blogspot.com/
<= A href=3D"http://www.g3xbm.co.uk" target=3D_blank>http://www.g3xbm.c= o.uk
http://www.youtube.com/user/g3xbm
https://sites.goog= le.com/site/sub9khz/

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