Return-Path: Received: from mtain-md08.r1000.mx.aol.com (mtain-md08.r1000.mx.aol.com [172.29.96.92]) by air-dc09.mail.aol.com (v126.13) with ESMTP id MAILINDC092-862d4b4a2923294; Sun, 10 Jan 2010 14:23:15 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-md08.r1000.mx.aol.com (Internet Inbound) with ESMTP id 55B653800036B; Sun, 10 Jan 2010 14:23:13 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NU3MY-0004E3-Po for rs_out_1@blacksheep.org; Sun, 10 Jan 2010 19:22:10 +0000 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NU3MX-0004Du-VX for rsgb_lf_group@blacksheep.org; Sun, 10 Jan 2010 19:22:10 +0000 Received: from mtaout01-winn.ispmail.ntl.com ([81.103.221.47]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NU3MT-0000SO-SH for rsgb_lf_group@blacksheep.org; Sun, 10 Jan 2010 19:22:09 +0000 Received: from know-smtpout-2.server.virginmedia.net ([62.254.123.2]) by mtaout01-winn.ispmail.ntl.com (InterMail vM.7.08.04.00 201-2186-134-20080326) with ESMTP id <20100110192200.UGDP17029.mtaout01-winn.ispmail.ntl.com@know-smtpout-2.server.virginmedia.net> for ; Sun, 10 Jan 2010 19:22:00 +0000 Received: from [86.26.81.210] (helo=desktop) by know-smtpout-2.server.virginmedia.net with esmtp (Exim 4.63) (envelope-from ) id 1NU3MM-0003PN-RK for rsgb_lf_group@blacksheep.org; Sun, 10 Jan 2010 19:22:00 +0000 From: "James Cowburn" To: References: <000e01ca9223$6d16ec90$0517aac0@desktop> <9afca2641001101102r6252b153lf6d911ee622589e5@mail.gmail.com> Date: Sun, 10 Jan 2010 19:21:54 -0000 Message-ID: <001901ca922a$2b2335d0$0517aac0@desktop> MIME-Version: 1.0 X-Mailer: Microsoft Office Outlook 11 In-Reply-To: <9afca2641001101102r6252b153lf6d911ee622589e5@mail.gmail.com> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 Thread-Index: AcqSJ6Ck1kwpKrcxSvqER4vT56GAiAAAdi8g X-Cloudmark-Analysis: v=1.1 cv=ZtHxNT4mZm3rCuM0SmWmgWxeBwJsziC8EqOrwwVkrhA= c=1 sm=0 a=8Qw2kvqKHfsA:10 a=F3M5lZpKAAAA:8 a=8RloEfZUAAAA:8 a=fnYqA7hvAAAA:8 a=j6Q1dnSHAAAA:8 a=A06HpNCPAAAA:20 a=EzDJ2dT560G0u8GKkLcA:9 a=mG-MdoWuzAy6tc1G8mMA:7 a=8PHFf5G4JcB7m7YUDM53aZmu2TgA:4 a=wk6s2zzMB60A:10 a=O58u2wXj750A:10 a=gA6IeH5FQcgA:10 a=NWVoK91CQyQA:10 a=GJhCsiFwJrh6W7XF:21 a=KQpVIqDFqN8_AQJ6:21 a=SSmOFEACAAAA:8 a=8abNOscc_tovgz8oKogA:9 a=RE0Z3X1C4QJoAI62H-MA:7 a=beryAeJMTaiiQIXooz5EgjiBFEQA:4 a=HpAAvcLHHh0Zw7uRqdWCyQ==:117 X-Spam-Score: 0.3 (/) X-Spam-Report: autolearn=disabled,HTML_FONT_BIG=0.256,HTML_MESSAGE=0.001 Subject: RE: LF: Link budget calculation or estimation of dist for given power on WSPR Content-Type: multipart/alternative; boundary="----=_NextPart_000_001A_01CA922A.2B2335D0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.4 required=5.0 tests=HTML_50_60, HTML_FONTCOLOR_UNKNOWN,HTML_FONT_BIG,HTML_MESSAGE 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: 3039ac1d605c4b4a29215819 X-AOL-IP: 193.82.116.20 ------=_NextPart_000_001A_01CA922A.2B2335D0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi Roger I have managed 1020km D?RAJ on my old Tx before it expired. TF3 would be great though. 73s Jim _____ From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Roger Lapthorn Sent: 10 January 2010 19:03 To: rsgb_lf_group@blacksheep.org Subject: Re: LF: Link budget calculation or estimation of dist for given power on WSPR Certainly GM4SLV has a much lower noise floor than most stations on 500kHz Jim. I think he estimated about 10dB lower, so it may be easier for him to hear very weak signals than many others. For what it's worth, my 1mW ERP has been received at -18dB S/N at 990kms range in S.Germany (and at around -23dB a few times), so assuming another 10-12dB in hand, that must be good for another skywave "hop" under favourable conditions. I am still hopeful that TF3HZ might just spot me on a good night. The magic 1000kms barrier is tantalisingly close. RN3AGC says he might just have seen a "whisper" of a trace from me the other night and he is 2400kms away, but if it was me it was far too weak to decode. It will be interesting to see what people say is possible based on the propagation theory etc. 73s Roger G3XBM 2010/1/10 James Cowburn Dear LF, Has anyone any ideas or suggestions on a resource for calculation of a link budget for WSPR over a set distance? As it seems I can get up to GM4SLV reasonably consistently on my current antenna/power setting with a SNR of around -22dB and the limit for WSPR is around -30dB then is there a means for roughly estimating or indeed accurately calculating the Expected Max Range (EMR) at that power setting and antenna configuration? Clearly, there are differences between separate Rx stations but if one knows the ratio between two or more Rx stations then it should be possible to pro-rate or estimate at least the signal strength at a given Rx based on its performance with other known signals. If I can do 916km with an SNR of say -22dB then how much further would the remaining 8dB or so of WSPR detection get me, assuming the other Rx has the same capability as GM4SLV and if their capability is different, then is it fine to factor for the dB difference over known paths/signals? Thanks in advance for any answers or pointers and best wishes to all for a great 2010 With best regards Jim Dr. James Cowburn G7NKS E james.cowburn@virgin.net -- http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/G3XBM G3XBM GQRP 1678 ISWL G11088 ------=_NextPart_000_001A_01CA922A.2B2335D0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Hi Roger

 

I have managed= 1020km  D?RAJ on my old Tx before it expired.   TF3 would be great though. =

 

73s<= /span>

 

Jim<= /span>

 

From: owner-rsgb_lf_group@blac= ksheep.org [mailto:owner-= rsgb_lf_group@blacksheep.org] On Behalf Of Roger Lapthorn
Sent: 10 January 2010= 19:03
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: Link= budget calculation or estimation of dist for given power on WSPR

 

Certainly GM4SL= V has a much lower noise floor than most stations on 500kHz Jim. I think he es= timated about 10dB lower, so it may be easier for him to hear very weak signal= s than many others.

For what it's worth, my 1mW ERP has been received at -18dB S/N at 990k= ms range in S.Germany (and at around -23dB a few times), so assuming another 10= -12dB in hand, that must be good for another skywave "hop" under favo= urable conditions. I am still hopeful that TF3HZ might just spot me on a good= night. The magic 1000kms barrier is tantalisingly close. RN3AGC says he might= just have seen a "whisper" of a trace from me the other night and= he is 2400kms away, but if it was me it was far too weak to decode.

It will be interesting to see what people say is possible based on the propagation theory etc.

73s
Roger G3XBM

2010/1/10 James Cowburn <james.cowburn@virgin.net>=

 Dear LF,

Has anyone any ideas or suggestions on a resource for calculation of a link budget fo= r WSPR over a set distance?

As it seems I can get up to GM4SLV reasonably consistently on my current antenna/power= setting with a SNR of around -22dB and the limit for WSPR is around -30dB then= is there a means for roughly estimating or indeed accurately calculating the Ex= pected Max Range (EMR) at that power setting and antenna configuration?<= /o:p>

Clearly, there are differences between separate Rx stations but if one knows the ratio be= tween two or more Rx stations then it should be possible to pro-rate or estimate= at least the signal strength at a given Rx based on its performance with other= known signals.

If I can do 916km with an SNR of say -22dB then how much further would the remaining &nb= sp;8dB or so of WSPR detection get me, assuming the other Rx has the same capabi= lity as GM4SLV and if their capability is different, then is it fine to factor= for the dB difference over known paths/signals?

Thanks in advance for any answers or pointers and best wishes to all for a great 2010

With best regards=

 

 

<= span style=3D'font-size:24.0pt; font-family:"Freestyle Script";color:n= avy;font-weight:bold'>Jim

 

 

Dr. James Cowburn G7NKS<= /span>

E james.cowburn@virgin.net

 

 




--

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http://www.g3xbm.co.uk
http://www.youtube.com/u= ser/G3XBM
G3XBM    GQRP 1678      ISWL G11088

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