Return-Path: Received: from mtain-dh04.r1000.mx.aol.com (mtain-dh04.r1000.mx.aol.com [172.29.65.24]) by air-ma07.mail.aol.com (v126.13) with ESMTP id MAILINMA073-b52e4b4a306432a; Sun, 10 Jan 2010 14:54:12 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-dh04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 3457C3800012C; Sun, 10 Jan 2010 14:54:11 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NU3qv-0004Zt-2w for rs_out_1@blacksheep.org; Sun, 10 Jan 2010 19:53:33 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NU3qu-0004Zk-Eb for rsgb_lf_group@blacksheep.org; Sun, 10 Jan 2010 19:53:32 +0000 Received: from mail-bw0-f221.google.com ([209.85.218.221]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NU3qr-0004EC-Ic for rsgb_lf_group@blacksheep.org; Sun, 10 Jan 2010 19:53:32 +0000 Received: by bwz21 with SMTP id 21so13501394bwz.4 for ; Sun, 10 Jan 2010 11:53:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=2M4ICwTsglGcerIVLYckh/2p8O5lM7RamqNXa3Tdgek=; b=CaXUsSmJSX4Kkj9oySBxcGrXHH972U+Y23nqbY6UYMLp+oY0ZHjgnnfM81ag1ORj7n VYw9gMzY15gAwjdI9OIdQB7UZcyW1tkWVIUEOuWrR7MCyMloHF7OSZ0SKN6P5xafM2bI qJBI5iq3vGcNB2yvRUzkS7tHTOoLY4hjZJn3U= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=jHZFrduFE/RP7n7ZYyP5bw4CWns/H+QfWCqfAjl4AlGJMwn4UNJtJKw/lZkcXC0M3Z zNXk8D2aJKCoqSZmFZMqOAqGs/K3qFfd2ANJgCZ6vlR2yWQ1KdGnNOJQ8gHp4S1ngeH7 hePiBF2CH9WlhTf/z6G5ygGJdILxI0sHrj+bE= MIME-Version: 1.0 Received: by 10.204.32.137 with SMTP id c9mr99975bkd.44.1263153203354; Sun, 10 Jan 2010 11:53:23 -0800 (PST) In-Reply-To: <004101ca922b$214cf0e0$0401a8c0@xphd97xgq27nyf> References: <000e01ca9223$6d16ec90$0517aac0@desktop> <9afca2641001101102r6252b153lf6d911ee622589e5@mail.gmail.com> <004101ca922b$214cf0e0$0401a8c0@xphd97xgq27nyf> Date: Sun, 10 Jan 2010 19:53:23 +0000 Message-ID: <9afca2641001101153u288ebc3dh81ba03efc09b650@mail.gmail.com> From: Roger Lapthorn To: rsgb_lf_group@blacksheep.org X-Karma: unknown: DomainKey-Status: good (testing) 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=0003255539c6fb9cd0047cd4c573 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.7 required=5.0 tests=HTML_40_50, 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: 3039ac1d41184b4a30633748 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --0003255539c6fb9cd0047cd4c573 Content-Type: text/plain; charset=ISO-8859-1 Fair comment Mal, and one of these days I'll try QRS and see how it performs. It should be possible to get a pretty good idea of the theoretical range limit for WSPR on 500kHz based on required S/N (which can be as low as -30dB for WSPR), path loss calculations, ERP etc.. I shall be interested to see what "the experts" say. 73s Roger G3XBM 2010/1/10 mal hamilton > Had u been on QRS CW he probably would have copied u since he saw ur > trace. I often see traces that do not decode for some time but had the trace > been keyed it could have been identified. > I have been making this point for some time, avoid guesswork and > speculation and use normal CW or QRS CW > Regardless of erp transmitted the weakness is often at the RX end Little > antenna Little signal Big antenna Big signal and environment regarding > noise. > RX loop antennas not optimised towards ur stn, these situations cannot be > calculated just guessed and meaningless. > Get into QSO mode and see how far u can get in real time. > > G3KEV > > > ----- Original Message ----- > *From:* Roger Lapthorn > *To:* rsgb_lf_group@blacksheep.org > *Sent:* Sunday, January 10, 2010 7:02 PM > *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 > > -- http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/G3XBM G3XBM GQRP 1678 ISWL G11088 --0003255539c6fb9cd0047cd4c573 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Fair comment Mal, and one of these days I'll try QRS and see how it pe= rforms.

It should be possible to get a pretty good idea of the the= oretical range limit for WSPR on 500kHz based on required S/N (which can= be as low as -30dB for WSPR), path loss calculations, ERP etc.. I shall= be interested to see what "the experts" say.

73s
Roger G3XBM



2010/1/1= 0 mal hamilton <g3kevmal@talktalk.net>
Had u been on QRS CW he probably woul= d have copied=20 u since he saw ur trace. I often see traces that do not decode for some ti= me but=20 had the trace been keyed it could have been identified.
I have been making this point for som= e time, avoid=20 guesswork and speculation and use normal=A0CW or QRS CW
Regardless of erp transmitted the wea= kness is often=20 at the RX end Little antenna Little signal Big antenna Big signal and=20 environment regarding noise.
RX loop antennas not optimised toward= s ur stn,=20 these situations cannot be calculated just guessed and meaningless.=
Get into QSO mode and see how far u= can get in real=20 time.
=A0
G3KEV
=A0
----- Original Message -----
Sent:= Sunday, January 10, 2010 7:02=20 PM
Subject: Re: LF: Link budget ca= lculation=20 or estimation of dist for given power on WSPR

Certainly GM4SLV= has a much lower noise floor than most=20 stations on 500kHz Jim. I think he estimated about 10dB lower, so it may= be=20 easier for him to hear very weak signals than many others.

For wh= at=20 it's worth, my 1mW ERP has been received at -18dB S/N at 990kms rang= e in=20 S.Germany (and at around -23dB a few times), so assuming another 10-12dB= in=20 hand, that must be good for another skywave "hop" under favour= able conditions.=20 I am still hopeful that TF3HZ might just spot me on a good night. The ma= gic=20 1000kms barrier is tantalisingly close. RN3AGC says he might just have= seen a=20 "whisper" of a trace from me the other night and he is 2400kms= away, but if it=20 was me it was far too weak to decode.

It will be interesting to= see=20 what people say is possible based on the propagation theory=20 etc.

73s
Roger G3XBM

2010/1/10 James Cowburn <= ;james.cowbu= rn@virgin.net>

=A0Dear LF,

Has anyone any ideas or suggestions on a resou= rce=20 for calculation of a link budget for WSPR over a set=20 distance?

As it seems I can get up to GM4SLV reasonably= =20 consistently on my current antenna/power setting with a SNR of around= -22dB=20 and the limit for WSPR is around -30dB then is there a means for rough= ly=20 estimating or indeed accurately calculating the Expected Max Range (EM= R) at=20 that power setting and antenna configuration?

Clearly, there are differences between separat= e Rx=20 stations but if one knows the ratio between two or more Rx stations th= en it=20 should be possible to pro-rate or estimate at least the signal strengt= h at a=20 given Rx based on its performance with other known=20 signals.

If I can do 916km with an SNR of say -22dB the= n how=20 much further would the remaining =A08dB or so of WSPR detection get me= ,=20 assuming the other Rx has the same capability as GM4SLV and if their= =20 capability is different, then is it fine to factor for the dB differen= ce=20 over known paths/signals?

Thanks in advance for any answers or pointers= and=20 best wishes to all for a great 2010

= With bes= t=20 regards

= =A0

= =A0

Jim

= =A0

= =A0

= Dr. Jame= s Cowburn=20 G7NKS

= E=20 james.cowburn@virgin= .net<= /font>

=A0

=A0

=



--

http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.u= k
h= ttp://www.youtube.com/user/G3XBM
G3XBM=20 =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL=20 G11088



--

http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/G3XBM
G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088
--0003255539c6fb9cd0047cd4c573--