Return-Path: Received: from rly-da02.mx.aol.com (rly-da02.mail.aol.com [172.19.129.76]) by air-da10.mail.aol.com (v125.7) with ESMTP id MAILINDA103-a564aed6986361; Sun, 01 Nov 2009 05:57:18 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-da02.mx.aol.com (v125.7) with ESMTP id MAILRELAYINDA026-a564aed6986361; Sun, 01 Nov 2009 05:57:12 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1N4Y6k-0003aV-RE for rs_out_1@blacksheep.org; Sun, 01 Nov 2009 10:56:26 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1N4Y6k-0003aM-Bw for rsgb_lf_group@blacksheep.org; Sun, 01 Nov 2009 10:56:26 +0000 Received: from fg-out-1718.google.com ([72.14.220.155]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1N4Y4y-0003HS-GS for rsgb_lf_group@blacksheep.org; Sun, 01 Nov 2009 10:54:37 +0000 Received: by fg-out-1718.google.com with SMTP id d23so655501fga.10 for ; Sun, 01 Nov 2009 02:56:11 -0800 (PST) MIME-Version: 1.0 Received: by 10.239.130.35 with SMTP id 35mr399668hbh.31.1257072971528; Sun, 01 Nov 2009 02:56:11 -0800 (PST) X-Originating-IP: [78.86.215.152] In-Reply-To: <9afca2640910311126k1aa9fdf2maafb546bbf89d372@mail.gmail.com> References: <9afca2640910310528p4f07557aifdc0557a68bfeff8@mail.gmail.com> <004501ca5a35$30eff840$0900a8c0@lark> <9afca2640910311126k1aa9fdf2maafb546bbf89d372@mail.gmail.com> Date: Sun, 1 Nov 2009 10:56:11 +0000 Message-ID: From: PETER CLEALL To: rsgb_lf_group@blacksheep.org X-Karma: unknown: X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Re: 500kHz attenuation graphs? Content-Type: multipart/alternative; boundary=001485f6d900ecbc3804774d1b09 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,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-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --001485f6d900ecbc3804774d1b09 Content-Type: text/plain; charset=ISO-8859-1 below are my rather vague memories, I am sure I have it archived on CD somewhere, but will not have access for several weeks. The information may still be on the web but had a quick look and could not see it. Maybe contacting Geri direct will help. Geri DK8KW used to have some useful charts from the time when he was trying to justify an increase in power for the German allocation. The basic curve on the chart was the equivalent of the CCIR information.Then he had the strengths of numerous European signals regards peter G8AFN 2009/10/31 Roger Lapthorn > Thanks Alan. > > I have downloaded the GRNDWAV3 programme and am playing with it - looks > useful. > > Really looking for some *normalised curves* so I could do very quick > estimates of expected losses versus distance. I've seen these years ago in a > CCIR paperback and was hoping to find these on the net somewhere. > > Now back to 500kHz WSPRing.... > > 73s > Roger G3XBM > > 2009/10/31 Alan Melia > > Hi Roger you will find that the late Reg Edwards programs GRNDWAV3 (I >> think) >> gives a very good idea of ground wave strengths. I do have an article here >> (somewhere) from Jack Belrose with I believe some skywave strength formula >> in it. (I am "between two PCs" at the moment :-)) and it is undoubtedly on >> the other one ) Generally at LF the skywave starts to equal or exceed the >> groundwave strength at ranges exceeding 700km. It may be a little less >> that >> that at 500k. It also depends a little on the receive-system senitivity to >> a >> given mode, which is why very low power stations sometimes experience a >> "quiet zone" at least to audible reception. >> >> Alan G3NYK >> >> >> >> >> >> ----- Original Message ----- >> From: "Roger Lapthorn" >> To: >> Sent: Saturday, October 31, 2009 12:28 PM >> Subject: LF: 500kHz attenuation graphs? >> >> >> > Can someone please point me to any CCIR or similar graphs (preferably on >> the >> > internet) showing the attenuation with distance expected on groundwave >> and >> > skywave at 500kHz? >> > >> > 73s >> > Roger G3XBM >> > >> > -- >> > ------------------------------------------------------------- >> > http://g3xbm-qrp.blogspot.com/ >> > http://www.g3xbm.co.uk >> > G3XBM GQRP 1678 ISWL G11088 >> > >> >> >> > > > -- > ------------------------------------------------------------- > http://g3xbm-qrp.blogspot.com/ > http://www.g3xbm.co.uk > G3XBM GQRP 1678 ISWL G11088 > --001485f6d900ecbc3804774d1b09 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
below are my rather vague memories, I am sure I have it archived on= CD somewhere, but will not have access for several weeks. The information= may still be on the web but =A0had a quick look and could not see it. May= be contacting Geri direct will help.


Geri DK8KW used to have some useful cha= rts from the time when he was trying to justify an increase in power for= the German allocation. The basic curve on the chart was the equivalent of= the CCIR information.Then he had the strengths of numerous European signa= ls

regards
peter G8AFN




2009/10/31= Roger Lapthorn <rogerlapthorn@gmail.com>
Thanks Alan.

I have downloaded th= e GRNDWAV3 programme and am playing with it - looks useful.

Really= looking for some normalised curves so I could do very quick estima= tes of expected losses versus distance. I've seen these years ago in= a CCIR paperback and was hoping to find these on the net somewhere.

Now back to 500kHz WSPRing....

73s
Roger G3XBM

2009/10/31 Alan Melia <alan.melia@btinter= net.com>

Hi Roger you will fi= nd that the late Reg Edwards programs GRNDWAV3 (I think)
gives a very good idea of ground wave strengths. I do have an article here=
(somewhere) from Jack Belrose with I believe some skywave strength formula=
in it. (I am "between two PCs" at the moment :-)) and it is undo= ubtedly on
the other one ) Generally at LF the skywave starts to equal or exceed the<= br> groundwave strength at ranges exceeding 700km. It may be a little less tha= t
that at 500k. It also depends a little on the receive-system senitivity to= a
given mode, which is why very low power stations sometimes experience a "quiet zone" at least to audible reception.

Alan G3NYK





----- Original Message -----
From: "Roger Lapthorn" <rogerlapthorn@gmail.com>
To: <= rsgb_lf_group@blacksheep.org>
Sent: Saturday, October 31, 2009 12:28 PM
Subject: LF: 500kHz attenuation graphs?


> Can someone please point me to any CCIR or similar graphs (preferably= on
the
> internet) showing the attenuation with distance expected on groundwav= e and
> skywave at 500kHz?
>
> 73s
> Roger G3XBM
>
> --
> -------------------------------------------------------------
> http://g= 3xbm-qrp.blogspot.com/
> http://www.g3xbm= .co.uk
> G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088
>





--
------------------------------------------------------------= -
http://g= 3xbm-qrp.blogspot.com/
http://www.g3xbm.co.u= k
G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088

--001485f6d900ecbc3804774d1b09--