Return-Path: Received: from rly-df07.mx.aol.com (rly-df07.mail.aol.com [172.19.156.20]) by air-df01.mail.aol.com (v125.7) with ESMTP id MAILINDF011-5614aec8189359; Sat, 31 Oct 2009 14:27:43 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-df07.mx.aol.com (v125.7) with ESMTP id MAILRELAYINDF072-5614aec8189359; Sat, 31 Oct 2009 14:27:22 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1N4Iet-00063Z-Lu for rs_out_1@blacksheep.org; Sat, 31 Oct 2009 18:26:39 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1N4Iet-00063Q-2x for rsgb_lf_group@blacksheep.org; Sat, 31 Oct 2009 18:26:39 +0000 Received: from mail-bw0-f221.google.com ([209.85.218.221]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1N4Id7-0007WP-Eh for rsgb_lf_group@blacksheep.org; Sat, 31 Oct 2009 18:24:50 +0000 Received: by bwz21 with SMTP id 21so4883077bwz.4 for ; Sat, 31 Oct 2009 11:26:18 -0700 (PDT) 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=0LXtGdSnCohtdEctRg5gnWCNhfuTnNbUa4JCwr2c+84=; b=fevnGuc/VhcJcKm1TcMsno8qE3YRPhI5MpFze+v8HktUH3wqu51R0/6gZJT1Gv3+Nf 1CNKWA44l7xIUX70WuOWVw/OQFTErwAtv4nLDumgZLyM77gVhveD4usJ4LAqGM6MzCs4 C6vFAsb7oe3JjnRLj0OtcK7prEGjeC8aSAPuU= 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=KMzAyQ/G9f5sPDYzkjacutzZuUpRrE3+ZmK4BXFqPfHTba9kiesMgGCaXOd2TtNfOR TCMdxKBPsfyhSvv4+Zn2V43FDZ+CWT6VNdmautcLyTjfKRT/1gPlONzvqFKPBfV9zpD/ rqhkNr+23rVRvgW4tzzEJn8Wc6FuweQXNC9qo= MIME-Version: 1.0 Received: by 10.204.141.18 with SMTP id k18mr2275953bku.139.1257013578613; Sat, 31 Oct 2009 11:26:18 -0700 (PDT) In-Reply-To: <004501ca5a35$30eff840$0900a8c0@lark> References: <9afca2640910310528p4f07557aifdc0557a68bfeff8@mail.gmail.com> <004501ca5a35$30eff840$0900a8c0@lark> Date: Sat, 31 Oct 2009 18:26:18 +0000 Message-ID: <9afca2640910311126k1aa9fdf2maafb546bbf89d372@mail.gmail.com> From: Roger Lapthorn To: rsgb_lf_group@blacksheep.org X-Karma: unknown: DomainKey-Status: good (testing) 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=0015175cb728d4c28904773f47dd X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=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-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d261.1 ; domain : gmail.com DKIM : pass X-Mailer: Unknown (No Version) --0015175cb728d4c28904773f47dd Content-Type: text/plain; charset=ISO-8859-1 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 --0015175cb728d4c28904773f47dd Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thanks Alan.

I have downloaded the GRNDWAV3 programme and am playi= ng 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 hopin= g to find these on the net somewhere.

Now back to 500kHz WSPRing....

73s
Roger G3XBM

2009/10/31 Alan Melia <alan.melia@btinternet.com>
Hi Roger you wi= ll 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 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@blac= ksheep.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://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088
--0015175cb728d4c28904773f47dd--