Return-Path: Received: from mtain-df03.r1000.mx.aol.com (mtain-df03.r1000.mx.aol.com [172.29.64.215]) by air-mc06.mail.aol.com (v129.4) with ESMTP id MAILINMC062-a9744d6ffce61fb; Thu, 03 Mar 2011 15:41:10 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-df03.r1000.mx.aol.com (Internet Inbound) with ESMTP id A2911380000A4; Thu, 3 Mar 2011 15:41:09 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PvFJt-0007ju-Bb for rs_out_1@blacksheep.org; Thu, 03 Mar 2011 20:40:21 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PvFJs-0007jl-S6 for rsgb_lf_group@blacksheep.org; Thu, 03 Mar 2011 20:40:20 +0000 Received: from mail-iy0-f171.google.com ([209.85.210.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PvFJq-0004Jr-FS for rsgb_lf_group@blacksheep.org; Thu, 03 Mar 2011 20:40:20 +0000 Received: by iyf40 with SMTP id 40so1811046iyf.16 for ; Thu, 03 Mar 2011 12:40:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=4IGmnnaAzE87ftsAZNGdgzlmWOEPSOyvD2NZsW10va4=; b=Nx7GwCmqK52u/W4E5zK/Md+3nHcaLRlTN3dcH34jsLi6y2ulUL3Lq/n5CiCsA4LXep DN4gKRVIlZal5GsgcR/IYRHaGUt4V4hmfKGEkLgCiVLFqWtwV8EIeheFtIw+bGDXMFtJ ADBkCkVnPzVXG5uvlBioCROS2uCLZF777Ei8Y= 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=KksRjdL+3Kliizn3RPR0ZXh+D6wJto6xTEszC8TDz/6OPigzU9wbA+8OjDcrK7VT3A 12WC+wr1FpVPp7GUx7ekRH5LC97oMOjgjHrVEI2WRzP4OwTfu1Sp51orgI/8lDbOvTdC /NCd0jfmA7vMmMhJir4DnIEaoaoNjLW0HmZsM= MIME-Version: 1.0 Received: by 10.42.226.66 with SMTP id iv2mr2198413icb.133.1299184811612; Thu, 03 Mar 2011 12:40:11 -0800 (PST) Received: by 10.231.199.197 with HTTP; Thu, 3 Mar 2011 12:40:11 -0800 (PST) In-Reply-To: References: <6C9E0C3D501744C99E11539B7AFCB120@IBM7FFA209F07C> Date: Thu, 3 Mar 2011 20:40:11 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Topband Test Content-Type: multipart/alternative; boundary=20cf3054a03731a67a049d9a09ef X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,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-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d271.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d40d74d6ffce569a1 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) --20cf3054a03731a67a049d9a09ef Content-Type: text/plain; charset=ISO-8859-1 No, it definitely is due to ionospheric shift. 30m/s is no big deal over the period of the day/night transition. 30 minutes at that speed would be a mean change in height of 54km. Not unrealistic for an E layer (??) height of 120km Try to find a copy of G3PLX's article 'JNT On 3 March 2011 20:19, Markus Vester wrote: > Hi Chris, thanks for sharing this unusual observation. > > From your screenshot, the split was up to about 0.35 Hz, or 0.2 ppm of 1.8 > MHz. Interpreted as Doppler, a reflector would have to move at least 30m/s > radially from your baseline. This seems a bit fast for an > ionospheric day-to-night shift. > > Another possible explanation could be airplane scatter. Large airliners are > known to have a large radar cross section at HF. Seeing that on 160 m may > seem extreme, but considering the wingspan of an A-380 (80 m), half-wave > resonant scattering is a very real possibility. The downward slope of > the Doppler shifted frequency would also be indicative of an object passing > by at constant linear velocity. > > Best 73, > Markus (DF6NM) > > *From:* Chris > *Sent:* Thursday, March 03, 2011 7:55 PM > *To:* RSGB LF Group > *Subject:* LF: Topband Test > > Hi All, > Yesterday evening Pete, M0FMT, transmitted QRSS on topband for a test. An > unexpected effect was noticed with the trace splitting in two. Nothing new > or 'earth shattering' I expect, but new to us and worthy of further > experimentation. > See the result and conclusion on my website http://qsl.net/g4ayt on the > bottom of page 1. > I have never seen this effect on 137, even with quite strong audible > signals, maybe others have. > Vy 73, > Chris, G4AYT, Whitstable, UK. > --20cf3054a03731a67a049d9a09ef Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
No, it=A0definitely is due to=A0ionospheric shift.=A0=A0 30m/s is no= big deal over the=A0period of the=A0day/night transition.=A0 30 minutes= at that speed would be a mean change in height=A0of 54km.=A0=A0 Not =A0un= realistic for an=A0E layer (??) height of 120km
=A0
Try to find a copy of G3PLX's article
=A0
'JNT


=A0
On 3 March 2011 20:19, Markus Vester <markusvester@aol.com<= /a>> wrote:
Hi Chris, thanks for sharing this unu= sual observation.
=A0
From your screenshot, the split was= up to about 0.35 Hz, or 0.2 ppm of 1.8 MHz.=A0Interpreted as Doppler,=A0a= reflector would have to move at least 30m/s radially from your baseline.= =A0This seems a bit fast for=A0an ionospheric=A0day-to-night shift.=
=A0
Another possible explanation could be= airplane scatter. Large airliners=A0are known to have a large=A0radar cro= ss section at HF.=A0Seeing that on 160 m may seem extreme, but=A0consideri= ng the wingspan of an A-380=A0(80 m),=A0half-wave resonant scattering is= a very real possibility.=A0The downward slope=A0of the=A0Doppler shifted= frequency would also be indicative=A0of an object passing by=A0at constan= t linear velocity.
=A0
Best 73,
Markus (DF6NM)

Sent: Thursday, March 03, 2011 7:55 PM
Subject: LF: Topband Test

Hi All,
Yesterday evening Pete, M0FMT, transm= itted QRSS on topband for a test. An unexpected effect was noticed with th= e trace splitting in two. Nothing new or 'earth shattering' I expe= ct, but new to us and worthy of further experimentation.
See the result and conclusion on my= website http://qsl.net= /g4ayt on the bottom of page 1.
I have never seen this effect on 137,= even with quite strong audible signals, maybe others have.
Vy 73,
Chris, G4AYT, Whitstable, UK.<= /div>

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