Return-Path: Received: from mtain-ma02.r1000.mx.aol.com (mtain-ma02.r1000.mx.aol.com [172.29.96.10]) by air-md08.mail.aol.com (v129.4) with ESMTP id MAILINMD083-8b924d7000551a1; Thu, 03 Mar 2011 15:55:49 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-ma02.r1000.mx.aol.com (Internet Inbound) with ESMTP id A7EBA38000084; Thu, 3 Mar 2011 15:55:47 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PvFYC-00084e-4G for rs_out_1@blacksheep.org; Thu, 03 Mar 2011 20:55:08 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PvFYB-00084V-DU for rsgb_lf_group@blacksheep.org; Thu, 03 Mar 2011 20:55:07 +0000 Received: from nm6.bullet.mail.ukl.yahoo.com ([217.146.182.227]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1PvFY9-0004aa-Vj for rsgb_lf_group@blacksheep.org; Thu, 03 Mar 2011 20:55:07 +0000 Received: from [217.146.183.209] by nm6.bullet.mail.ukl.yahoo.com with NNFMP; 03 Mar 2011 20:55:00 -0000 Received: from [217.146.183.177] by tm2.bullet.mail.ukl.yahoo.com with NNFMP; 03 Mar 2011 20:55:00 -0000 Received: from [127.0.0.1] by omp1018.mail.ukl.yahoo.com with NNFMP; 03 Mar 2011 20:55:00 -0000 X-Yahoo-Newman-Id: 287820.56477.bm@omp1018.mail.ukl.yahoo.com Received: (qmail 9072 invoked from network); 3 Mar 2011 20:55:00 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=btinternet.com; h=DKIM-Signature:Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=dxrIybQnYkI8NVxF/UPtr4uRJPZoNMZMJ6FouCaaJIkA/Zn9kGrBhW/cMFO5fseB5oq0jp9rXq7PU9gKGikOePt8dr+VYiDiFdRiTb3FaVP37viLP2Kd188BWEh6/F2DNbPDH4DG/ld/zL9MGux5u6gi4JM1YfEi3OeKWei5Ua0= ; DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=s1024; t=1299185700; bh=YjGskDxX8BtO2XgE1rvjj8oEwaKeT3BHhD6L8IrPL+c=; h=Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=cSVWRCVnIYj9ggV8ir80YSv5ggWRfXEPciU2otdV4Rifz4f+DoCgNr/OoGNr/Zd/OUypP32uF9tH9MAcJycPIhXLclU5U2afQcwKAwqvqcK/GeQ3xoF2o/iiAmAt1V/mMFQ+Pxpq3K7nr80toM4x8zWUQ7WtTjTSZKqdP/JhmNw= Received: from IBM7FFA209F07C (c.ashby435@81.153.43.75 with login) by smtp822.mail.ukl.yahoo.com with SMTP; 03 Mar 2011 20:54:59 +0000 GMT X-Yahoo-SMTP: .u8e2g.swBByWKjbpA3lR6Fw.2ZEQrJJpVsTSrpXLCffsPaCEMY- X-YMail-OSG: bA0Lm5wVM1nAwaMqVmJArEpv5PLiCp58ewIihSzIh3jqTHB ejClFI02D8d0mN1E8cxNeYGaInATyn2EOJ5W0QxOv8WVPZfkP8Cu4fGJLOh1 Bh1RxR.Ue0rSn92E92UDTnk4_ng4zWjGkemgSba3Rj_Pc._J0kAoCy2EQnIo qwxJW5_X9dSKv4iy.QNNN5gkW56kzNrIWwlqomjHKG6r7HpjY4hjTSWdubo_ 5aFLjIG6OVAbihmewF.6ekzKBWy70LNtkcgOLdanV7tvjww4N2B1GytD38ME fe3E7rjj9dNiC4uDM X-Yahoo-Newman-Property: ymail-3 Message-ID: <851E08B3D5AD4CC1BE6959CA1293720D@IBM7FFA209F07C> From: "Chris" To: References: <6C9E0C3D501744C99E11539B7AFCB120@IBM7FFA209F07C> Date: Thu, 3 Mar 2011 20:54:58 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5994 DomainKey-Status: good (testing) X-Spam-Score: 3.4 (+++) X-Spam-Report: autolearn=disabled,FORGED_MUA_OUTLOOK=3.36,HTML_MESSAGE=0.001,UNPARSEABLE_RELAY=0.001 Subject: Re: LF: Topband Test Content-Type: multipart/alternative; boundary="----=_NextPart_000_0086_01CBD9E5.418737F0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: *** X-Spam-Status: No, hits=3.3 required=5.0 tests=FORGED_MUA_OUTLOOK, FROM_ENDS_IN_NUMS,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-d015.1 ; domain : btinternet.com DKIM : pass x-aol-sid: 3039ac1d600a4d7000526032 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none ------=_NextPart_000_0086_01CBD9E5.418737F0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks again Andy and Markus, Yes, my feeling is that the reflective wave shift is due to doppler as= the layer changes height. We need to try it again over a longer perio= d. It is true there are a lot of aircraft between us, but would the re= sult have been so smooth? Has this effect been seen on 137kHz? The info I have seen on near vert= ical incidence/reflection suggest it should. Any thoughts on this appreciated, thanks for taking the time to commen= t. Chris, G4AYT. ----- Original Message -----=20 From: Andy Talbot=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, March 03, 2011 8:40 PM Subject: Re: LF: Topband Test No, it definitely is due to ionospheric shift. 30m/s is no big dea= l over the period of the day/night transition. 30 minutes at that spe= ed 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 =20 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 pp= m 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 airl= iners 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 indicat= ive of an object passing by at constant linear velocity. Best 73, Markus (DF6NM) From: Chris=20 Sent: Thursday, March 03, 2011 7:55 PM To: RSGB LF Group=20 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 tw= o. Nothing new or 'earth shattering' I expect, but new to us and worth= y 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 audib= le signals, maybe others have. Vy 73, Chris, G4AYT, Whitstable, UK. ------=_NextPart_000_0086_01CBD9E5.418737F0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Thanks again Andy and Markus,<= /DIV>
Yes, my feeling is that the reflectiv= e=20 wave shift is due to doppler as the layer changes height. We need= to try it=20 again over a longer period. It is true there are a lot of aircraft bet= ween us,=20 but would the result have been so smooth?
Has this effect been seen on 137kHz?= The info I=20 have seen on near vertical incidence/reflection suggest it should.
Any thoughts on this appreciated, tha= nks for taking=20 the time to comment.
Chris, G4AYT.
----- Original Message -----
From:=20 Andy=20 Talbot
Sent: Thursday, March 03, 201= 1 8:40=20 PM
Subject: Re: LF: Topband Test=

No, it definitely is due to ionospheric shift. &= nbsp;=20 30m/s is no big deal over the period of the day/night=20 transition.  30 minutes at that speed would be a mean change in= =20 height of 54km.   Not  unrealistic for an E= layer=20 (??) height of 120km
 
Try to find a copy of G3PLX's article
 
'JNT


 
On 3 March 2011 20:19, Markus Vester <markusv= ester@aol.com>=20 wrote:
Hi Chris, thanks for sharing this= unusual=20 observation.
 
From your screenshot, the split= was up to about=20 0.35 Hz, or 0.2 ppm of 1.8 MHz. Interpreted as Doppler, = a=20 reflector would have to move at least 30m/s radially from your=20 baseline. This seems a bit fast for an=20 ionospheric day-to-night shift.
 
Another possible explanation coul= d be airplane=20 scatter. Large airliners are known to have a large radar= cross=20 section at HF. Seeing that on 160 m may seem extreme,=20 but considering the wingspan of an A-380 (80 m), ha= lf-wave=20 resonant scattering is a very real possibility. The downward= =20 slope of the Doppler shifted frequency would also be=20 indicative of an object passing by at constant linear=20 velocity.
 
Best 73,
Markus (DF6NM)

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

------=_NextPart_000_0086_01CBD9E5.418737F0--