Return-Path: Received: from mtain-dg05.r1000.mx.aol.com (mtain-dg05.r1000.mx.aol.com [172.29.65.13]) by air-dc04.mail.aol.com (v129.4) with ESMTP id MAILINDC043-86504d7146d43c6; Fri, 04 Mar 2011 15:08:52 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dg05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 40E14380000E7; Fri, 4 Mar 2011 15:08:50 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PvbIH-0000cs-CM for rs_out_1@blacksheep.org; Fri, 04 Mar 2011 20:08:09 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PvbIG-0000cg-MK for rsgb_lf_group@blacksheep.org; Fri, 04 Mar 2011 20:08:08 +0000 Received: from mail-iy0-f171.google.com ([209.85.210.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PvbID-0002C7-Ds for rsgb_lf_group@blacksheep.org; Fri, 04 Mar 2011 20:08:08 +0000 Received: by iyf40 with SMTP id 40so3086223iyf.16 for ; Fri, 04 Mar 2011 12:07:59 -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=+QnWpieuLqr13PJotzEp45guuoBNYqHol4koCb6e/f0=; b=oWIHNvyYETEKgErTUaYm15rC7RDaVp8Wh5eaiUZmQ6x2aIvH47Uj3r8M9Fhgheya9t rnuzhk1qkPLvA8yOgYqv5j80/4fFVN3M5EqoVIYosQOjlOL2n5AWhk1IFwiONEeelwmj QJ/3YX/9tKUydHpr8sVxMi2oEDH5P+yBXJCas= 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=i4aowxV31XI/2HFVoI2nmSS/3iW4SVMaRdegTh91ZXrQ65toUoFeX3b7/X9U8FdLbT xxyd2VxOCA/2tDQuYp6HgVsGwpmOpYYht+YD6oyBHBCHx6Qsi4mUTbzXVNNRZtTOnViY 52VLhCbGUY4VXnBmdi8L+oa2Kz0X9w/TS4udo= MIME-Version: 1.0 Received: by 10.231.185.106 with SMTP id cn42mr767883ibb.53.1299269265216; Fri, 04 Mar 2011 12:07:45 -0800 (PST) Received: by 10.231.199.197 with HTTP; Fri, 4 Mar 2011 12:07:45 -0800 (PST) In-Reply-To: References: Date: Fri, 4 Mar 2011 20:07:45 +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: Re: Topband ionogram trace Content-Type: multipart/alternative; boundary=001636d344ca0556f6049dadb3af 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-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d009.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d410d4d7146d27601 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) --001636d344ca0556f6049dadb3af Content-Type: text/plain; charset=ISO-8859-1 I could put up a topband carrier as well. By placing it a few Hz away from yours, can try for a double plot ? Andy www.g4jnt.com On 4 March 2011 19:58, Chris wrote: > Thanks Andy, great stuff. I think we can be pretty sure it was as you > suggested and not aircraft. > If it was aircraft it would be there all the time presumably. > Pete and I plan to repeat the test when we can, probably next week, will > let you know if we see the same thing again. > Vy 73, > Chris, G4AYT. > > ----- Original Message ----- > *From:* Andy Talbot > *To:* rsgb_lf_group@blacksheep.org > *Sent:* Friday, March 04, 2011 7:18 PM > *Subject:* LF: Topband ionogram trace > > Here's Peter's update on the 'unusual' topband split trace. Might explain > its cleanliness > > Andy > www.g4jnt.com > > ---------- Forwarded message ---------- > From: Peter Martinez > Date: 4 March 2011 18:35 > Subject: Re: Dopplergrams 12 years ago > To: Andy Talbot > > > Andy: > > I had a look at the QRSS sample that G4AYT captured. Around the same time I > was watching the signal from the Fairford ionosonde. This sweeps from > 1625kHz, through top-band and on up to 13MHz. At that time it was clear that > the Fcrit was getting down towards 2MHz so the F-layer was rising rapidly so > this would have been responsible for the increasing negative Doppler shift > he was seeing on one of the traces. In fact the MUF on the Fairford-Kendal > path dropped below 1.7MHz at about 3 am that night. There was also evidence > of night-time sporadic-E. This is sometimes known as Auroral sporadic E but > it isn't 'auroral' in the sense we usually mean, but refers to patches of Es > which drift south from the Auroral oval, probably initiated by the same > particle precipitation that causes aurora. This Es activity could have been > responsible for the non-Doppler-shifted trace that G4AYT saw. On a normal > night only the F-layer would be reflecting on top-band. > > Fairford now has a new ionosonde equipment, a Digisonde DPS-4D which I find > is much easier to 'eavesdrop' on. The Digisondes are pulse sounders with the > receiver co-located with the transmitter with the receiver synchronised to > the transmitter locally. They didn't need to be locked to anything and they > weren't stable. The new one behaves rather better, stepping exactly 25kHz > exactly every 640mS (locked to GPS). I have my system stepping in sync and > have some crude ionograms already and have confirmed that the pulse timing > is accurate and stable. The next job is to implement the pulse-compression > algorithm, which is very similar to that used by LORAN C. This will give me > real-time ionograms again, a facility I lost when the UK chirpsounders > closed down last year. > > > 73 > Peter > > ----- Original Message ----- From: "Andy Talbot" > To: > Sent: Thursday, March 03, 2011 7:59 PM > Subject: Dopplergrams 12 years ago > > > Hi Peter - >> Cast your mind back. We did some of the first Dopplergram tests on >> 1967kHz >> back in 1998, and produced the plots shown >> >> http://www.g4jnt.com/Download/1967jnt1.jpg >> http://www.g4jnt.com/Download/1967jnt3.jpg >> http://www.g4jnt.com/Download/1967jnt4.jpg >> >> Can you recall the vertical span on the trace? As far as I recall, your >> EVM software decimated from 8kHz, then you set 80% of the samplinbg rate >> as plot BW, so 3.125, 6.25Hz etc But t'would be interesting to know for >> sure. >> >> Someone on the LF reflector (see below) has just posted the plot of some >> QRSS topband tests, and was "surprised" to see the trace splitting. So I >> looked out these to show what was done over a decade ago. >> >> Andy >> >> >> >> On 3 March 2011 18:55, Chris wrote: >> >> 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. >>> >>> >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 10.0.1204 / Virus Database: 1435/3479 - Release Date: 03/03/11 >> > > > --001636d344ca0556f6049dadb3af Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
I could put up a topband carrier as well.=A0=A0 By placing it a few= Hz away from yours, can try=A0for a double plot ?
=A0
Andy


=A0
On 4 March 2011 19:58, Chris = <c.ashby435@btinternet.com= > wrote:
Thanks Andy, great stuff. I think we= can be pretty sure it was as you suggested and not aircraft.
If it was aircraft it would be there= all the time presumably.
Pete and I plan to repeat the test wh= en we can, probably next week, will let you know if we see the same thing= again.
Vy 73,
Chris, G4AYT.
----- Original Message -----
Sent: Friday, March 04, 2011 7:18= PM
Subject: LF: Topband ionogram trace=

Here's Peter's update on the 'unusual' topband split= trace.=A0=A0 Might explain its cleanliness
=A0
Andy
=A0
---------- Forwarded message ----------
From: Peter Martinez <peter.martinez@btinternet.com<= /a>>
Date: 4 March 2011 18:35
Subject: Re: Dopplergrams 12 years ago
To:= Andy Talbot <andy.g4jnt@gmail.com>


Andy:

I had a look at the= QRSS sample that G4AYT captured. Around the same time I was watching the= signal from the Fairford ionosonde. This sweeps from 1625kHz, through top= -band and on up to 13MHz. At that time it was clear that the Fcrit was get= ting down towards 2MHz so the F-layer was rising rapidly so this would hav= e been responsible for the increasing negative Doppler shift he was seeing= on one of the traces. In fact the MUF on the Fairford-Kendal path dropped= below 1.7MHz at about 3 am that night. There was also evidence of night-t= ime sporadic-E. This is sometimes known as Auroral sporadic E but it isn&#= 39;t 'auroral' in the sense we usually mean, but refers to patches= of Es which drift south from the Auroral oval, probably initiated by the= same particle precipitation that causes aurora. This Es activity could ha= ve been responsible for the non-Doppler-shifted trace that G4AYT saw. On= a normal night only the F-layer would be reflecting on top-band.

Fairford now has a new ionosonde equipment, a Digisonde DPS-4D which= I find is much easier to 'eavesdrop' on. The Digisondes are pulse= sounders with the receiver co-located with the transmitter with the recei= ver synchronised to the transmitter locally. They didn't need to be lo= cked to anything and they weren't stable. The new one behaves rather= better, stepping exactly 25kHz exactly every 640mS (locked to GPS). I hav= e my system stepping in sync and have some crude ionograms already and hav= e confirmed that the pulse timing is accurate and stable. The next job is= to implement the pulse-compression algorithm, which is very similar to th= at used by LORAN C. =A0This will give me real-time ionograms again, a faci= lity I lost when the UK chirpsounders closed down last year.


73
Peter

----- Original Message ----- From: "A= ndy Talbot" <andy.g4jnt@gmail.com>
To: <peter.martinez@btinternet.com>= ;
Sent: Thursday, March 03, 2011 7:59 PM
Subject: Dopplergrams 12 years= ago


Hi Peter -
Cast your mind back. =A0We did some of the first Dopple= rgram tests on 1967kHz
back in 1998, and produced the plots shown
http://www.g4jnt.com/Download/1967jnt1.jpg
h= ttp://www.g4jnt.com/Download/1967jnt3.jpg
http://www.g4jnt.com/Downl= oad/1967jnt4.jpg

Can you recall the vertical span on the trace? =A0 As far as I recall,= your
EVM software decimated from 8kHz, then you set 80% of the samplin= bg rate
as plot BW, so 3.125, 6.25Hz etc =A0 =A0But t'would be inte= resting to know for
sure.

Someone on the LF reflector (see below) =A0has just posted th= e plot of some
QRSS topband tests, and was "surprised" to see= the trace splitting. =A0So I
looked out these to show what was done ov= er a decade ago.

Andy



On 3 March 2011 18:55, Chris <c.ashby435@btinternet.com> wrote:

=A0Hi All,
Yesterday evenin= g Pete, M0FMT, transmitted QRSS on topband for a test. An
unexpected ef= fect was noticed with the trace splitting in two. Nothing new
or 'earth shattering' I expect, but new to us and worthy of furthe= r
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.




-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.= 0.1204 / Virus Database: 1435/3479 - Release Date: 03/03/11



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