Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w2VAU4b1008070 for ; Sat, 31 Mar 2018 12:30:05 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1f2DfS-0005Eq-Uq for rs_out_1@blacksheep.org; Sat, 31 Mar 2018 11:23:26 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1f2DfO-0005Eh-RH for rsgb_lf_group@blacksheep.org; Sat, 31 Mar 2018 11:23:22 +0100 Received: from omr-m007e.mx.aol.com ([204.29.186.9]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.89) (envelope-from ) id 1f2DfJ-0006M6-4M for rsgb_lf_group@blacksheep.org; Sat, 31 Mar 2018 11:23:21 +0100 Received: from mtaomg-aah02.mx.aol.com (mtaomg-aah02.mx.aol.com [172.27.1.144]) by omr-m007e.mx.aol.com (Outbound Mail Relay) with ESMTP id 0CF1E3800052 for ; Sat, 31 Mar 2018 06:23:14 -0400 (EDT) Received: from core-acd05f.mail.aol.com (core-acd05.mail.aol.com [172.27.22.15]) by mtaomg-aah02.mx.aol.com (OMAG/Core Interface) with ESMTP id BCC5438000084 for ; Sat, 31 Mar 2018 06:23:12 -0400 (EDT) Received: from 188.194.222.230 by webjasstg-vab46.srv.aolmail.net (10.96.25.113) with HTTP (WebMailUI); Sat, 31 Mar 2018 06:23:11 -0400 Date: Sat, 31 Mar 2018 06:23:12 -0400 From: Markus Vester To: rsgb_lf_group@blacksheep.org Message-Id: <1627b951913-1799-13a@webjasstg-vab46.srv.aolmail.net> In-Reply-To: MIME-Version: 1.0 X-MB-Message-Source: WebUI X-MB-Message-Type: User X-Mailer: JAS STD X-Originating-IP: [188.194.222.230] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20150623; t=1522491794; bh=aj3vUdu8/Lae1I6IIcNJ6pghniX1I79IhTokaJPcw7Y=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=xzJTzMxKKAGBHcSY+5grHXjHNJ7Wnkj2FX1oVxsGZ5vC7bjVQDrhZVrWtj1KkQZ3i PSi5odCWrVXM0mi0B+Fcts0t1UTXAJhS88X7gPUHFyQ4l5wPYr1gTEcRqQCfo23rCU fb/z1uZ2hEmIWZrDqLSQ+j6LPYVbYde3MtwvpC3U= x-aol-sid: 3039ac1b01905abf619055c2 X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Yes it is "just there", the unbalanced pulsegroups are part of the phase coding specification: http://jproc.ca/hyperbolic/loran_c_sigchar.html ++--+-+- + master A +--+++++ - master B +++++--+ secondary A +-+-++-- secondary B [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 004f7f7656eeac34aa35b19f1e48f84d Subject: Re: LF: More Phase plots Content-Type: multipart/alternative; boundary="----=_Part_347_534561042.1522491791635" 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_40_50,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 ------=_Part_347_534561042.1522491791635 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Yes it is "just there", the unbalanced pulsegroups are part of the phase co= ding specification: http://jproc.ca/hyperbolic/loran_c_sigchar.html ++--+-+- + master A +--+++++ - master B +++++--+ secondary A +-+-++-- secondary B 73, Markus -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Andy Talbot An: LineOne Verschickt: Sa, 31. Mrz 2018 12:08 Betreff: Re: LF: More Phase plots It was Peter who told me about the offset, and I wondered if I could also s= ee it - rekindling my interest in coherent LF reception (and many hours of= VB programming to update the receiver display software) ! I just looked at the central 100kHz spectral line. If you filter the signa= l narrow enough it appears very clearly Are you implying it is a function of the imbalance, because I've always ass= umed its just "there" The attached spectral plot is with a lower decimation applied, so showing s= everal Hz either side. The 7.5Hz (or whatever) spikes due to the PRI are th= ere. Andy On 31 March 2018 at 10:52, Markus Vester wrote: Hi Andy, LF, the frequency offset on the Loran signal has been present since Friday (Mar= 24). It showed up as a rainbow pattern on my monitor http://df6nm.bplaced.net/LoranView/LoranGrabber.htm and was immediately confirmed by Peter G3PLX, who then communicated the pro= blem to the ooperators. It looks like the frequency offset is alternating b= etween exactly +1ppb and -1ppb, as if a digital timing control unit were go= ing rail-to-rail while attempting to to lock to the proper time. Peter had discovered a similar phase-drift fault already in August 2016. Th= is was later fixed, but has left a permanent timing error on the master pul= segroup (on LoranView the trace is slightly left of it's.slot) Andy did you actually undo the Loran pulse phasecodes for your measurement,= or simply look at the 100.000 kHz spectral line which results from the unb= alance of the phasecode scheme (ratio of 11 to 7 positive to negative pulse= s for master, 10 to 6 for secondary) ?=20 Best 73, Markus (DF6NM) -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Andy Talbot An: LineOne ; rsgb_lf_group Verschickt: Sa, 31. Mrz 2018 9:40 Betreff: LF: More Phase plots While I'm still on a roll with high stability off-air monitoring, here is a= plot of the one remaining 100kHz transmission, from Anthorn, taken overni= ght. =20 http://www.g4jnt.com/DropF/clipboard_201803310831.png It has been reported by a few amateurs that this is exhibiting a 1 PPB freq= uency error, and that is clearly visible on my plot. The rest of the wobbl= es are multipath. Although a pulsed signal, when filtered to a narrow-eno= ugh bandwidth a stable spectral line at [exactly] 100kHz appears. There is some quite spectacular fading Andy G4JNT ------=_Part_347_534561042.1522491791635 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Yes it is "just there", the unbalanced = pulsegroups are part of the phase coding specification:
http://jpro= c.ca/hyperbolic/loran_c_sigchar.html

++--+-+- + master A
+--+++++ - master B
+= ++++--+   secondary A
+-+-++= --   secondary B

73, Markus

-----Urspr=C3=BCngliche Mitteilung-----
Vo= n: Andy Talbot <andy.g4jnt@gmail.com>
An: LineOne <= rsgb_lf_group@blacksheep.org>
Verschickt: Sa, 31. Mrz 201= 8 12:08
Betreff: Re: LF: More Phase plots
It was Peter who told me about the offset, and I wondered if = I could also see it - rekindling my interest in coherent LF reception = (and many hours of VB programming to update the receiver display software)= !

I just looked at the central= 100kHz spectral line.  If you filter the signal narrow enough it appe= ars very clearly
Are you implying it is a function of the i= mbalance, because I've always assumed its just "there"

The attached spectral plot is with= a lower decimation applied, so showing several Hz either side. The 7.5Hz (= or whatever) spikes due to the PRI are there.

Andy

=
 

On 31 = March 2018 at 10:52, Markus Vester <markusvester@aol.com> wrote:
=
Hi Andy, LF,

the = frequency offset on the Loran signal has been present since Frida= y (Mar 24). It showed up as a rainbow pattern on my monitor
= http://df6nm.bplaced.net/LoranView/LoranGrabber.htm
and was immedia= tely confirmed by Peter G3PLX, who then communicated the problem to the oop= erators. It looks like the frequency offset is alternating between exactly = +1ppb and -1ppb, as if a digital timing control unit were going rail-t= o-rail while attempting to to lock to the proper time.

Peter had discovered a similar phase-drift fault alrea= dy in August 2016. This was later fixed, but has left a permanent timing er= ror on the master pulsegroup (on LoranView the trace is slightly left of it= 's.slot)

Andy did you actually undo the Lora= n pulse phasecodes for your measurement, or simply look= at the 100.000 kHz spectral line which results from the unbalanc= e of the phasecode scheme (ratio of 11 to 7 positive to negative pulses for= master, 10 to 6 for secondary) ? 

Best 73,
Markus (DF6NM)

----= -Urspr=C3=BCngliche Mitteilung-----
Von: Andy Talbot <andy.g4jnt@gmail.com>
An: LineOn= e <rsgb_lf_group@blacksheep.org>; rsgb_lf_group <rsgb_l= f_group@yahoogroups.co.uk>
Verschick= t: Sa, 31. Mrz 2018 9:40
Betreff: LF: More Phase plots


While I'm still on a roll with h= igh stability off-air monitoring, here is a plot of the one remaining 100kH= z  transmission, from Anthorn, taken overnight.  

http://= www.g4jnt.com/DropF/clipboard_201803310831.png

It has been reported by a few amateu= rs that this is exhibiting a 1 PPB frequency error, and that is clearly vis= ible on my plot.  The rest of the wobbles are multipath.   A= lthough a pulsed signal, when filtered to a narrow-enough bandwidth a stabl= e spectral line at [exactly] 100kHz appears.

T= here is some quite spectacular fading

Andy&nbs= p; G4JNT




 

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