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 w8T9p3mB001219 for ; Sat, 29 Sep 2018 11:51:05 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1g6BpV-0005U6-4m for rs_out_1@blacksheep.org; Sat, 29 Sep 2018 10:46:29 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1g6BpT-0005Tx-5h for rsgb_lf_group@blacksheep.org; Sat, 29 Sep 2018 10:46:27 +0100 Received: from omr-a015e.mx.aol.com ([204.29.186.63]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.91_59-0488984) (envelope-from ) id 1g6BpQ-00061S-9O for rsgb_lf_group@blacksheep.org; Sat, 29 Sep 2018 10:46:26 +0100 Received: from mtaomg-aah01.mx.aol.com (mtaomg-aah01.mx.aol.com [172.27.1.143]) by omr-a015e.mx.aol.com (Outbound Mail Relay) with ESMTP id 327DC3800084 for ; Sat, 29 Sep 2018 05:46:23 -0400 (EDT) Received: from core-acx10a.mail.aol.com (core-acx10.mail.aol.com [172.27.155.135]) by mtaomg-aah01.mx.aol.com (OMAG/Core Interface) with ESMTP id DD37D38000082 for ; Sat, 29 Sep 2018 05:46:22 -0400 (EDT) Received: from 188.194.221.221 by webjasstg-vaa25.srv.aolmail.net (10.96.25.28) with HTTP (WebMailUI); Sat, 29 Sep 2018 05:46:22 -0400 Date: Sat, 29 Sep 2018 05:46:22 -0400 From: Markus Vester To: rsgb_lf_group@blacksheep.org Message-Id: <16624b8cc4b-1ec2-3c2d@webjasstg-vaa25.srv.aolmail.net> In-Reply-To: <16624a5d996-1ec8-1b47@webjasstg-vab55.srv.aolmail.net> MIME-Version: 1.0 X-MB-Message-Source: WebUI X-MB-Message-Type: User X-Mailer: JAS STD X-Originating-IP: [188.194.221.221] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20150623; t=1538214383; bh=qad8V5R4/MNCSr4zgJ+BtglaKDS7C48182X83a0SrO8=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=iOiJUL/4AkjLduF8AgJ/e6rJqrOnW+RcBn8tY169N31Tf5vlai+/4+uduUjOpLGBQ 1Inq630picP36StcKzBbYQQbHfInXKLrs7CsmiWEGRfkA8amhTpPi6i6XI2GahE8pk CidBLpGLy76jd3HnN+UGzoc6EErzP0YVYwiu8tnM= x-aol-sid: 3039ac1b018f5baf49ee04ea 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 @@CONTACT_ADDRESS@@ for details. Content preview: PS: Why does the displayed bandwidth in opds vary so much? To maximise sensitivity, opds is using synchroneous AM demodulation, and an estimate for the carrier is extracted from the central peak in the spectrum. To cope with spread from propagation and TX/RX instability, the peak is evaluated down to it's -10 dB points, which is the width indicated in the output. For random phase symbols the spectrum won't contain a discrete central peak but will look like a ragged noise hump, approiximately as wide as the symbol rate. Depending on unpredictable details of the shape of the spectrum, the point where it meets the -10 dB criterion may vary arbitrarily. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [204.29.186.63 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 SPF_PASS SPF: sender matches SPF record -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: 63130203bdd9ddf2cbf93b2de3d1651e Subject: Re: LF: Signal bandwidth in Op32 LF Content-Type: multipart/alternative; boundary="----=_Part_20981_150802331.1538214382667" 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 ------=_Part_20981_150802331.1538214382667 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable PS: Why does the displayed bandwidth in opds vary so much? To maximise sensitivity, opds is using synchroneous AM demodulation, and an= estimate for the carrier is extracted from the central peak in the spectru= m. To cope with spread from propagation and TX/RX instability, the peak is = evaluated down to it's -10 dB points, which is the width indicated in the o= utput. For random phase symbols the spectrum won't contain a discrete centr= al peak but will look like a ragged noise hump, approiximately as wide as t= he symbol rate. Depending on unpredictable details of the shape of the spec= trum, the point where it meets the -10 dB criterion may vary arbitrarily. Opds sensitivity should be about 3 to 4 dB better for coherent signals. Fo= r incoherent signals, the carrier estimate uses wider bandwidth and becomes= fast enough to partially track the random symbol phases, approximating sta= ndard AM demodulation by rectification.=20 Best 73, Markus -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Markus Vester An: rsgb_lf_group Verschickt: Sa, 29. Sept 2018 11:27 Betreff: Re: LF: Signal bandwidth in Op32 LF Yes. As Andy says, if you are using a divider it should run continuously to= preserve carrier phase. All modulation (either XOR for EbNaut-PSK, or on-o= ff-gating for Opera) should be applied after the divider stage. Best 73, Markus -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Andy Talbot An: LineOne Verschickt: Sa, 29. Sept 2018 10:44 Betreff: Re: LF: Signal bandwidth in Op32 LF If you stop and start a divider, the phase jumps about randomly. Each time= you start the divider, its output signal starts up in a differnet phase to= what it would have been if left running To achieve phase coherent, you must keep the divider running and gate the O= UTPUT separately This issue is a problem with beacons in general that employ FSK keying for = their CW ident. If they adopted on-off keying, then long term integration= cold take place though the keying cycle. But unfortunately, IARU (or what= ever organisation that tries to mandate these things), appear to require FS= K keying. SO most beacon keepers comply. (I don't, the Bell Hill microwa= ve beacons, GB3SCx all use on-off keying) Andy www.g4jnt.com On Sat, 29 Sep 2018 at 09:10, VIGILANT Luis Fern=C3=A1ndez wrote: Hi LF=20 I'm puzzled with the readings of bandwidth at the Op32 correlation detectio= n grabbers As source I'm using a GPS generated signal, which is coherent in phase and = works for EbNaut So I tested this at 20x frequency to drive an small D class PA and modulate= d in Opera32 The OOK was achieved by enabling/disabling a divider by 10 just after GPS Sourprisingly, my decodes at DF6NM and DL0AO varied in width, but always sh= owing width of a non coherent signal 2018-09-24 16:55:09 EA5DOM 1500km 137485.051Hz 71mHz -99.9dBOp 78% 17.6d= B 2018-09-24 15:35:10 EA5DOM 1500km 137485.026Hz 114mHz -99.9dBOp 100% 17.3d= B=20 2018-09-24 14:13:18 EA5DOM 1500km 137485.039Hz 164mHz -37.2dBOp 100% 20.7d= B 2018-09-27 19:08:06 EA5DOM 1536km 137485.013Hz 110mHz -38.3dBOp 94% 18.8d= B Last night I tried without PA. Using just a mosfet driver this time gettin= g about 1W output. The GPS generates the 10x frequency and the OOK is control= led by enabling/disabling the divider by 10. Got a couple of decodes at DF6NM 2018-09-29 02:17:39 EA5DOM 1500km 137485.007Hz 5mHz -46.4dBOp 85% 15.4d= B 2018-09-29 00:37:50 EA5DOM 1500km 137484.986Hz 112mHz -43.2dBOp 100% 19.6d= B So, 5 and 112mHz, for the same signal. I'm thinking that the problem is cau= sed by glitches when the signal goes off. A synchronous off would be needed to cut signal at zero crossing ? Reports to other stations, like SM2DJK, show just 2 to 3mHz Any ideas ? PS: Stefan. Your Op32 correlaton detector is not working actually 73 de Luis EA5DOM ------=_Part_20981_150802331.1538214382667 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
PS: Why does the displayed bandwidth in opds vary s= o much?

To maximise sensitivity, opds is using synchroneous AM demod= ulation, and an estimate for the carrier is extracted from the central= peak in the spectrum. To cope with spread from propagation and TX/RX = instability, the peak is evaluated down to it's -10 dB points, which is the= width indicated in the output. For random phase symbols the spectrum won't= contain a discrete central peak but will look like a ragged noise hum= p, approiximately as wide as the symbol rate. Depending on unpred= ictable details of the shape of the spectrum, the point where it meets the = -10 dB criterion may vary arbitrarily.

Opds sensitivity should be ab= out 3 to 4 dB better  for coherent signals. For incoherent signals, th= e carrier estimate uses wider bandwidth and becomes fast enough to par= tially track the random symbol phases, approximating standard AM demodulati= on by rectification. 

Best 73,
Markus


-----Urspr= =C3=BCngliche Mitteilung-----
Von: Markus Vester <markusvester@aol.c= om>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschi= ckt: Sa, 29. Sept 2018 11:27
Betreff: Re: LF: Signal bandwidth in Op32 L= F

Yes. As Andy says, i= f you are using a divider it should run continuously to preserve carrier ph= ase. All modulation (either XOR for EbNaut-PSK, or on-off-gating for Opera)= should be applied after the divider stage.

Best 73,
Markus
<= br>
-----Urspr=C3=BCngliche Mitteilung-----
Von: Andy Talbot <andy.g4jnt@gmail.com>
An: Li= neOne <rsgb_lf_group@bla= cksheep.org>
Verschickt: Sa, 29. Sept 2018 10:44
Betreff: Re: = LF: Signal bandwidth in Op32 LF

If you stop and start a divider, the phase jumps about = randomly.  Each time you start the divider, its output signal starts u= p in a differnet phase to what it would have been if left running

To achieve phase coherent, you must keep the divider running and g= ate the OUTPUT separately

<= /div>
This issue is a problem with be= acons in general that employ FSK keying for their CW ident.   If = they adopted on-off keying, then long term integration cold take place thou= gh the keying cycle.  But unfortunately, IARU (or whatever organisatio= n that tries to mandate these things), appear to require FSK keying.  = SO most beacon keepers comply.   (I don't, the Bell Hill microwav= e beacons, GB3SCx all use on-off keying)
<= div>
Andy
<= span style=3D"font-size: 12.8px;">www.g4jnt.com
<= div>
<= /div>

On Sat, 29 Sep 2018 at 09:10, VIGILANT Luis Fern=C3=A1ndez <= luis@vigilant.es> wrote:
Hi LF

I'm puzzled with the readings of bandwidth at the Op32 correlation det= ection grabbers

As source I'm using a GPS generated signal, which is coherent in phase= and works for EbNaut
So I tested this at 20x frequency to drive an small D class PA and mod= ulated in Opera32
The OOK was achieved by enabling/disabling a divider by 10 just after = GPS

Sourprisingly, my decodes at DF6NM and DL0AO varied in width, but alwa= ys showing width of a non coherent signal
2018-09-24 16:55:09 EA5DOM  1500km 13=
7485.051Hz  71mHz -99.9dBOp  78% 17.6dB
2018-09-24 15:35:10 EA5DOM  1500km 137485.026Hz 114mHz -99.9dBOp 100% 17.3d=
B 
2018-09-24 14:13:18 EA5DOM  1500km 13=
7485.039Hz 164mHz -37.2dBOp 100% 20.7dB
2018-09-27 19:08:06 EA5DOM  1536km 13=
7485.013Hz 110mHz -38.3dBOp  94% 18.8dB
Last night I tried without PA.  Using=
 just a mosfet driver this time getting
about 1W output. The GPS generates th=
e 10x frequency and the OOK is controlled
by enabling/disabling the divider by =
10. Got a couple of decodes at DF6NM
2018-09-29 02:17:39 EA5DOM  1500km 13=
7485.007Hz   5mHz -46.4dBOp  85% 15.4dB
2018-09-29 00:37:50 EA5DOM  1500km 137484.986Hz 112mHz -43.2dBOp 100% 19.6d=
B
So, 5 and 112mHz, for the same signal=
. I'm thinking that the problem is caused
by glitches when the signal goes off.=
 A synchronous off would be needed to
cut signal at zero crossing ?
Reports to other stations, like SM2DJ=
K, show just 2 to 3mHz

Any ideas ?

PS: Stefan. Your Op32 correlaton dete=
ctor is not working actually

73 de Luis
EA5DOM
 
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