Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mp03.r1000.mx.aol.com (Internet Inbound) with ESMTP id 709EE38000125; Tue, 8 Jan 2013 15:29:53 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Tsfmy-0001Ry-Ga for rs_out_1@blacksheep.org; Tue, 08 Jan 2013 20:28:48 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Tsfmy-0001Rp-0G for rsgb_lf_group@blacksheep.org; Tue, 08 Jan 2013 20:28:48 +0000 Received: from imr-mb02.mx.aol.com ([64.12.207.163]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1Tsfmw-0002tc-08 for rsgb_lf_group@blacksheep.org; Tue, 08 Jan 2013 20:28:46 +0000 Received: from mtaout-da06.r1000.mx.aol.com (mtaout-da06.r1000.mx.aol.com [172.29.51.134]) by imr-mb02.mx.aol.com (Outbound Mail Relay) with ESMTP id 4BE5A380012FB for ; Tue, 8 Jan 2013 15:27:05 -0500 (EST) Received: from Black (188-194-147-142-dynip.superkabel.de [188.194.147.142]) by mtaout-da06.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id A3B9DE000091 for ; Tue, 8 Jan 2013 15:27:04 -0500 (EST) Message-ID: From: "Markus Vester" To: References: <428AD1894D5E4BA78368C439F5CB7A12@GaryAsus> In-Reply-To: <428AD1894D5E4BA78368C439F5CB7A12@GaryAsus> Date: Tue, 8 Jan 2013 21:27:00 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6000.16480 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16669 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1357676825; bh=1N1LyG2XqQNKmfEL/VeLt0ACIl250Hd0qhw2nZ5VaME=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=Vob2E/ERd7vW1YJ1QMRE6mZRv9XhgJqt4maIkXMaz3mqEXVRA5xHeb7Un39Vnt9QO JOJtWYzKoH3zFO2OHciNl6AlLyIoGigRlrYayQCBG3rxojyS+RDrXbNiCeKlyKHokX 0nDxH4LzggFqcPyWPBtCGdjoLqbZI24nsv5aT3Kw= X-AOL-SCOLL-SCORE: 0:2:418101408:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Gary, reminds me of those pretty little asterisk- or spider-shaped artifacts which occasionally appeared on MF and were discussed on this list a couple of years ago. I think the most plausible explanation we found was the acceleration of a brushless synchronous motor. The chopper fundamental frequency might be generated by a digital PWM controller having a stable crystal clock, and the variable sidebands are due to the rotor angle rate dependent modulation. [...] 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 [64.12.207.163 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 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: 40cd937fc1c5e6338b07d288cd09d087 Subject: LF: Re: Strange signal Content-Type: multipart/alternative; boundary="----=_NextPart_000_0015_01CDEDE6.E4D29780" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_40_50,HTML_MESSAGE, MISSING_OUTLOOK_NAME 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: mtain-mp03.r1000.mx.aol.com ; domain : mx.aol.com DKIM : fail X-AOL-OVERRIDE-PIK-REASON: Y x-aol-sid: 3039ac1dc14750ec81c110bf X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ------=_NextPart_000_0015_01CDEDE6.E4D29780 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Gary, reminds me of those pretty little asterisk- or spider-shaped artifacts = which occasionally appeared on MF and were discussed on this list a = couple of years ago. I think the most plausible explanation we found was = the acceleration of a brushless synchronous motor. The chopper = fundamental frequency might be generated by a digital PWM controller = having a stable crystal clock, and the variable sidebands are due to the = rotor angle rate dependent modulation.=20 Perhaps this one is similar? Maybe a modern laundry machine or = dishwasher coming up to speed, overshooting a while, and then settling = on the preset rpm rate.=20 Best 73, Markus (DF6NM) ----- Original Message -----=20 From: Gary - G4WGT=20 To: LF Group=20 Cc: rsgb_lf_group@yahoogroups.co.uk=20 Sent: Tuesday, January 08, 2013 8:26 PM Subject: LF: Strange signal Hi All, I am seeing a strange signal centered on 474.750 kHz. It is periodically = visible & audible on my grabber system & my JRC NRD-345. there appears = to be no data, just continuous tones. Both systems using separate = antennas. I have placed a capture on Dropbox of the grabber image & you can see = the end of a previous period & the start of a new one. The signal = pattern starts with a bulge at the beginning but just shuts off at the = end. https://dl.dropbox.com/u/15990181/472-479-1301081910.jpg I have also placed a capture from the JRC Rx with SpecLab running at = QRS01. https://dl.dropbox.com/u/15990181/capt1301081909.jpg Any ideas or knowledge of this signal ? 73, Gary - G4WGT. ------=_NextPart_000_0015_01CDEDE6.E4D29780 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Gary,
 
reminds me of those pretty little = asterisk- or=20 spider-shaped artifacts which occasionally appeared on MF and = were=20 discussed on this list a couple of years ago. I think the most plausible = explanation we found was the acceleration of a brushless = synchronous motor.=20 The chopper fundamental frequency might be generated by a digital PWM=20 controller having a stable crystal clock, and the variable = sidebands=20 are due to the rotor angle rate dependent modulation. =
 
Perhaps this one is similar? Maybe = a modern=20 laundry machine or dishwasher coming up to speed, overshooting a = while, and=20 then settling on the preset rpm rate. 
 
Best 73,
Markus (DF6NM)
 
 
----- Original Message -----=20
From: Gary - = G4WGT=20
Sent: Tuesday, January 08, 2013 8:26 PM
Subject: LF: Strange signal

Hi All,
 
I am seeing a strange signal = centered on=20 474.750 kHz. It is periodically visible & audible on my grabber = system=20 & my JRC NRD-345. there appears to be no data, just continuous = tones. Both=20 systems using separate antennas.
 
I have placed a capture on Dropbox of = the grabber=20 image & you can see the end of a previous period & the start of = a new=20 one. The signal pattern starts with a bulge at the beginning but just = shuts off=20 at the end.
 
https:/= /dl.dropbox.com/u/15990181/472-479-1301081910.jpg
 
I have also placed a capture from the = JRC Rx with=20 SpecLab running at QRS01.
 
https://dl.= dropbox.com/u/15990181/capt1301081909.jpg
 
Any ideas or knowledge of this signal=20 ?
 
73,
 
Gary - G4WGT.
 
 
------=_NextPart_000_0015_01CDEDE6.E4D29780--