Return-Path: X-Spam-DCC: paranoid 1356; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00,HTML_50_60, HTML_MESSAGE autolearn=unavailable version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id sBC8qqfp009087 for ; Fri, 12 Dec 2014 09:52:52 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1XzLsd-0000uq-KS for rs_out_1@blacksheep.org; Fri, 12 Dec 2014 08:47:19 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1XzLsd-0000uh-BF for rsgb_lf_group@blacksheep.org; Fri, 12 Dec 2014 08:47:19 +0000 Received: from omr-m1.mx.aol.com ([64.12.224.134]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.84) (envelope-from ) id 1XzLsa-0007NM-Ns for rsgb_lf_group@blacksheep.org; Fri, 12 Dec 2014 08:47:18 +0000 Received: from mtaout-aaj01.mx.aol.com (mtaout-aaj01.mx.aol.com [172.27.3.205]) by omr-m1.mx.aol.com (Outbound Mail Relay) with ESMTP id 83EBA38000067 for ; Fri, 12 Dec 2014 03:47:14 -0500 (EST) Received: from White (ipb21bee4a.dynamic.kabel-deutschland.de [178.27.238.74]) by mtaout-aaj01.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 69C2C38000084 for ; Fri, 12 Dec 2014 03:47:13 -0500 (EST) Message-ID: <30AD70E5C47D43BC9AD184852A7F9472@White> From: "Markus Vester" To: References: <5489EFBC.3050401@abelian.org> <5489F474.4030904@abelian.org> <5489FA44.3010709@abelian.org> <548AA644.4030707@abelian.org> Date: Fri, 12 Dec 2014 09:47:12 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 12.0.1606 X-MimeOLE: Produced By Microsoft MimeOLE V12.0.1606 x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20140625; t=1418374034; bh=Ol1bvE+HRrtBRgfN8Tj7tOYn4Nsq43W6Urpb/nBGWks=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=GowKObTV1roPx4YjIdniDBkWbvbC+y9Y52AP4+sJq/Zgynff54+7a9b5kXy1Y26vb URn9fozD+zmynS4T08z7wkF8fKw5Vi7vt3enMIgx/cD2lfReGi04BtV97M1Mp65brJ eX0FebqyIWCLC+LHywIJ7oS9MsgEH9AiQgQOCFCs= x-aol-sid: 3039ac1b03cd548aab91280d X-AOL-IP: 178.27.238.74 X-Scan-Signature: e4d79cc1e5beb0f7c63f6aa3ce129e10 Subject: Re: VLF: 8819.9 Hz in Virginia? Content-Type: multipart/alternative; boundary="----=_NextPart_000_0023_01D015F0.9A6B1DF0" 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 1464 Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_0023_01D015F0.9A6B1DF0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hmm 8820 Hz is a 60 Hz multiple, so maybe not the best choice for = American observers. On the other hand, the trace at Forest seems to be = too stable for a direct mains harmonic.=20 What I often see here both at VLF and LF are crystal controlled = carriers, accompannied by sidelines at 16.7 or 50 Hz multiples, = presumably from railway power converters which are driven by a = microcontroller. Best 73, Markus From: Paul Nicholson=20 Sent: Friday, December 12, 2014 9:24 AM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: VLF: 8819.9 Hz in Virginia? Spectrogram covering 24 hours yesterday http://abelian.org/vlf/tmp/141211c.gif A wandering signal from a crystal source of average stability. These are fairly common when you dig deep enough into the noise. Fortunately easy to distinguish from a GPS locked amateur signal. Demonstrates how useless an undisciplined xtal osc is for VLF (tx and rx). -- Paul Nicholson -- ------=_NextPart_000_0023_01D015F0.9A6B1DF0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hmm 8820 Hz is a 60 Hz multiple, so = maybe=20 not the best choice for American observers. On the other hand, = the=20 trace at Forest seems to be too stable for a direct mains = harmonic.=20
 
What I often see here both at VLF and = LF are=20 crystal controlled carriers, accompannied by sidelines at 16.7 or = 50 Hz=20 multiples, presumably from railway power converters which are = driven by a=20 microcontroller.
 
Best 73,
Markus

From: Paul Nicholson
Sent: Friday, December 12, 2014 9:24 AM
To: rsgb_lf_group@blacksheep.org= =20
Subject: Re: VLF: 8819.9 Hz in Virginia?

Spectrogram covering 24 hours yesterday

  http://abelian.org/vlf/tm= p/141211c.gif

A=20 wandering signal from a crystal source of average stability.
These = are fairly=20 common when you dig deep enough into the noise.
Fortunately easy to=20 distinguish from a GPS locked amateur signal.

Demonstrates how = useless an=20 undisciplined xtal osc is for VLF
(tx and rx).

--
Paul=20 Nicholson
--

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