Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,RCVD_IN_DNSWL_MED, SPF_PASS,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: : mailn 1480; Body=2 Fuz1=2 Fuz2=2 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v0GBEwDY012078 for ; Mon, 16 Jan 2017 12:14:59 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1cT5Bh-0002sN-ET for rs_out_1@blacksheep.org; Mon, 16 Jan 2017 11:10:57 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1cT5Bg-0002sB-IW for rsgb_lf_group@blacksheep.org; Mon, 16 Jan 2017 11:10:56 +0000 Received: from omr-a001e.mx.aol.com ([204.29.186.53]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.87) (envelope-from ) id 1cT5Bd-0002Gg-O1 for rsgb_lf_group@blacksheep.org; Mon, 16 Jan 2017 11:10:55 +0000 Received: from mtaomg-mbd01.mx.aol.com (mtaomg-mbd01.mx.aol.com [172.26.252.15]) by omr-a001e.mx.aol.com (Outbound Mail Relay) with ESMTP id 337A6380008B for ; Mon, 16 Jan 2017 06:10:51 -0500 (EST) Received: from core-acb09h.mail.aol.com (core-acb09.mail.aol.com [172.27.24.9]) by mtaomg-mbd01.mx.aol.com (OMAG/Core Interface) with ESMTP id C49F738000086 for ; Mon, 16 Jan 2017 06:10:50 -0500 (EST) Received: from 80.146.228.78 by webprd-a75.mail.aol.com (10.72.52.225) with HTTP (WebMailUI); Mon, 16 Jan 2017 06:10:50 -0500 Date: Mon, 16 Jan 2017 06:10:50 -0500 From: Markus Vester To: rsgb_lf_group@blacksheep.org Message-Id: <159a6f8f4d8-6153-11eba@webprd-a75.mail.aol.com> In-Reply-To: <587C8DC8.3040209@abelian.org> MIME-Version: 1.0 X-MB-Message-Source: WebUI X-MB-Message-Type: User X-Mailer: JAS STD X-Originating-IP: [80.146.228.78] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20150623; t=1484565051; bh=IPs60cg0kNyidgXboasZ6TcFAk5MWywRD/iFyhWX2ZI=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=BcpXWsgsRkgRDddWDSUn8EYGiBXRhIbjPdAdepAhpQokMUYoyOCNA10cRoFIkxPkX Mq6WuIRJtrmrFHWNklWS4C22DZ7l76ioEaKPjJEP2jyyN37daWGQggOfBLFK9akMQt Slo3Xlv+yxZ695spq8hTinqs81xuarNkJOSQTLq0= x-aol-sid: 3039ac1afc0f587caa3a70c4 X-Scan-Signature: 1bc6486c2865e7dc2ff7578e6d7fc226 Subject: Re: VLF: Carrier on 8270.0025 Hz Content-Type: multipart/alternative; boundary="----=_Part_91069_1893535216.1484565050581" 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 2.75 Status: O X-Status: X-Keywords: X-UID: 10200 ------=_Part_91069_1893535216.1484565050581 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable > Audible at 8270, not 16450. Can anyone explain why the sound is at the si= gnal frequency and not the 2nd harmonic? I "broke my head" a lot over that question. First I thought of a magnetic b= ias from earth's field but the effect turned out to be much too weak. My cu= rrent assumption is that plastic surfaces aquire a static charge due to cor= ona, and the AC voltage on the coil lets it vibrate in the DC electrostatic= field. =20 Best 73, Markus -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Paul Nicholson An: rsgb_lf_group Verschickt: Mo, 16 Jan 2017 10:12 am Betreff: Re: VLF: Carrier on 8270.0025 Hz Stefan wrote: > Since 22:45 UTC i'm running a plain and stable carrier > Carrier stopped 00:05 UTC. A strong signal! About 0.35 fT, 18.0 dB in 208uHz. Could have sent 11 chars with the 80 minute signal. vtread -T 2017-01-15_22:45,+80m /raw | # Extract signal, 3 chans vtmix -c 0.866/-20,-0.5/-35,-0.85 | # Antenna mix and phase EQ vtfilter -h bp,f=3D8270,w=3D3000 | # 3kHz bandpass vtblank -a2.2 -d0 -t1 | # Blanking vtmult -f8270.0025 | # Mix down to baseband I/Q vtresample -r240 | # Drop to 240 samples/sec vtraw -oa | # Convert to 3 column ASCII ebnaut -r240 -dp16K25A -N11 -S2.8 -PS -c8 -L350000 -v found rank 399 ber 4.0035e-01 Eb/N0 -0.6 M -2.546543181e-01 [***********] ps [ 2 30 30 30 30] > but the BEEEEP is very loud! Audible at 8270, not 16450. Can anyone explain why the sound is at the signal frequency and not the 2nd harmonic? -- Paul Nicholson -- ------=_Part_91069_1893535216.1484565050581 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
> Audible at 8270, not 16450. Can anyone explain why= the sound is at the signal frequency and not the 2nd harmonic?

I "b= roke my head" a lot over that question. First I thought of a magnetic bias = from earth's field but the effect turned out to be much too weak. = ;My current assumption is that plastic surfaces aquire a static charge= due to corona, and the AC voltage on the coil lets it vibrate in= the DC electrostatic field.  

Best 73,
Markus

-= ----Urspr=C3=BCngliche Mitteilung-----
Von: Paul Nicholson <vlf0403@= abelian.org>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>Verschickt: Mo, 16 Jan 2017 10:12 am
Betreff: Re: VLF: Carrier on 8270= .0025 Hz


Stefan wrote:

> Since 22:45 UTC i'm ru= nning a plain and stable carrier
> Carrier stopped 00:05 UTC.
A strong signal! About 0.35 fT, 18.0 dB in 208uHz.

Could have sen= t 11 chars with the 80 minute signal.

vtread -T 2017-01-15_22:45,+= 80m /raw | # Extract signal, 3 chans
vtmix -c 0.866/-20,-0.5/-35,-0= .85 | # Antenna mix and phase EQ
vtfilter -h bp,f=3D8270,w=3D3000 = | # 3kHz bandpass
vtblank -a2.2 -d0 -t1 | # Blankin= g
vtmult -f8270.0025 | # Mix down to baseband I/Q
vtre= sample -r240 | # Drop to 240 samples/sec
vtraw -oa | = # Convert to 3 column ASCII
ebnaut -r240 -dp16K25A -N11 -S2.8 -P= S -c8 -L350000 -v

found rank 399 ber 4.0035e-01 Eb/N0 -0.6
M -2.5= 46543181e-01 [***********] ps [ 2 30 30 30 30]

> but th= e BEEEEP is very loud!

Audible at 8270, not 16450. Can anyone expla= in why the sound
is at the signal frequency and not the 2nd harmonic?
--
Paul Nicholson
--

------=_Part_91069_1893535216.1484565050581--