Return-Path: Received: from mtain-dj03.r1000.mx.aol.com (mtain-dj03.r1000.mail.aol.com [172.19.187.139]) by air-mb06.mail.aol.com (v128.1) with ESMTP id MAILINMB061-a6fc4bbc82f81f7; Wed, 07 Apr 2010 09:04:56 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-dj03.r1000.mx.aol.com (Internet Inbound) with ESMTP id 183F2380000E2; Wed, 7 Apr 2010 09:04:54 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NzUvE-0004mv-K2 for rs_out_1@blacksheep.org; Wed, 07 Apr 2010 14:03:56 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NzUvE-0004mm-15 for rsgb_lf_group@blacksheep.org; Wed, 07 Apr 2010 14:03:56 +0100 Received: from mail-bw0-f219.google.com ([209.85.218.219]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NzUvA-0003EM-Ak for rsgb_lf_group@blacksheep.org; Wed, 07 Apr 2010 14:03:56 +0100 Received: by bwz19 with SMTP id 19so44757bwz.4 for ; Wed, 07 Apr 2010 06:03:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:received:message-id:subject:from:to:cc:content-type; bh=+dIx+h/3dM26+MMEstp1Scpo2hKQCOu1JTrr5F30sII=; b=cqN/Uz/haOF9iXYX6xn+i/Yt7Onreu9oIEdFKoJA3yuzrN7O6mIrTJOwCotX49yYsZ Dey3tZnGGK/AoupLJm3yFuvCqutrSE2ouV/TcO6dDPJDV+fD0c2MCMWQHG1vKRwwbdt+ o4WruQKJ/o0RzJLafjtermWgwmNX+62asnMQU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=t6Pg1chR8sW9NzU8+bxkDerVWa6vw+cQdYWd+RDHKucyQfBaiLaGRPoNit5Gn35InJ CF/PFeezdXdXVPMDS4VUZpbAjlXZlDyxAskKg3Visfx9ksEvJxJy10WsLDGIIHYe4W1o o87z+DSgAwItW6jtBWWbKTt52PD7tsklRUsTM= MIME-Version: 1.0 Received: by 10.204.120.212 with HTTP; Wed, 7 Apr 2010 06:03:43 -0700 (PDT) In-Reply-To: <4BBC5D04.1030404@abelian.org> References: <4BBAC662.4050205@freenet.de> <4BBACC66.9080308@abelian.org> <4BBBBC63.6070005@abelian.org> <4BBC3CC6.3080506@iup.uni-heidelberg.de> <4BBC5D04.1030404@abelian.org> Date: Wed, 7 Apr 2010 14:03:43 +0100 Received: by 10.204.152.140 with SMTP id g12mr9790149bkw.130.1270645423893; Wed, 07 Apr 2010 06:03:43 -0700 (PDT) Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org Cc: Linda Holtby DomainKey-Status: good (testing) X-Spam-Score: 0.3 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,MAILTO_TO_SPAM_ADDR=0.276 Subject: Re: VLF: Auroral Chorus Content-Type: multipart/alternative; boundary=0015175cfec8206cee0483a5310f X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.6 required=5.0 tests=HTML_20_30, HTML_FONTCOLOR_UNSAFE,HTML_MESSAGE,MAILTO_TO_SPAM_ADDR 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: mail_rly_antispam_dkim-m258.1 ; domain : googlemail.com DKIM : pass x-aol-sid: 3039cdbc9d074bbc82f60642 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --0015175cfec8206cee0483a5310f Content-Type: text/plain; charset=ISO-8859-1 While we're on natural radio phenonema... These were recorded years ago in 1997, in the early days of amateur radio DSP. They are of a carrier on 3572kHz transmitted, from me to G3PLX in Cumbria, The off-air signal was mixed down and decimated then recorded at a sampling rate of 7.2 Hz in baseband I/Q format in a bandwidth of about 3Hz using the old 56002 DSP system of that era, Then they were speeded up 1000 times by the simple expedinnt of calling the sampling rate 7200Hz, then mixed up to give an audio tone and converted to .WAV files. It was exactly the same hardware used at Peter's end as for our record-setting first ever QRSS signal on 73kHz a few months before these were made. The audio drift is the doppler due to the ionosphere moving over the several hours of monitoring. http://www.g4jnt.com/DownLoad/3572Z.WAV http://www.g4jnt.com/DownLoad/3572H.WAV http://www.g4jnt.com/DownLoad/3572H1.WAV Andy www.g4jnt.com On 7 April 2010 11:23, Paul Nicholson wrote: > > > For me almost unbelivable that it is a recorded electromagnetic > > wave? > > No wonder it is called 'natural' radio. > > But not half as strange as Saturn's aurora recorded by Cassini, > > http://www.nasa.gov/wav/123163main_cas-skr1-112203.wav > > This emission was 50-60kHz, 27 minutes squashed into > 73 seconds and shifted down to audio range. > -- > Paul Nicholson > -- > > > --0015175cfec8206cee0483a5310f Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
While we're on natural radio phenonema...
These were recorded years ago in 1997, in the early days of amateur= radio=A0DSP.=A0 They are of a carrier on 3572kHz transmitted, from me to= G3PLX in Cumbria,=A0
=A0
The off-air signal=A0was mixed down and decimated then recorded=A0at= a sampling rate of 7.2 Hz in baseband I/Q format in a bandwidth of=A0 abo= ut 3Hz using the old=A056002 DSP system of that era, =A0 Then they were sp= eeded up 1000 times by the simple expedinnt of calling the sampling rate= 7200Hz, then mixed=A0up to give an audio tone and converted to .WAV files= .=A0=A0 It was exactly the same hardware used at Peter's end as=A0for= our record-setting first ever QRSS signal on 73kHz a few months before th= ese were made.
=A0
The audio drift is the doppler due to the ionosphere moving over the= several hours of monitoring.
=A0
=A0
=A0
On 7 April 2010 11:23, Paul Nicholson <vlf0308@abelian.org> wrote:

> For me almost unbelivable that it is a recorded= electromagnetic
> wave?

No wonder it is called 'na= tural' radio.

But not half as strange as Saturn's aurora re= corded by Cassini,

=A0http://www.nasa.gov/wav/123163main_cas-skr1-112203.wav<= /a>

This emission was 50-60kHz, 27 minutes squashed into
73 seco= nds and shifted down to audio range.
--
Paul Nicholson
--



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