Return-Path: Received: from mtain-mb01.r1000.mx.aol.com (mtain-mb01.r1000.mx.aol.com [172.29.96.21]) by air-db09.mail.aol.com (v129.4) with ESMTP id MAILINDB091-85f54c1949552; Wed, 16 Jun 2010 17:59:49 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mb01.r1000.mx.aol.com (Internet Inbound) with ESMTP id BBFAD380001DF; Wed, 16 Jun 2010 17:59:47 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OP0dQ-00020E-32 for rs_out_1@blacksheep.org; Wed, 16 Jun 2010 22:59:00 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OP0dO-0001zV-F4 for rsgb_lf_group@blacksheep.org; Wed, 16 Jun 2010 22:58:58 +0100 Received: from mail-fx0-f43.google.com ([209.85.161.43]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OP0dH-0001fL-35 for rsgb_lf_group@blacksheep.org; Wed, 16 Jun 2010 22:58:58 +0100 Received: by fxm12 with SMTP id 12so2321325fxm.16 for ; Wed, 16 Jun 2010 14:58:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=0OoJNnd7E2nu9u/jgivTdz0/KUgtWiiK0IzGLeA0yrM=; b=Nw979puQ6eq9xx7rPqMqwhNIjdsL+g0OKlBlvte4O4CUdAANG7t0CS/35gVV/eIMzC Z3YZ6+6K2qjXQk0L43yqMs22iZuDVrP5Z90GpuIHnN1K73QCoqD0WVopKq5m0HpUFWi+ l9K6GwT7LblXwG+kYZlgvZGDhSzALz4o9zqjc= 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 :content-type; b=wfmJ0dWkmvaMjZMcOSoiKAq+v0c4v3qRfMUAMqpIT/ptpLXpdyEEnFLuljVKxA86Qw ZJ4T8oelWz5lk+1Vw/itrohjr9FjSsPzcG8WHzcnTnDhzhjp+WNO0WK5YGDF6EE3fo+B IQKo89nPfk5jNe0ZgJpaWf5zjiMm9/Ps/YM70= MIME-Version: 1.0 Received: by 10.204.3.65 with SMTP id 1mr7011545bkm.210.1276725524681; Wed, 16 Jun 2010 14:58:44 -0700 (PDT) Received: by 10.204.52.141 with HTTP; Wed, 16 Jun 2010 14:58:44 -0700 (PDT) In-Reply-To: References: Date: Wed, 16 Jun 2010 22:58:44 +0100 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: 1.9kHz earth-mode tests today Content-Type: multipart/alternative; boundary=0015174c0c705fd41b04892cd3da 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_20_30, HTML_FONTCOLOR_UNSAFE,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 x-aol-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m233.2 ; domain : googlemail.com DKIM : pass x-aol-sid: 3039ac1d60154c1949531262 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --0015174c0c705fd41b04892cd3da Content-Type: text/plain; charset=ISO-8859-1 Make a crystal calibrator. See RadCom December 2009 Page 50 Andy www.g4jnt.com On 16 June 2010 22:03, Roger Lapthorn wrote: > Today I modified my 4W VLF transmitter so it could send either a 10 wpm or > QRSS3 beacon signal. I also went out into the fields with my loop/preamp and > a PC with Spectran to receive it. > For the first attempt with a PC I went 0.3km away from home where the 4W > signal from the earth electrode "antenna" could clearly be received by ear. > With Spectran I could read the 10wpm CW signal with 20dB S/N in a 12Hz > bandwidth, if my understanding of the Spectran settings is right. There is > an audio recording hereso you can judge the S/N yourselves. This suggests that with QRSS3 (or > slower still) and really screwing the bandwidth down I should be able to do > much better. My problem is knowing how to calibrate the soundcard etc and > clearly I need a more stable source than my free running twin-tee audio > oscillator. I am a total novice when it comes to using QRSS and soundcards > using very narrow bandwidths. > > 73s > Roger G3XBM > > -- > http://g3xbm-qrp.blogspot.com/ > http://www.g3xbm.co.uk > http://www.youtube.com/user/g3xbm > G3XBM GQRP 1678 ISWL G11088 > --0015174c0c705fd41b04892cd3da Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Make a crystal calibrator.=A0
See RadCom=A0 December 2009=A0=A0 Page 50
On 16 June 2010 22:03, Roger Lapthorn <rogerlapthorn@gmai= l.com> wrote:
Today I modified my 4W VLF tra= nsmitter so it could send either a 10 wpm or QRSS3 beacon signal. I also= went out into the fields with my loop/preamp and a PC with Spectran to receiv= e it. For the first attempt with a PC I went 0.3km away from home where th= e 4W signal from the earth electrode "antenna" could clearly be= received by ear. With Spectran I could read the 10wpm CW signal with 20dB= S/N in a 12Hz bandwidth, if my understanding of the Spectran settings is= right. There is an audio rec= ording here so you can judge the S/N yourselves. This suggests that wi= th QRSS3 (or slower still) and really screwing the bandwidth down I should= be able to do much better. My problem is knowing how to calibrate the sou= ndcard etc and clearly I need a more stable source than my free running tw= in-tee audio oscillator. I am a total novice when it comes to using QRSS= and soundcards using very narrow bandwidths.

73s
Roger G3XBM

--
http://g3xbm-qrp.blogspot.= com/
http://w= ww.g3xbm.co.uk
http://www= .youtube.com/user/g3xbm
G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G110= 88

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