Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mh04.r1000.mx.aol.com (Internet Inbound) with ESMTP id E87F938000093; Sun, 25 Sep 2011 05:18:20 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1R7kq9-0005YY-H9 for rs_out_1@blacksheep.org; Sun, 25 Sep 2011 10:17:37 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1R7kq8-0005YP-To for rsgb_lf_group@blacksheep.org; Sun, 25 Sep 2011 10:17:36 +0100 Received: from mail-vx0-f171.google.com ([209.85.220.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1R7kq6-0000hO-7Z for rsgb_lf_group@blacksheep.org; Sun, 25 Sep 2011 10:17:36 +0100 Received: by vcbfk12 with SMTP id fk12so3792961vcb.16 for ; Sun, 25 Sep 2011 02:17:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; bh=YDSy8jjNHwwQLKrIEpLXa+a/RP4/zFD0R9RJT0RlQDk=; b=cM0fZcO/XqcMh1FlAkxcHunHFAEymlKk18bQQXztvGaoN6G4h9tSKTt3cdtoCglH2y 0PPFlhdJph+QMeYWhJuuNQaV+7h3aYR5h/D7iJpE2PEZgOEd5oP8nUxcm8uXPP0J5Lm5 j3BnvxXO/UY7F0cgHvW/P292Qi+S8x6toXDws= MIME-Version: 1.0 Received: by 10.52.175.135 with SMTP id ca7mr5313562vdc.171.1316942247607; Sun, 25 Sep 2011 02:17:27 -0700 (PDT) Received: by 10.220.194.195 with HTTP; Sun, 25 Sep 2011 02:17:27 -0700 (PDT) In-Reply-To: <4E7E5E90.8070404@iup.uni-heidelberg.de> References: <976E96347FDF49FEB91588B891BF47AF@White> <4E7E5E90.8070404@iup.uni-heidelberg.de> Date: Sun, 25 Sep 2011 10:17:27 +0100 X-Google-Sender-Auth: zx38p3g6xKID3qPaNWPB14DGnHs Message-ID: From: Gary - G4WGT To: rsgb_lf_group@blacksheep.org X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: DF6NM 23-09-2011 Content-Type: multipart/alternative; boundary=bcaec5101c71dbbc4a04adc0824f X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,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-SCORE: 0:2:502848128:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d233.1 ; domain : gmail.com DKIM : fail x-aol-sid: 3039ac1d60d84e7ef1dc1696 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --bcaec5101c71dbbc4a04adc0824f Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Stefan & All, Thanks for your comments & suggestions, I like the cheap GPS idea best as running more & more app's on the PC causes more & more hiccups. I presume the GPS module would be a stand alone device, any help with this method would be appreciated. Thanks & 73, Gary - G4WGT. 2011/9/24 Stefan Sch=E4fer > ** > Hello Gary, > > About sound card locking on LF: Actually its the same like on VLF except > the need for injecting a reference frequency. > If you decide to receive VLF in a separate SL instance and maybe even > separate soundcard (e.g. a 3 EUR USB soundcard from amazon) then you lock > that soundcard as usual to your VLF reference signal such as GQD and > generate e.g. 10 kHz on the output, which will be locked too then. Then y= ou > can inject this 10 kHz ref signal to the LF soundcard... > Or buy such a cheep GPS receiver instead, as often suggested here. My who= le > VLF RX, LF RX and LF TX system is based on that 10 kHz reference signal f= rom > the GPS module... > > 73, and thanks for the grabber! :-) > > Stefan/DK7FC > > Am 24.09.2011 21:12, schrieb Gary - G4WGT: > > Hi Marcus, LF, > > Pleased it provided useful feedback. > > I am hoping to optimise the system, both from the receiver stability & > SpecLab. The receiver is quite good but does show temperature stability > issues at these narrow systems. I am considering trying a similar sound c= ard > receiver to the one Stefan DK7FC has recently posted in his mails. > > I am not at all sure about sound card sampling correction at this > frequency range, I have no problem at the 8.970kHz range with using the M= SK > transmissions at VLF but with the narrow bandwidth of the system at 137kH= z > it presents a different situation for me. > > Thank you for your suggestions, I will try them in due course. > > 73, Gary - G4WGT. > > > On 24 September 2011 17:55, Markus Vester wrote: > >> Hi Gary, >> >> this is excellent, and much appreciated! I had basically tried to provid= e >> a readable signature on Chris' grabbers, but in the end QRSS 1200 turned= out >> to be a bit fast for those. I guess the general concept is more suitable= for >> straight unmodulated carriers... >> >> Your screenshot reveals my transmit instability near the end of the "N", >> when my (DHO-based) samplerate locking temporarily failed, and the >> audio frequency jumped by 20 mHz. Do you have plans for further >> optimization? The Loran line visible on 137780.419 (Anthorn et al) may c= ome >> in handy to evaluate sensitivity and stability during development. >> >> One thing I would perhaps suggest is to activate the "one pixel per FFT >> bin" option in Speclab. If you don't, and zoom in instead, the brightnes= s of >> each pixel is driven by the highest power from a number of adjacent FFT >> bins, which in effect increases the visible noise level significantly. O= f >> course the downside is that the visible range becomes quite narrow, >> requiring TX stations to cuddle closely around a prescribed QRG to be se= en >> on the grabber slot. On the other hand, you can still move the slot arou= nd a >> posteriori, and manually search for possible missed activity. >> >> Best 73, and thanks >> >> Markus (DF6NM) >> >> >> *From:* Gary - G4WGT >> *Sent:* Saturday, September 24, 2011 12:26 PM >> *To:* LF Group (RSGB) >> *Subject:* LF: DF6NM 23-09-2011 >> >> Hi Marcus, LF, >> >> Please forgive the frequency accuracy & stability on my experimental >> very slow (2 mHz) SpecLab screen but the signal is clearly visible. >> >> Receiver - JRC NRD-345 >> Antenna - PA0RDT Mini-Whip at 9 metres >> >> 73 >> >> Gary - G4WGT >> >> > --bcaec5101c71dbbc4a04adc0824f Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Stefan & All,

Thanks for your comments & sugg= estions, I like the cheap GPS idea best as running more & more app'= s on the PC causes more & more hiccups. I presume the GPS module would = be a stand alone device, any help with this method would be appreciated.

Thanks & 73,

Gary - G4WGT.=


2011/9/24 Stefan Sch=E4fer <Stefan.Schaefer@iup.uni-heidelberg.de>
=20
Hello Gary,

About sound card locking on LF: Actually its the same like on VLF except the need for injecting a reference frequency.
If you decide to receive VLF in a separate SL instance and maybe even separate soundcard (e.g. a 3 EUR USB soundcard from amazon) then you lock that soundcard as usual to your VLF reference signal such as GQD and generate e.g. 10 kHz on the output, which will be locked too then. Then you can inject this 10 kHz ref signal to the LF soundcard...
Or buy such a cheep GPS receiver instead, as often suggested here. My whole VLF RX, LF RX and LF TX system is based on that 10 kHz reference signal from the GPS module...

73, and thanks for the grabber! :-)

Stefan/DK7FC

Am 24.09.2011 21:12, schrieb Gary - G4WGT:
Hi Marcus, LF,

Pleased it provided useful feedback.

I am hoping to optimise the system, both from the receiver stability & SpecLab. The receiver is quite good but does show temperature stability issues at these narrow systems. I am considering trying a similar sound card receiver to the one Stefan DK7FC has recently posted in his mails.

I am not at all sure about sound card sampling correction at this frequency range, I have no problem at the 8.970kHz range with using the MSK transmissions at VLF but with the narrow bandwidth of the system at 137kHz it presents a different situation for me.

Thank you for your suggestions, I will try them in due course.

73, Gary - G4WGT.


On 24 September 2011 17:55, Markus Vester <markusvester@aol.com> wrote:
Hi Gary,
=A0
this is excellent, and much appreciated!=A0I had basically=A0tried to provide a readable signature on Chris' grabbers, but in the end QRSS 1200=A0turned out to be=A0a bit fa= st for those.=A0I guess the general concept=A0is=A0more suitable for straight unmodulated carriers...
=A0
Your screenshot=A0reveals my=A0transmit instability near the end of the "N", when=A0my (DHO= -based) samplerate locking temporarily=A0failed, and the audio=A0frequency jumped=A0by 20 mHz. Do you have plan= s for further optimization? The Loran line visible on 137780.419=A0(Anthorn et al) may come in handy to evaluate sensitivity and stability during=A0development.
=A0
One thing I would perhaps suggest=A0is to activate the "one pixel per FFT bin" option in Sp= eclab. If you don't, and zoom=A0in instead, the brightness of each pixel is driven by the=A0highest power from=A0a number of adjacent FFT bins, which in effect increases the visible noise level=A0significantly. Of course the downside is that the visible range becomes quite narrow, requiring=A0TX stations to=A0cuddle closely around a prescribed QRG to be seen on the grabber slot.=A0On the other hand, you can still move the slot around a posteriori, and manually search for possible missed activity.
=A0
Best 73, and thanks
=A0
Markus (DF6NM)
=A0

Sent: Saturday, September 24, 2011 12:26 PM
Subject: LF: DF6NM 23-09-2011

Hi Marcus, LF,

Please forgive the frequency accuracy & stability on my experimental very slow (2 mHz) SpecLab screen but the signal is clearly visible.

Receiver - JRC NRD-345
Antenna - PA0RDT Mini-Whip at 9 metres

73

Gary - G4WGT



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