Return-Path: Received: from mtain-mi06.r1000.mx.aol.com (mtain-mi06.r1000.mail.aol.com [172.21.131.164]) by air-de02.mail.aol.com (v127_r1.1) with ESMTP id MAILINDE024-5ea94baf94fd34c; Sun, 28 Mar 2010 13:42:21 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mi06.r1000.mx.aol.com (Internet Inbound) with ESMTP id C01B4380000BE; Sun, 28 Mar 2010 13:42:19 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NvwTs-0003kW-7x for rs_out_1@blacksheep.org; Sun, 28 Mar 2010 18:41:00 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NvwTr-0003kN-II for rsgb_lf_group@blacksheep.org; Sun, 28 Mar 2010 18:40:59 +0100 Received: from mail-bw0-f215.google.com ([209.85.218.215]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NvwTo-0000bW-Hy for rsgb_lf_group@blacksheep.org; Sun, 28 Mar 2010 18:40:59 +0100 Received: by bwz7 with SMTP id 7so5694907bwz.4 for ; Sun, 28 Mar 2010 10:40:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:received:message-id:subject:from:to:content-type; bh=tRvsFS1+2wxZkLp20bXd5p/At7yPsVHkoDGKqC89QVo=; b=tnloRs5fZ7kdMyM5K4UVGWvMX2m04BjyOmNMjYcYVSz9S30AdgVEpeYBfRb3IZvnpf znJt0pr0UyastIUP4faHJkRqwkwfrnW3O9pNWiBbshNHW2c7M1pyCJGbP1wHi0ZcAlAG RJRYuFXfjfCufwCGC9+6rrDFuSMHj78UyOtcU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=qDmLB5u1ig8gHxmQwXVh6L5ENbtFnBHVUpzBg3NkxKOR1CY1zZ0jRYY1pGtwLfh5Ap cvUBPzbiucqzjAyUDxaIw5MWwz4Ij/bp823AwuYQq9G4oB+rUWeNK+M6JTYlBIPjoUU9 dp8XcxXCpO9yU0pBuE+rGP92YARrielHPVJQ8= MIME-Version: 1.0 Received: by 10.204.50.205 with HTTP; Sun, 28 Mar 2010 10:40:49 -0700 (PDT) In-Reply-To: <20100324105125.4F2CC31E703@smtps01.kuleuven.be> References: <20100324105125.4F2CC31E703@smtps01.kuleuven.be> Date: Sun, 28 Mar 2010 18:40:49 +0100 Received: by 10.204.8.205 with SMTP id i13mr5516298bki.109.1269798049428; Sun, 28 Mar 2010 10:40:49 -0700 (PDT) Message-ID: <9afca2641003281040g1748a9c3lc4a20004327085ae@mail.gmail.com> From: Roger Lapthorn 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: Re: LF: Re: DK7FC's 3rd VLF transmission Content-Type: multipart/alternative; boundary=001517588b98ac34f30482dfe5e1 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=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-d266.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039400cdece4baf94fb47f0 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --001517588b98ac34f30482dfe5e1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable *Jim,* Thanks for the updated preamp schematic. What would you recommend as a suitable alternative to the ZTX690B device in your 8.97kHz preamp as I don= 't think these are available nowadays? *All,* Thanks for the latest data on the VLF experiments. I'd been away for a wee= k, so missed the thread until yesterday. Sounds like Stefan's signal was received all over the place. Quite remarkable work by all concerned. 73s Roger G3XBM On 24 March 2010 11:51, Rik Strobbe wrote: > Hello Wolf, > > I will have a look at the SDR-IQ. > > About the frequency drift problem: > at QRL we frequently use lock-in technique to "receive" very weak signal= s . > Receive is between brackets as "transmitting" and "receiving" all happen= on > a 1 by 3 meter table and the frequency is between 180THz and 1.1PHz. TX > (pulsed laser) and RX (with photomultiplier serving as "active antenna")= use > a common reference frequency what cancels out any drift problem. > For VLF a signal like DCF77 is available as reference: 77.5 kHz divided= by > 26 and then multiplied by 3 gives 8942.3 Hz (what will ensure that none= of > the TX harmonics will block the reception of DCF77). > I would expect that during daytime and in a range of 500 to 1000 km arou= nd > Frankfurt the DCF77 signal will be phase stable and thus suited as a > reference for a PSK link on VLF. > > 73, > > Rik ON7YD > > > At 11:16 24/03/2010, you wrote: > >> Hi Rik, >> >> I prefer the SDR-IQ for VLF - it's less expensive than the Perseus, and >> more important, it goes down in frequency to "almost zero" (unlike Pers= eus, >> as mentioned here before). Don't get this wrong, Perseus is a superb ra= dio >> too, but there's no easy way to bypass the input bandpass (highpass).= I use >> Perseus on HF, and SDR-IQ on LF, VLF, and to listen for bats(!) . >> >> Most soundcard's are fine too, and for the next experiment, you will be >> able to use the ALPHA signals to permanently calibrate the soundcard's >> frequency drift (when extremely high FFT resolution is required). >> >> Cheers, >> Wolf DL4YHF . >> >> ----- original Nachricht -------- >> >> Betreff: Re: LF: Re: DK7FC's 3rd VLF transmission >> Gesendet: Mi 24 M=E4r 2010 09:50:19 CET >> Von: "Rik Strobbe" >> >> > Hello Roelof, >> > >> > thanks for the circuit diagram. It looks pretty simple. >> > If I "read" the circuit diagram correct it is a buffer amplifier (the >> > voltage gain maybe even less than 1, however due to the impedance >> > transformation the power gain is huge). >> > It seems a bit of overshoot to me to buy a perseus (just checked, >> > they ask 850 Euro for it), so my first option would be to go to the >> > PC soundcard. >> > Do you (or others) have any experience with that ? >> > >> > 73, Rik ON7YD >> > >> > >> > At 19:29 23/03/2010, you wrote: >> > >Hello Rick, >> > > >> > >Michael Oexner has had good results with a mini-whip E-field probe= I >> build >> > >for him. >> > >The circuit diagram is in the attachment. >> > >The feedline is CAT5 network cable. >> > > >> > >Note that the RF-isolating transformers in the signal path are not >> > correct. >> > >I have used MCL TT 1-6 parts, rated for 0.004 - 300 MHz at the -3 dB >> > >points. >> > >The common mode chokes are not optimum, as I used the parts I had on >> hand. >> > >Type 75 or 77 ferrite should be better. >> > > >> > >Michael used a PERSEUS SDR, which has a noise figure of about 25 dB= at >> 9 >> > >kHz. >> > >This is due to the fact that there is also a RF-isolating transforme= r >> in >> > >the signal path. >> > > >> > >It is amazing that with this not optimized set up it was possible to >> have >> > >good reception over a 72 km path. >> > >The actual capture area of the antenna is 30 x 40 mm single sided >> copper >> > >clad PCB. >> > > >> > >There are quite a few people around with a PERSEUS SDR, who are >> probably >> > >interested in receiving Stefan's signal. >> > >So a simple antenna design might help. >> > > >> > >I have the parts for an optical link active E-field antenna, as >> suggested >> > >by Stefan. >> > >Due to other more pressing matters, I have not yet put them to good >> use. >> > > >> > >I hope this helps, >> > > >> > >Best regards, >> > >Roelof, pa0rdt >> > > >> > > >> > > >> > > >> > >> > >> > >> >> --- original Nachricht Ende ---- >> Gratis: Jeden Monat 3 SMS versenden- Mit freenetMail - Ihrer kostenlose >> E-Mail-Adresse >> http://email.freenet.de/dienste/emailoffice/produktuebersicht/basic/sms= /index.html?pid=3D6830 >> > > > --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 --001517588b98ac34f30482dfe5e1 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Jim,
Thanks for the updated preamp schematic. What would you rec= ommend as a suitable alternative to the ZTX690B device in your 8.97kHz pre= amp as I don't think these are available nowadays?

All,<= br> Thanks for the latest data on the VLF experiments. I'd been away for= a week, so missed the thread until yesterday. Sounds like Stefan's si= gnal was received all over the place. Quite remarkable work by all concern= ed.

73s
Roger G3XBM



On 24 Mar= ch 2010 11:51, Rik Strobbe <rik.strobbe@fys.kuleuven.be> wrote:
Hello Wolf,

I will have a look at the SDR-IQ.

About the frequency drift problem:
at QRL we frequently use lock-in technique to "receive" very wea= k signals .
Receive is between brackets as "transmitting" and "receivin= g" all happen on a 1 by 3 meter table and the frequency is between 18= 0THz and 1.1PHz. TX (pulsed laser) and RX (with photomultiplier serving as= "active antenna") use a common reference frequency what cancels= out any drift problem.
For VLF a signal like DCF77 is available as reference: 77.5 kHz divided by= 26 and then multiplied by 3 gives 8942.3 Hz (what will ensure that none= of the TX harmonics will block the reception of DCF77).
I would expect that during daytime and in a range of 500 to 1000 km around= Frankfurt the DCF77 signal will be phase stable and thus suited as a refe= rence for a PSK link on VLF.

73,

Rik =A0ON7YD


At 11:16 24/03/2010, you wrote:
Hi Rik,

I prefer the SDR-IQ for VLF - it's less expensive than the Perseus, an= d more important, it goes down in frequency to "almost zero" (un= like Perseus, as mentioned here before). Don't get this wrong, Perseus= is a superb radio too, but there's no easy way to bypass the input ba= ndpass (highpass). I use Perseus on HF, and SDR-IQ on LF, VLF, and to list= en for bats(!) .

Most soundcard's are fine too, and for the next experiment, you will= be able to use the ALPHA signals to permanently calibrate the soundcard&#= 39;s frequency drift (when extremely high FFT resolution is required).

Cheers,
=A0Wolf DL4YHF .

----- original Nachricht --------

Betreff: Re: LF: Re: DK7FC's 3rd VLF transmission
Gesendet: Mi 24 M=E4r 2010 09:50:19 CET
Von: "Rik Strobbe"<rik.strobbe@fys.kuleuven.be>

> Hello Roelof,
>
> thanks for the circuit diagram. It looks pretty simple.
> If I "read" the circuit diagram correct it is a buffer ampl= ifier (the
> voltage gain maybe even less than 1, however due to the impedance
> transformation the power gain is huge).
> It seems a bit of overshoot to me to buy a perseus (just checked,
> they ask 850 Euro for it), so my first option would be to go to the > PC soundcard.
> Do you (or others) have any experience with that ?
>
> 73, Rik ON7YD
>
>
> At 19:29 23/03/2010, you wrote:
> >Hello Rick,
> >
> >Michael Oexner has had good results with a mini-whip E-field prob= e I build
> >for him.
> >The circuit diagram is in the attachment.
> >The feedline is CAT5 network cable.
> >
> >Note that the RF-isolating transformers in the signal path are no= t
> correct.
> >I have used MCL TT 1-6 parts, rated for 0.004 - 300 MHz at the -3= dB
> >points.
> >The common mode chokes are not optimum, as I used the parts I had= on hand.
> >Type 75 or 77 ferrite should be better.
> >
> >Michael used a PERSEUS SDR, which has a noise figure of about 25= dB at 9
> >kHz.
> >This is due to the fact that there is also a RF-isolating transfo= rmer in
> >the signal path.
> >
> >It is amazing that with this not optimized set up it was possible= to have
> >good reception over a 72 km path.
> >The actual capture area of the antenna is 30 x 40 mm single sided= copper
> >clad PCB.
> >
> >There are quite a few people around with a PERSEUS SDR, who are= probably
> >interested in receiving Stefan's signal.
> >So a simple antenna design might help.
> >
> >I have the parts for an optical link active E-field antenna, as= suggested
> >by Stefan.
> >Due to other more pressing matters, I have not yet put them to go= od use.
> >
> >I hope this helps,
> >
> >Best regards,
> >Roelof, pa0rdt
> >
> >
> >
> >
>
>
>

--- original Nachricht Ende ----
Gratis: Jeden Monat 3 SMS versenden- Mit freenetMail - Ihrer kostenlose E-= Mail-Adresse http://emai= l.freenet.de/dienste/emailoffice/produktuebersicht/basic/sms/index.html?pi= d=3D6830





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http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088
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