Return-Path: Received: from mtain-mc07.r1000.mx.aol.com (mtain-mc07.r1000.mx.aol.com [172.29.96.79]) by air-dc08.mail.aol.com (v127_r1.1) with ESMTP id MAILINDC083-86544baf98cc39f; Sun, 28 Mar 2010 13:58:36 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mc07.r1000.mx.aol.com (Internet Inbound) with ESMTP id 9A26838000094; Sun, 28 Mar 2010 13:58:34 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NvwjO-0003uz-NA for rs_out_1@blacksheep.org; Sun, 28 Mar 2010 18:57:02 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NvwjO-0003uq-1d for rsgb_lf_group@blacksheep.org; Sun, 28 Mar 2010 18:57:02 +0100 Received: from mail-wy0-f171.google.com ([74.125.82.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NvwjL-0000hU-KN for rsgb_lf_group@blacksheep.org; Sun, 28 Mar 2010 18:57:02 +0100 Received: by wyb32 with SMTP id 32so4337523wyb.16 for ; Sun, 28 Mar 2010 10:56:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:received:message-id:subject :from:to:content-type; bh=ldcWUGkPs0SM/UImQVoQLmrGYQ+Ur4lL3K1Nq+Ox1Lg=; b=nbSEuwNGfTibUYxB7A/HLA6k3efhGootS6Va529E639lVBDqBFgmJnIMnpnZCBIV5c xe1aSKRrushfufL34B/8GdnZEtTMX3nTK0LndJnKpFZa85ocWm5XA34C6M9DSZKC/iv8 9U5qRC/IBA7ONP70G6fLDxA9il5WbxX+7CJCg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=AxeJU/qzBIMgnfI76uuCPFhamvMYTBRPt0hIOWfz1TowmW3k4zgUA5BI2EM/gNC1tU gdWfiNcrWceQX+0OBS/QM3EVuR4HlO1wsO7LBS+K2iT2OhSmiak2SA7Kzc5ZYkJ6g5m9 iZRViYg9ufn5LOjdNe9+JDQOAsMwaiW9BEy40= MIME-Version: 1.0 Received: by 10.216.163.144 with HTTP; Sun, 28 Mar 2010 10:56:51 -0700 (PDT) In-Reply-To: <9afca2641003281040g1748a9c3lc4a20004327085ae@mail.gmail.com> References: <20100324105125.4F2CC31E703@smtps01.kuleuven.be> <9afca2641003281040g1748a9c3lc4a20004327085ae@mail.gmail.com> Date: Sun, 28 Mar 2010 18:56:51 +0100 X-Google-Sender-Auth: 1b1b250fe8d4716f Received: by 10.216.88.212 with SMTP id a62mr2393337wef.72.1269799011634; Sun, 28 Mar 2010 10:56:51 -0700 (PDT) Message-ID: <1f0624b91003281056k515c9b2dhd51f1c74093d206@mail.gmail.com> From: Gary - G4WGT 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=0016e6d64559064ed40482e01f2d X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=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-m206.2 ; domain : googlemail.com DKIM : fail x-aol-sid: 3039ac1d604f4baf98ca4878 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --0016e6d64559064ed40482e01f2d Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Roger, You can obtain the ZTX690B from Mode Components in Birmingham, I just got= 5 off. http://www.modecomponents.co.uk/ Chris Tredwell G8CHW. Cheers, Gary - G4WGT. On 28 March 2010 18:40, Roger Lapthorn wrote: > *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 > week, 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 signa= ls >> . >> Receive is between brackets as "transmitting" and "receiving" all happe= n >> 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 aro= und >> 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, an= d >>> more important, it goes down in frequency to "almost zero" (unlike Per= seus, >>> 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 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 (th= e >>> > 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 transform= er >>> 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 kostenlos= e >>> E-Mail-Adresse >>> http://email.freenet.de/dienste/emailoffice/produktuebersicht/basic/sm= s/index.html?pid=3D6830 >>> >> >> >> > > > -- > http://g3xbm-qrp.blogspot.com/ > http://www.g3xbm.co.uk > http://www.youtube.com/user/g3xbm > G3XBM GQRP 1678 ISWL G11088 > --0016e6d64559064ed40482e01f2d Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Roger,

You can obtain the ZTX690B from Mode Componen= ts in Birmingham, I just got 5 off.

=

Chris Tred= well G8CHW.

Cheers,

Gary= - G4WGT.


On 28 March 2010 18= :40, Roger Lapthorn <rogerlapthorn@gmail.com> wrote:
Jim,
Thanks for the updated pre= amp 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 avai= lable nowadays?

All,
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 March 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





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

--0016e6d64559064ed40482e01f2d--