Return-Path: Received: from mtain-ma01.r1000.mx.aol.com (mtain-ma01.r1000.mx.aol.com [172.29.96.9]) by air-de06.mail.aol.com (v129.4) with ESMTP id MAILINDE061-5eb64c0a4f761cc; Sat, 05 Jun 2010 09:21:58 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-ma01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 84397380000AC; Sat, 5 Jun 2010 09:21:56 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OKtJ0-0001c3-74 for rs_out_1@blacksheep.org; Sat, 05 Jun 2010 14:20:54 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OKtIz-0001bu-L5 for rsgb_lf_group@blacksheep.org; Sat, 05 Jun 2010 14:20:53 +0100 Received: from mail-wy0-f171.google.com ([74.125.82.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OKtIx-0004tn-CE for rsgb_lf_group@blacksheep.org; Sat, 05 Jun 2010 14:20:53 +0100 Received: by wyb40 with SMTP id 40so1663928wyb.16 for ; Sat, 05 Jun 2010 06:20:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:sender:received :in-reply-to:references:date:x-google-sender-auth:message-id:subject :from:to:content-type; bh=yTkv1Uju0xWyOZo5GbLs/zejJUgFl+KxISRO89Tbc8s=; b=cjySjkjT8VdGs3DTSYbPPL4C/z9sUiMnQxst5dg419oGX9NQbgVTxGf3mh0Liy1Jyv JnNbI6muMKPQMCV7xjsIhWrgGFiFM939ofYnIVrhvLMfK2rwl6YLjglXxNKfOwLo/Ga1 xksOc/v5ny2ulzDjB/5P1cQYlve1A5YcfQTL4= DomainKey-Signature: a=rsa-sha1; c=nofws; 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; b=AdPg+2YNmEqLqFF1EIqQc7jqaMZCr5dzzNhZOkOJzpEEWft0zuyDZ4pA9g+FUDTlp1 BC5N2+A7M3o74H9LNON4p1vEyTu5zDFPiSnrDidPXDKWlx1MtOHp6ubzq5pcR99xnEV4 KjgS5FTTifEgE2ahkz+FvoX75nTuH/D7SkrQE= MIME-Version: 1.0 Received: by 10.216.88.196 with SMTP id a46mr721056wef.36.1275744045100; Sat, 05 Jun 2010 06:20:45 -0700 (PDT) Received: by 10.216.169.17 with HTTP; Sat, 5 Jun 2010 06:20:45 -0700 (PDT) In-Reply-To: <657E7065AC4C454AB63F6C7C2FF043F6@Black> References: <657E7065AC4C454AB63F6C7C2FF043F6@Black> Date: Sat, 5 Jun 2010 14:20:45 +0100 X-Google-Sender-Auth: vwbyD6HmNoF178neT0jmQkgmeS0 Message-ID: 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: VLF: Two-Way QSO on Dreamer's Band Content-Type: multipart/alternative; boundary=0016e68fa338a1fe460488484ee5 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-d241.1 ; domain : gmail.com DKIM : fail x-aol-sid: 3039ac1d60094c0a4f7403f4 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --0016e68fa338a1fe460488484ee5 Content-Type: text/plain; charset=ISO-8859-1 Marcus, Walter, LF, Well done for your VLF 8.97 Hz 2 - way communication. Keep up the good work. Monitoring most of the time here but nothing seen as yet, one day I may see something. 73 Gary - G4WGT - North West England - IO83QO On 4 June 2010 21:59, Markus Vester wrote: > Dear LF, > > this morning, June 4th between 6 and 8 UT, Walter (DJ2LF) and myself > (DF6NM) were able to successfully conduct a two-way contact (aka "QSO") on > 8.97 kHz. The distance between us is 20.2 km, well outside the reactive near > field zone (lamda / 2pi = 5.3 km). > > Both of us were using our small backyard Marconi antennas at home, for > transmit and receive. Walter's antenna has 260 pF at an estimated effective > height of about 5 m. He achieved about 370 mA current, resulting in a > radiated power of about 5 uW (EMRP). I also got 5 uW from 270 mA into 240 pF > at about 7 m. I resonated the antenna using the same little "yoghurt coil" > described a while ago, having 1.3 henry from 9 x 480 turns of 0.2 mm magnet > wire, and a room-temperature DC resistance of 820 ohms. Walter used a scaled > up version of this coil, about 25 cm diameter and 60 cm long, consisting of > seven polypropylene household buckets inserted into one another. Each bucket > has 460 turns of 0.4 mm wire on it, about 320 ohms total DC resistance. Each > of us applied approximately 100 W of "RF" power from a car-HiFi amplifier. > > Reception was done by soundcard, without preamplification. We set Spectrum > Lab to 0.95 mHz FFT bandwidth, with noise blanking on, and samplerate > tracking based on the German 23.4 kHz MSK signal. We chose to transmit 30 > minute dashes, separated by 15 minute quiet intervals to allow for FFT > processing delay. > > We employed a special "micro-QSO" format, which was designed to exchange > the minimum single-bit report and confirmation in only three turnovers, each > containing a single dash. Station identification was by frequency alone, > with preassigned pairs (8969.92 / 8970.02 Hz for DJ2LF, 8970.0 / 8970.1 Hz > for DF6NM). Generally the lower frequency was assigned to a negative > response (ie. "not confirmed"), whereas the upper one is positive ("received > ok"). > > DF6NM started by transmitting a carrier on his lower frequency, from 4:00 > to 4:30 UT. This was indeed seen by DJ2LF, who replied on his upper > frequency from 4:45 to 5:15, reporting positive reception. Then DF6NM > confirmed reception on the upper frequency from 5:30 to 6:00. The whole > procedure took two hours. > > Attached are screenshots from both sides. Unfortunately the QRN level this > morning was much worse than we had hoped for, with active thunderstorms in > South Italy, Poland and Belorussia. To my surprise, our dashes still made it > through and were unambiguously visible, with an estimated SNR of 6 to 8 dB. > Walter's signal can actually still be seen between my own dashes on my VLF > grabber http://www.mydarc.de/df6nm/vlf/vlfgrabber.htm . > > As far as we know, this was probably the first two-way amateur QSO on VLF, > using truely radiated fields. Another dream came true... > > Best regards, > Markus (DF6NM) > --0016e68fa338a1fe460488484ee5 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Marcus, Walter, LF,

Well done for your VLF 8.97 Hz 2 -= way communication.

Keep up the good work.
<= div>
Monitoring most of the time here but nothing seen as ye= t, one day I may see something.

73

Gary - G4WGT -=A0North Wes= t England - IO83QO



On 4 June 2010 21:59, Markus Vester <= ;markusvester@aol.com> wrote:
Dear LF,
=A0
this morning, June 4th between 6 and= 8 UT, Walter=20 (DJ2LF) and myself (DF6NM) were able to successfully conduct a two-way con= tact=20 (aka "QSO") on 8.97 kHz. The distance between us is 20.2 km, wel= l outside the=20 reactive near field zone (lamda / 2pi =3D 5.3 km).
=A0
Both of us were using our small backy= ard Marconi=20 antennas at home, for transmit and receive. Walter's antenna has 260= pF at an=20 estimated effective height of about 5 m. He achieved about 370 mA current,= =20 resulting in a radiated power of about 5 uW (EMRP). I also got 5 uW from= 270 mA=20 into 240 pF at about 7 m. I resonated the antenna using the same little &q= uot;yoghurt=20 coil" described a while ago, having 1.3 henry from 9 x 480 turns of= 0.2 mm=20 magnet wire, and a room-temperature DC resistance of 820 ohms. Walter used= a=20 scaled up version of this coil, about 25 cm diameter and 60 cm long, consi= sting=20 of seven polypropylene household buckets inserted into one another. Each= bucket=20 has 460 turns of 0.4 mm wire on it, about 320 ohms total DC resistance. Ea= ch of=20 us applied approximately 100 W of "RF" power from a car-HiFi=20 amplifier.
=A0
Reception was done by soundcard, with= out=20 preamplification. We set Spectrum Lab to 0.95 mHz FFT bandwidth, with nois= e=20 blanking on, and samplerate tracking based on the German 23.4 kHz MSK sign= al. We=20 chose to transmit 30 minute dashes, separated by 15 minute quiet intervals= to=20 allow for FFT processing delay.
=A0
We employed a special "micro-QSO= " format, which was=20 designed to exchange the minimum single-bit report and confirmation in onl= y=20 three turnovers, each containing a single dash. Station identification was= by=20 frequency alone, with preassigned pairs (8969.92 / 8970.02 Hz for DJ2LF,= 8970.0=20 / 8970.1 Hz for DF6NM). Generally the lower frequency was assigned to a ne= gative=20 response (ie. "not confirmed"), whereas the upper one is positiv= e ("received=20 ok").
=A0
DF6NM started by transmitting a carri= er on his=20 lower frequency, from 4:00 to 4:30 UT. This was indeed seen by DJ2LF, who= =20 replied on his upper frequency from 4:45 to 5:15, reporting positive recep= tion.=20 Then DF6NM confirmed reception on the upper frequency from 5:30 to 6:00.= The=20 whole procedure took two hours.
=A0
Attached are screenshots from both si= des.=20 Unfortunately the QRN level this morning was much worse than we had hoped= for,=20 with active thunderstorms in South Italy, Poland and Belorussia. To my=20 surprise,=A0our dashes still made it through and were=A0unambiguously=20 visible, with an estimated SNR of 6 to 8 dB. Walter's=A0signal can act= ually=20 still be seen between my own dashes on=A0my VLF grabber http://www.mydar= c.de/df6nm/vlf/vlfgrabber.htm=20 .
=A0
As far as we know, this was probably= the first=20 two-way amateur QSO on VLF, using truely radiated fields. Another dream ca= me=20 true...
=A0
Best regards,
Markus=20 (DF6NM)

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