Delivered-To: daveyxm@virginmedia.com Received: by 10.50.237.98 with SMTP id vb2csp75682igc; Sun, 2 Feb 2014 07:32:54 -0800 (PST) X-Received: by 10.180.11.233 with SMTP id t9mr8774299wib.1.1391355172327; Sun, 02 Feb 2014 07:32:52 -0800 (PST) Return-Path: Received: from post.thorcom.com (post.thorcom.com. [195.171.43.25]) by mx.google.com with ESMTP id g10si8510351wja.90.2014.02.02.07.32.51 for ; Sun, 02 Feb 2014 07:32:52 -0800 (PST) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org; dkim=pass header.i=@gmail.com; dmarc=pass (p=NONE dis=NONE) header.from=gmail.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1W9ya8-0007xl-3u for rs_out_1@blacksheep.org; Sun, 02 Feb 2014 15:03:36 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1W9ya7-0007xc-C6 for rsgb_lf_group@blacksheep.org; Sun, 02 Feb 2014 15:03:35 +0000 Received: from mail-qc0-f169.google.com ([209.85.216.169]) by relay1.thorcom.net with esmtps (TLSv1:RC4-SHA:128) (Exim 4.77) (envelope-from ) id 1W9ya4-0006IK-3N for rsgb_lf_group@blacksheep.org; Sun, 02 Feb 2014 15:03:34 +0000 Received: by mail-qc0-f169.google.com with SMTP id w7so9801298qcr.28 for ; Sun, 02 Feb 2014 07:03:30 -0800 (PST) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=Euub2vSKp3UF9RGrOphChxW01C4gDpYN1pKlDl+Rwyw=; b=WCc0nLYrJpQwgaLzMKh8GtlsWM7SLb2I4k8Z1Gd+PGFzlxOMskFCmFPjq5CQDkd0m1 srGQrI6eZr6atxNe/NGQvHsBfghbOguvg3qjelYCEvB6Tw+LwAAqQG+NBEY9G2+hfDf+ E0JI3YAHu1ZMWUurV92QdoduJ30/83gyKK+qAV6o/9QGSQI9tCQrAQU76td3ml8/DvZU F9/PQ3C7K7wDXglutBPqNkgfSUanar/2O7PQUAxmUbF85LN6ZnuuuR8txr9GwmQ4Ce6c 4TU2SL764BAXURxaNpiNtLlJPTnw0mZbbU/aY3PEWhO5UNr+DsjdDSsQW8BK8RtXe4Rq edCg== MIME-Version: 1.0 X-Received: by 10.224.124.74 with SMTP id t10mr48553288qar.40.1391353410479; Sun, 02 Feb 2014 07:03:30 -0800 (PST) Received: by 10.229.135.199 with HTTP; Sun, 2 Feb 2014 07:03:30 -0800 (PST) In-Reply-To: <52EE55E2.7020602@iup.uni-heidelberg.de> References: <000f01cf1d9e$700b49e0$0802a8c0@acer> <52EA67D4.3060604@iup.uni-heidelberg.de> <08be01cf1de6$5b817c90$128475b0$@comcast.net> <52EBB90D.6040101@iup.uni-heidelberg.de> <52ED24D7.8030405@iup.uni-heidelberg.de> <2C298FA71DBE4891AD19AFA27DEF513B@White> <52EE42B9.30006@iup.uni-heidelberg.de> <5A61157818CE4049A4ABE989EBD7AE5C@White> <52EE55E2.7020602@iup.uni-heidelberg.de> Date: Sun, 2 Feb 2014 15:03:30 +0000 Message-ID: From: Roger Lapthorn To: "rsgb_lf_group@blacksheep.org" X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: With 420uHz or 47uHz BW could be very readable with Marcus. 73s Roger G3XBM On 2 February 2014 14:27, Stefan Schäfer < wrote: [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.216.169 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (rogerlapthorn[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: d7b6e02b91d1bc9fedf732bdb432c3bc Subject: Re: LF: DX VLF experiments in 3HD Content-Type: multipart/alternative; boundary=001a11c29512c9ea2204f16db550 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, TO_ADDRESS_EQ_REAL 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 --001a11c29512c9ea2204f16db550 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable With 420uHz or 47uHz BW could be very readable with Marcus. 73s Roger G3XBM On 2 February 2014 14:27, Stefan Sch=E4fer < Stefan.Schaefer@iup.uni-heidelberg.de> wrote: > Markus, > > I am 16 dB stronger now! > > > Am 02.02.2014 14:52, schrieb Markus Vester: > > So what should be expected here? Scaling the fieldstrength from 1 km to > 180 km (1/r^3 to lambda/2/pi, 1/r thereafter), the signal should be 82 > dB weaker here on 5.755, and 63 dB weaker on 17.265 kHz. Neglecting > ionospheric contributions (not really correct), and assuming similar nois= e > levels (though 5.5 kHz is much affected by railway QRM here), my SNR in > 0.47mHz should theoretically have been > 35 - 82 + 10 dB =3D -37 dB on 5 kHz and > 50 - 63 + 10 dB =3D -3 dB on 17 kHz. > So while a detection on the fundamental seems pretty hopeless, the third > harmonic should already be getting close. > > Yes, the QRN and QRM is much lower in 3HD :-) Why didn't we get this idea > earlier??? > > > What is the inductance of the loading coil? > > Ehm , i didn't really measured it, it's just trial and error. > > > Would be interesting to see a picture of the scope trace picked up near > the antenna ;-) > > Looks quite good but could cause misunderstandings... > > The amperemeter in the coil shows 350 mA now! There is some kind of > selfoscillations, audible. Thus i do not rise the power even more. Have t= o > search, find and fix this problem later. The AC voltage from the > vari-transformer is 110V now, so there is room for at least another 6 dB. > Power is in the range of 100W now. > > I'm going to measure the strength at home now. Hopefully the signal is > audible :-) Yesterday it was still weaker than the mains hum, so far away > from any interferences! > > 73, Stefan > > > > Best 73, > Markus (DF6NM) > > > *From:* Stefan Sch=E4fer > *Sent:* Sunday, February 02, 2014 2:06 PM > *To:* rsgb_lf_group@blacksheep.org > *Subject:* Re: LF: DX VLF experiments in 3HD > > Markus, VLF, > > Am 01.02.2014 20:34, schrieb Markus Vester: > > Stefan, > > running two 478 =B5Hz "6000" windows centered on 5755 Hz (on the grabber, > but much QRM here) and also 17265 Hz (offline) which seems more quiet. So > hoping for a long carrier... > > Well, i hope that 16 hours key down were long enough ;-) > > On which of the two frequencies would you expect to radiate more power? > > I don't know. But the harmonic signal is very weak and cannot cause > interferences for JXN or HWU or SAQ or GBZ... > > I've done measurements at home, 950m distance, of that *5.755 kHz*transmi= ssion and saw that the signal was very weak, see attachment. Just 50 > dB SNR in 4.5 mHz at 3HD. The TX power was just 15W at the end. Also the > frequency response of the active antenna + soundcard is attached. > > The experiments are very interesting here and i like to do the > measurements. Despite rain the coil was on the top of the building and on > air. It was just covered by a trash bag. The voltages are very small... > I just hang out a 30cm long wire connected to a probe of the oscilloscope > and so the voltage waveform of the antenna wire. It nearly looks as > expected :-) > > Now i got another idea. There is a 2.2 uF WIMA MKP-10 capacitor in series > to the output of the H bridge, just to protect it against damage in case = of > a DC output. Now i've disconnected the antenna and tuned for the series > resonance of this C and the L of the primary winding of the loading coil. > The resonance is at 1.77 kHz. This allowed me to calculate a much smaller > additional series C which helps to attenuate unwanted frequency component= s, > i.e. makes the spectrum cleaner and provides a lower impedance on the > wanted frequency :-) > > There is really no alternative to that H bride PA which works from 10 Hz > to 100 kHz :-) > > in a few minutes i will be on air again for a longer time, hopefully with > a much stronger signal. > > Maybe you can detect something of that 5.755 kHz transmission. > > 73,GL, Stefan/DK7FC > > > > BTW Today I have updated SpecLab from version 2.79 b08 to b10 (Jan 26), > and it seems that GPS 1-pps sync is finally working well now, even with 4= 2 > =B5Hz resolution. > > Good luck for the test! > > 73, Markus (DF6NM) > > > > > *From:* Stefan Sch=E4fer > *Sent:* Saturday, February 01, 2014 5:46 PM > *To:* rsgb_lf_group@blacksheep.org > *Subject:* LF: DXl VLF experiments in 3HD > > VLF, > > This evening and night i'm planning to transmit on *5.755 kHz*, using the > large antenna, the large coil and the large PA :-) > I don't know what can be expected and how the system works at that > frequency. Actually it is just *a first test for playing arround and > doing some measurements* :-) > If some nearby stations want to give it a try, maybe even in *3HD*, then > don't hesitate :-) > > 73, Stefan/DK7FC > > --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk https://sites.google.com/site/sub9khz/ http://qss2.blogspot.com/ http://www.youtube.com/user/g3xbm --001a11c29512c9ea2204f16db550 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
With 420uHz or 47uHz BW could be very reada= ble with Marcus.

73s
Roger G3XBM


On 2 February 2014= 14:27, Stefan Sch=E4fer <Stefan.Schaefer@iup.uni-heid= elberg.de> wrote:
=20
Markus,

I am 16 dB stronger now!


Am 02.02.2014 14:52, schrieb Markus Vester:
=20 =20 =20
So what=A0should be expected here?=A0Scaling the fieldstrength from 1 km to 180 km (1/r^3 to lambda/2/pi, 1/r thereafter),=A0the signal should be=A082 dB=A0weaker here = on 5.755, and=A063 dB weaker on 17.265 kHz.=A0Negl= ecting ionospheric contributions (not really correct),=A0and assuming similar noise levels (though 5.5 kHz=A0is much affected by railway QRM here), my SNR in 0.47mHz should theoretically have been=A0
=A035 - 82 + 10 dB =3D -37 dB on 5 kHz and
=A050 - 63 + 10 dB =3D -3 dB on 17 kHz.<= /div>
So while a detection on the fundamental seems pretty hopeless, the third harmonic should already be getting close.
Yes, the QRN and QRM is much lower in 3HD :-) Why didn't we get this idea earlier???


=A0What is the inductance of=A0the loading coil?
Ehm , i didn't really measured it, it's just trial and error.


Would be interesting to see a picture of the scope trace picked up near the antenna ;-)
Looks quite good but could cause misunderstandings...

The amperemeter in the coil shows 350 mA now! There is some kind of selfoscillations, audible. Thus i do not rise the power even more. Have to search, find and fix this problem later. The AC voltage from the vari-transformer is 110V now, so there is room for at least another 6 dB. Power is in the range of 100W now.

I'm going to measure the strength at home now. Hopefully the signal is audible :-) Yesterday it was still weaker than the mains hum, so far away from any interferences!

73, Stefan


=A0
Best 73,
Markus (DF6NM)
=A0

Sent: Sunday, February 02, 2014 2:06 PM
Subject: Re: LF: DX VLF experiments in 3HD

Markus, VLF,

Am 01.02.2014 20:34, schrieb Markus Vester:
=20
Stefan,
=A0
running two 478 =B5Hz "6000" window= s centered on 5755 Hz (on the grabber, but much QRM here) and also 17265 Hz (offline) which seems more quiet. So hoping for a long carrier...=
Well, i hope that 16 hours key down were long enough ;-)

On which of the two frequencies would you expect to=A0radiate more power?
I don't know. But the harmonic signal is very weak and cannot cause interferences for JXN or HWU or SAQ or GBZ...

I've done measurements at home, 950m distance, of that 5.755 kHz transmission and saw that the signal was very weak, see attachment. Just 50 dB SNR in 4.5 mHz at 3HD. The TX power was just 15W at the end. Also the frequency response of the active antenna + soundcard is attached.

The experiments are very interesting here and i like to do the measurements. Despite rain the coil was on the top of the building and on air. It was just covered by a trash bag. The voltages are very small...
I just hang out a 30cm long wire connected to a probe of the oscilloscope and so the voltage waveform of the antenna wire. It nearly looks as expected :-)

Now i got another idea. There is a 2.2 uF WIMA MKP-10 capacitor in series to the output of the H bridge, just to protect it against damage in case of a DC output. Now i've disconnected the antenna and tuned for the series resonance of this C and the L of the primary winding of the loading coil. The resonance is at 1.77 kHz. This allowed me to calculate a much smaller additional series C which helps to attenuate unwanted frequency components, i.e. makes the spectrum cleaner and provides a lower impedance on the wanted frequency :-)

There is really no alternative to that H bride PA which works from 10 Hz to 100 kHz :-)

in a few minutes i will be on air again for a longer time, hopefully with a much stronger signal.

Maybe you can detect something of that 5.755 kHz transmission.

73,GL, Stefan/DK7FC


=A0
BTW Today I have updated SpecLab from version 2.79 b08 to b10 (Jan 26), and it seems that=A0GPS 1-pps sync is finally working well now, even=A0with=A042 =B5Hz resolution.
=A0
Good luck for the test!
=A0
73, Markus (DF6NM= )
=A0
=A0
=A0

Sent: Saturday, February 01, 2014 5:46 PM
Subject: LF: DXl VLF experiments in 3HD

VLF,

This evening and night i'm planning to transmit on 5.755 kHz<= /u>, using the large antenna, the large coil and the large PA :-)
I don't know what can be expected and how the system works at that frequency. Actually it is just a first test for playing arround and doing some measurements :-)
If some nearby stations want to give it a try, maybe even in 3HD, then don't hesitate :-)

73, Stefan/DK7FC



--
--001a11c29512c9ea2204f16db550--