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[195.171.43.25]) by mx.google.com with ESMTP id dj2si8639393wjc.7.2014.02.02.09.47.52 for ; Sun, 02 Feb 2014 09:47:52 -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=@mx.aol.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1WA0di-0000G8-1V for rs_out_1@blacksheep.org; Sun, 02 Feb 2014 17:15:26 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1WA0dh-0000Fz-A7 for rsgb_lf_group@blacksheep.org; Sun, 02 Feb 2014 17:15:25 +0000 Received: from omr-d07.mx.aol.com ([205.188.109.204]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1WA0dd-0006hZ-Vv for rsgb_lf_group@blacksheep.org; Sun, 02 Feb 2014 17:15:24 +0000 Received: from mtaout-mca01.mx.aol.com (mtaout-mca01.mx.aol.com [172.26.221.77]) by omr-d07.mx.aol.com (Outbound Mail Relay) with ESMTP id DA3F5701C5850 for ; Sun, 2 Feb 2014 12:15:19 -0500 (EST) Received: from White (95-91-237-152-dynip.superkabel.de [95.91.237.152]) by mtaout-mca01.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id CC54C38000095 for ; Sun, 2 Feb 2014 12:15:16 -0500 (EST) Message-ID: From: "Markus Vester" To: 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 18:15:13 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 12.0.1606 X-MimeOLE: Produced By Microsoft MimeOLE V12.0.1606 x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1391361319; bh=G4pLfUkOKcj8EfEJucpCCSAlLQIoU8qt4DI9Er641NU=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=i+UrCETOckwfYETBeX1limhEwzv6X042Y9Z3DKpbYiH8MSJR5+YJJzQRvRNalllIc 1q0LAZt/mTq7V6nwYmyUrt+YON4/xgd0pDfwaNwttz9GxgfUSzQIyzUlJnv2cUcAHB Ciihyjtg5gd0uKNIJut2FkLgkHKcfaCyWW0K1a1s= x-aol-sid: 3039ac1add4d52ee7d242dee X-AOL-IP: 95.91.237.152 X-Spam-Score: -0.5 (/) 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: Stefan, your third harmonic is clearly visible in Holland http://www.qsl.net/pa1sdb/ and here http://www.df6nm.de/vlf/vlfgrabber.htm Started spot-on 17265 Hz, now another peak is coming up 15 mHz up. [...] Content analysis details: (-0.5 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [205.188.109.204 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.5 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 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: 1a92164900c4e119399f770c0cc93934 Subject: Re: LF: DX VLF experiments in 3HD Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01CF2042.B75C8CE0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.5 required=5.0 tests=HTML_30_40,HTML_MESSAGE, HTML_TITLE_EMPTY,MISSING_OUTLOOK_NAME 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 Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_0006_01CF2042.B75C8CE0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Stefan, your third harmonic is clearly visible in Holland http://www.qsl.net/pa1sdb/ and here http://www.df6nm.de/vlf/vlfgrabber.htm Started spot-on 17265 Hz, now another peak is coming up 15 mHz up. Good luck, Markus (DF6NM) From: Stefan Sch=E4fer=20 Sent: Sunday, February 02, 2014 3:27 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: DX VLF experiments in 3HD Markus,=20 I am 16 dB stronger now! Am 02.02.2014 14:52, schrieb Markus Vester:=20 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 = noise levels (though 5.5 kHz is much affected by railway QRM here), my = SNR in 0.47mHz should theoretically have been=20 35 - 82 + 10 dB =3D -37 dB on 5 kHz and=20 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 = 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 Best 73, Markus (DF6NM) From: Stefan Sch=E4fer=20 Sent: Sunday, February 02, 2014 2:06 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: DX VLF experiments in 3HD Markus, VLF, Am 01.02.2014 20:34, schrieb Markus Vester:=20 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 = 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 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 42 =B5Hz resolution. Good luck for the test! 73, Markus (DF6NM) From: Stefan Sch=E4fer=20 Sent: Saturday, February 01, 2014 5:46 PM To: rsgb_lf_group@blacksheep.org=20 Subject: LF: DXl VLF experiments in 3HD VLF,=20 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 :-)=20 If some nearby stations want to give it a try, maybe even in 3HD, = then don't hesitate :-) 73, Stefan/DK7FC ------=_NextPart_000_0006_01CF2042.B75C8CE0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Stefan,
 
your third harmonic is clearly visible = in=20 Holland
http://www.qsl.net/pa1sdb/=
and here
http://www.df6nm.de/vlf/v= lfgrabber.htm
 
Started spot-on 17265 Hz, now another = peak is=20 coming up 15 mHz up.
 
Good luck,
Markus (DF6NM)
 

From: Stefan = Sch=E4fer
Sent: Sunday, February 02, 2014 3:27 PM
Subject: Re: LF: DX VLF experiments in 3HD

Markus,

I am 16 dB stronger now!


Am = 02.02.2014=20 14:52, schrieb Markus Vester:=20
So what should be expected=20 here? Scaling the fieldstrength from 1 km to 180 km (1/r^3 to=20 lambda/2/pi, 1/r thereafter), the signal should be 82 = dB weaker=20 here on 5.755, and 63 dB weaker on 17.265 kHz. Neglecting ionospheric contributions (not really = correct), and=20 assuming similar noise levels (though 5.5 kHz is much affected by = railway=20 QRM here), my SNR in 0.47mHz should theoretically have = been 
 35 - 82 + 10 dB =3D -37 dB on 5 = kHz and=20
 50 - 63 + 10 dB =3D -3 dB on 17 = kHz.
So while a detection on the = fundamental seems=20 pretty hopeless, the third harmonic should already be getting=20 close.
Yes, the QRN and QRM is much lower in = 3HD :-)=20 Why didn't we get this idea earlier???

 What is the inductance = of the loading=20 coil?
Ehm , i didn't really measured it, it's = just=20 trial and error.

Would be interesting to see a picture = of the=20 scope trace picked up near the antenna = ;-)
Looks quite=20 good but could cause misunderstandings...

The amperemeter in the = coil=20 shows 350 mA now! There is some kind of selfoscillations, audible. Thus = i do not=20 rise the power even more. Have to search, find and fix this problem = later. The=20 AC voltage from the vari-transformer is 110V now, so there is room for = at least=20 another 6 dB. Power is in the range of 100W now.

I'm going to = measure the=20 strength at home now. Hopefully the signal is audible :-) Yesterday it = was still=20 weaker than the mains hum, so far away from any = interferences!

73,=20 Stefan

 
Best 73,
Markus (DF6NM)
 

From: Stefan Sch=E4fer
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,
 
running two 478 =B5Hz "6000" = windows centered on=20 5755 Hz (on the grabber, but much QRM here) and also 17265 Hz = (offline)=20 which seems more quiet. So hoping for a long=20 carrier...
Well, i hope that 16 hours key = down were=20 long enough ;-)

On which of the two frequencies = would you=20 expect to radiate more power?
I don't = know. But=20 the harmonic signal is very weak and cannot cause interferences for = JXN or HWU=20 or SAQ or GBZ...

I've done measurements at home, 950m distance, = of that=20 5.755 kHz transmission and saw that the signal was very weak, = see=20 attachment. Just 50 dB SNR in 4.5 mHz at 3HD. The TX power was just = 15W at the=20 end. Also the frequency response of the active antenna + soundcard is=20 attached.

The experiments are very interesting here and i like = to do=20 the measurements. Despite rain the coil was on the top of the building = and on=20 air. It was just covered by a trash bag. The voltages are very = small...
I=20 just hang out a 30cm long wire connected to a probe of the = oscilloscope and so=20 the voltage waveform of the antenna wire. It nearly looks as expected=20 :-)

Now i got another idea. There is a 2.2 uF WIMA MKP-10 = capacitor in=20 series to the output of the H bridge, just to protect it against = damage in=20 case of a DC output. Now i've disconnected the antenna and tuned for = the=20 series resonance of this C and the L of the primary winding of the = loading=20 coil. The resonance is at 1.77 kHz. This allowed me to calculate a = much=20 smaller additional series C which helps to attenuate unwanted = frequency=20 components, i.e. makes the spectrum cleaner and provides a lower = impedance on=20 the wanted frequency :-)

There is really no alternative to that = H bride=20 PA which works from 10 Hz to 100 kHz :-)

in a few minutes i = will be on=20 air again for a longer time, hopefully with a much stronger=20 signal.

Maybe you can detect something of that 5.755 kHz=20 transmission.

73,GL, Stefan/DK7FC


 
BTW Today I have updated SpecLab = from version=20 2.79 b08 to b10 (Jan 26), and it seems that GPS 1-pps sync is = finally=20 working well now, even with 42 =B5Hz = resolution.
 
Good luck for the = test!
 
73, Markus=20 (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=20 on 5.755 kHz, using the large antenna, the large coil = and the=20 large PA :-)
I don't know what can be expected and how the system = works=20 at that frequency. Actually it is just a first test for playing = arround=20 and doing some measurements :-)
If some nearby stations want = to give=20 it a try, maybe even in 3HD, then don't hesitate = :-)

73,=20 Stefan/DK7FC
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