Delivered-To: daveyxm@virginmedia.com Received: by 10.50.237.98 with SMTP id vb2csp72936igc; Sun, 2 Feb 2014 06:32:52 -0800 (PST) X-Received: by 10.180.96.228 with SMTP id dv4mr5621971wib.24.1391351572319; Sun, 02 Feb 2014 06:32:52 -0800 (PST) Return-Path: Received: from post.thorcom.com (post.thorcom.com. [195.171.43.25]) by mx.google.com with ESMTP id em8si8446440wjd.147.2014.02.02.06.32.51 for ; Sun, 02 Feb 2014 06:32:52 -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=@mx.aol.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1W9xT8-0007Io-Fp for rs_out_1@blacksheep.org; Sun, 02 Feb 2014 13:52:18 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1W9xT7-0007If-Qi for rsgb_lf_group@blacksheep.org; Sun, 02 Feb 2014 13:52:17 +0000 Received: from omr-m10.mx.aol.com ([64.12.143.86]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1W9xT4-00060M-Rr for rsgb_lf_group@blacksheep.org; Sun, 02 Feb 2014 13:52:16 +0000 Received: from mtaout-mbb02.mx.aol.com (mtaout-mbb02.mx.aol.com [172.26.254.110]) by omr-m10.mx.aol.com (Outbound Mail Relay) with ESMTP id 3781C701F91F1 for ; Sun, 2 Feb 2014 08:52:12 -0500 (EST) Received: from White (95-91-237-152-dynip.superkabel.de [95.91.237.152]) by mtaout-mbb02.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 3F82D38000083 for ; Sun, 2 Feb 2014 08:52:09 -0500 (EST) Message-ID: <5A61157818CE4049A4ABE989EBD7AE5C@White> 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> Date: Sun, 2 Feb 2014 14:52:07 +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=1391349132; bh=z2kaXEKrjYAg5OiJ1PBGWuRrXmgryXhPxK5L4+mCz3M=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=yOg3Q9yONL6ocJKMVT9QZSE+DoKbu50szAXBDY8NrLXGm6d/3PNRPHfa7AkJNWySu lSTBx/VSRDewr4EVLj3Hl+7B1FI2JcNt/6qiRH1L1gLXAhpVhHFPx2S+fpRN++EdWK mBTl87SDB3Lg2vcSMnMREbKTnSM2hE9XfOzrmFwg= x-aol-sid: 3039ac1afe6e52ee4d892842 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, unfortunately nothing was detected here, neither on http://dl.dropboxusercontent.com/u/26404526/vlf_5k755_140202_1100.png nor http://dl.dropboxusercontent.com/u/26404526/vlf_17k265_140202_0932.png. [...] 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 [64.12.143.86 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: 62fc2827c05a630837daa4729d9cda83 Subject: Re: LF: DX VLF experiments in 3HD Content-Type: multipart/alternative; boundary="----=_NextPart_000_0018_01CF2026.58036FA0" 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_0018_01CF2026.58036FA0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Stefan, unfortunately nothing was detected here, neither on=20 http://dl.dropboxusercontent.com/u/26404526/vlf_5k755_140202_1100.png = nor=20 http://dl.dropboxusercontent.com/u/26404526/vlf_17k265_140202_0932.png. 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. What is the inductance of the loading coil? Would be interesting to see = a picture of the scope trace picked up near the antenna ;-) 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_0018_01CF2026.58036FA0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Stefan,
 
unfortunately nothing was detected = here, neither on=20
http://dl.dropboxusercontent.com/u/26404526/vlf_5k755_140202_1100.p= ng nor=20
http://dl.dropboxusercontent.com/u/26404526/vlf_17k265_140202_0932= .png.
 
So what should be expected = here? Scaling=20 the fieldstrength from 1 km to 180 km (1/r^3 to lambda/2/pi, 1/r=20 thereafter), the signal should be 82 dB weaker here on = 5.755,=20 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=20 kHz.
So while a detection on the fundamental = seems=20 pretty hopeless, the third harmonic should already be getting=20 close.
 
What is the inductance of the = loading coil?=20 Would be interesting to see a picture of the scope trace picked up near = the=20 antenna ;-)
 
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=20 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) which=20 seems more quiet. So hoping for a long = carrier...
Well,=20 i hope that 16 hours key down were long enough ;-)

On which of the two frequencies would = you expect=20 to radiate more power?
I don't know. But = the=20 harmonic signal is very weak and cannot cause interferences for JXN or = HWU or=20 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 = 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 the=20 measurements. Despite rain the coil was on the top of the building and = on air.=20 It was just covered by a trash bag. The voltages are very small...
I = just=20 hang out a 30cm long wire connected to a probe of the oscilloscope and = so the=20 voltage waveform of the antenna wire. It nearly looks as expected = :-)

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

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

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

Maybe you can detect something of = that 5.755=20 kHz 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 on=20 5.755 kHz, using the large antenna, the large coil and = the large=20 PA :-)
I don't know what can be expected and how the system works = at that=20 frequency. Actually it is just a first test for playing arround and = doing=20 some measurements :-)
If some nearby stations want to give it = a try,=20 maybe even in 3HD, then don't hesitate :-)

73,=20 Stefan/DK7FC
------=_NextPart_000_0018_01CF2026.58036FA0--