Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,RCVD_IN_DNSWL_MED, SPF_PASS,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: MGTINTERNET: mailn 1170; Body=2 Fuz1=2 Fuz2=2 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v3OKjJMI000804 for ; Mon, 24 Apr 2017 22:45:20 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1d2kmZ-0000ZF-9d for rs_out_1@blacksheep.org; Mon, 24 Apr 2017 21:40:27 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1d2kmY-0000Z6-EG for rsgb_lf_group@blacksheep.org; Mon, 24 Apr 2017 21:40:26 +0100 Received: from omr-a007e.mx.aol.com ([204.29.186.58]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.89) (envelope-from ) id 1d2kmT-00031J-KU for rsgb_lf_group@blacksheep.org; Mon, 24 Apr 2017 21:40:25 +0100 Received: from mtaomg-mae01.mx.aol.com (mtaomg-mae01.mx.aol.com [172.26.254.143]) by omr-a007e.mx.aol.com (Outbound Mail Relay) with ESMTP id A52B13800075 for ; Mon, 24 Apr 2017 16:40:19 -0400 (EDT) Received: from core-acc05f.mail.aol.com (core-acc05.mail.aol.com [172.26.125.15]) by mtaomg-mae01.mx.aol.com (OMAG/Core Interface) with ESMTP id 4175938000083 for ; Mon, 24 Apr 2017 16:40:19 -0400 (EDT) Received: from 188.192.95.60 by webprd-a70.mail.aol.com (10.72.57.78) with HTTP (WebMailUI); Mon, 24 Apr 2017 16:40:19 -0400 Date: Mon, 24 Apr 2017 16:40:19 -0400 From: Markus Vester To: rsgb_lf_group@blacksheep.org Message-Id: <15ba1b18b60-4ff-30c3d@webprd-a70.mail.aol.com> In-Reply-To: MIME-Version: 1.0 X-MB-Message-Source: WebUI X-MB-Message-Type: User X-Mailer: JAS STD X-Originating-IP: [188.192.95.60] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20150623; t=1493066419; bh=1hIYkTnZjzE6jcKbca2WqpQ+M3g3oDGwW73cQWo/iag=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=8iMjuwIowqDr0g/sc3+W8xe8fuCAxxsMc/IxLi85Vh0a7joUuMn2NlFVlaj8pPwND yznBaNqVxkNYZrlyhw2ZW9yDEkOxP/UZoyWSR5dRHJh/6X67v201VFOcds1KeFvFtr 2+XUWdtBFPgi1ayX93usXYRh8d3JijjBc0pQuAfc= x-aol-sid: 3039ac1afe8f58fe62b359a6 X-Scan-Signature: 7a302ec14fb4a62f16f049454b6dc54d Subject: Re: LF: Re[2]: VLF: New carrier on 6470.005 Hz Content-Type: multipart/alternative; boundary="----=_Part_239909_955832331.1493066419035" 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-Scanned-By: MIMEDefang 2.75 Status: RO X-Status: A X-Keywords: X-UID: 11476 ------=_Part_239909_955832331.1493066419035 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hi Jacek, in my case, the vast deficit on 6.47 kHz reception is clearly due to QRM fr= om nearby railway lines. On http://df6nm.bplaced.net/VLF/screenshots/vlfwid= e_170422_1200.jpg , you can see two violet packs of unstable 33 Hz spaced l= ines, one around 3 kHz and the other above 6 kHz (note that they are strong= er than they appear because the antenna ferquency response already rolls of= f below 8 kHz). I am trying to mitigate the interference by tracking the ca= rriers with SpecLab's automatic multinotch filter, but with limited success= . Looking at the excellent stability even at higher-frequencies, I'm pretty s= ure that SpecLab's 1pps processing is reasonably precise. In my narrowband = instances, the noise blanker is preceeded by a 3.5 kHz wide Bessel bandpass= with low ringing, covering both 6 and 8 kHz bands. On one occasion, the DL0AO receiver in Amberg had produced a marginal 6.47 = kHz two-character EbNaut decode. But they are still using various improvise= d antennas until a proper VLF receive antenna will be ready. I was actually hoping for better results because Stefan's good reception of= my 6.47 kHz carrier proved that daytime propagation at our distance is str= onger (in relation to ERP) and more stable than at 8.27 kHz. Best 73, Markus (DF6NM) -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Jacek Lipkowski An: rsgb_lf_group Verschickt: Mo, 24. Apr 2017 17:10 Betreff: Re: LF: Re[2]: VLF: New carrier on 6470.005 Hz Paul receives anything (as usual). But the strange thing is that i can=20 receive the 6470Hz signal with a mediocre setup (suboptimal antenna, qrm=20 location in the center of Warsaw) at 900km, while Eddie (at 750km=20 distance) and especially Markus (at 180km) can't receive. The only other explanation (apart from lower qrm levels) might be the=20 software used. I use Paul's vlfrx-tools, while Eddie and Markus use=20 Spectrum Lab. The obvious differences are: - gps timing (edge in speclab vs "stretched pulse" magic in=20 vlfrx-tools). not sure what impact this may have - noise blanker. most speclab setups use the noiseblanker on the whole=20 spectrum (haven't seen your setup, but this is what most example=20 configrations i've seen do), while the vlfrx-tools/ebnaut examples use the= =20 noiseblanker only on a 3kHz bandwidth segment centered around the rx=20 frequency (this could be done with speclab easily too). also the speclab=20 noiseblanker algorithm might be a bit different Maybe try vlfrx-tools and see if there is any difference? And if so,=20 tweak speclab to do the same (especially the filtering/noiseblanker=20 should be simple) VY 73 Jacek / SQ5BPF On Mon, 24 Apr 2017, DK7FC wrote: > Date: Mon, 24 Apr 2017 15:18:45 +0200 > From: DK7FC > Reply-To: rsgb_lf_group@blacksheep.org > To: rsgb_lf_group@blacksheep.org > Subject: Re: LF: Re[2]: VLF: New carrier on 6470.005 Hz >=20 > Hello Markus, Eddie, Paul, >=20 > Thanks for the feedback, for trying and for the results. > Very strange. Paul has excellent results (as usual) but no decode for Edd= ie. On > 8270 Hz, the 'difference' is much less expressed. Does it have to do with= local > QRM only? Maybe... > Maybe Alex has detected something. >=20 > Pauls results are particularly interesting. 1+1 =3D 1 * 2 =3D 3 dB. Prove= s the theory > :-) >=20 > The stacking would help to solve the problems it seems :-) A tool is need= ed... >=20 > 73, Stefan >=20 >=20 >=20 >=20 > Am 23.04.2017 23:24, schrieb Markus Vester: > Hi Stefan, > I tried to receive your message on both days, and even added the two > recordings with equal weight, but unfortunately no decode. Guess I need a > railway strike :-( > Unfortunately no luck from DL0AO data either. >=20 > Best 73, > Markus >=20 >=20 > -----Urspr=C3=BCngliche Mitteilung----- > Von: DK7FC > An: rsgb_lf_group > Verschickt: So, 23. Apr 2017 0:42 > Betreff: Re: LF: Re[2]: VLF: New carrier on 6470.005 Hz >=20 > Hi VLF, >=20 > another chance, the same msssage two hours earlier, improved timing towar= ds > the east... >=20 >=20 > f =3D 6470.100000 Hz > Start time: 23.Apr.2017 05:00:00 UTC > Symbol period: 40 s > Characters: 2 > CRC bits: 32 > Coding 16K21A > Duration: 11h, 22m, 40s > Antenna current: 460 mA >=20 >=20 > 73, Stefan >=20 >=20 > ------=_Part_239909_955832331.1493066419035 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Hi Jacek,

in my case, the vast deficit on 6.47 kH= z reception is clearly due to QRM from nearby railway lines. On http:/= /df6nm.bplaced.net/VLF/screenshots/vlfwide_170422_1200.jpg , you can see&nb= sp;two violet packs of unstable 33 Hz spaced lines, one around 3 = kHz and the other above 6 kHz (note that they are stronger than&n= bsp;they appear because the antenna ferquency response already ro= lls off below 8 kHz). I am trying to mitigate the interference by trac= king the carriers with SpecLab's automatic multinotch filter, but= with limited success.

Looking at the excellent stability even at hi= gher-frequencies, I'm pretty sure that SpecLab's 1pps processing is re= asonably precise. In my narrowband instances, the noise blanker is pre= ceeded by a 3.5 kHz wide Bessel bandpass with low ringing, covering both 6 = and 8 kHz bands.

On one occasion, the DL0AO receiver in Am= berg had produced a marginal 6.47 kHz two-character EbNaut decode. But they= are still using various improvised antennas until a proper VLF r= eceive antenna will be ready.

I was actually hoping for better resul= ts because Stefan's good reception of my 6.47 kHz carrier proved that dayti= me propagation at our distance is stronger (in relation to ERP) and mo= re stable than at 8.27 kHz.

Best 73,
Markus (DF6NM)

<= br>-----Urspr=C3=BCngliche Mitteilung-----
Von: Jacek Lipkowski <sq5= bpf@lipkowski.org>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org= >
Verschickt: Mo, 24. Apr 2017 17:10
Betreff: Re: LF: Re[2]: VLF: = New carrier on 6470.005 Hz

Paul receives anything (as usual). = But the strange thing is that i can
receive the 6470Hz signal with a me= diocre setup (suboptimal antenna, qrm
location in the center of Warsaw)= at 900km, while Eddie (at 750km
distance) and especially Markus (at 18= 0km) can't receive.

The only other explanation (apart from lower qrm= levels) might be the
software used. I use Paul's vlfrx-tools, while Ed= die and Markus use
Spectrum Lab. The obvious differences are:

- = gps timing (edge in speclab vs "stretched pulse" magic in
vlfrx-tools).= not sure what impact this may have

- noise blanker. most speclab se= tups use the noiseblanker on the whole
spectrum (haven't seen your setu= p, but this is what most example
configrations i've seen do), while the= vlfrx-tools/ebnaut examples use the
noiseblanker only on a 3kHz bandwi= dth segment centered around the rx
frequency (this could be done with s= peclab easily too). also the speclab
noiseblanker algorithm might be a = bit different

Maybe try vlfrx-tools and see if there is any differen= ce? And if so,
tweak speclab to do the same (especially the filtering/n= oiseblanker
should be simple)

VY 73

Jacek / SQ5BPF

On Mon, 24 Apr 2017, DK7FC wrote:

> Date: Mon, 24 Apr 2017 1= 5:18:45 +0200
> From: DK7FC <selberdenken@posteo.de>
> Reply-To: rsgb_lf_group@blacksheep.org
> To: rsgb_lf_group@blacksheep.org
> Subject: Re: LF: Re[2]: VLF: New carrier on 6470.005 Hz
> =
> Hello Markus, Eddie, Paul,
>
> Thanks for the feedbac= k, for trying and for the results.
> Very strange. Paul has excellent= results (as usual) but no decode for Eddie. On
> 8270 Hz, the 'diffe= rence' is much less expressed. Does it have to do with local
> QRM on= ly? Maybe...
> Maybe Alex has detected something.
>
> Pa= uls results are particularly interesting. 1+1 =3D 1 * 2 =3D 3 dB. Proves th= e theory
> :-)
>
> The stacking would help to solve the = problems it seems :-) A tool is needed...
>
> 73, Stefan
&g= t;
>
>
>
> Am 23.04.2017 23:24, schrieb Markus = Vester:
> Hi Stefan,
> I tried to receive your message on= both days, and even added the two
> recordings with equal weight, bu= t unfortunately no decode. Guess I need a
> railway strike :-(
>= ; Unfortunately no luck from DL0AO data either.
>
> Best 73,> Markus
>
>
> -----Urspr=C3=BCngliche Mitteilung-= ----
> Von: DK7FC <selbe= rdenken@posteo.de>
> An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
> V= erschickt: So, 23. Apr 2017 0:42
> Betreff: Re: LF: Re[2]: VLF: New c= arrier on 6470.005 Hz
>
> Hi VLF,
>
> another cha= nce, the same msssage two hours earlier, improved timing towards
> th= e east...
>
>
> f =3D 6470.100000 Hz
> Start time= : 23.Apr.2017   05:00:00 UTC
> Symbol period: 40 s
> Chara= cters: 2
> CRC bits: 32
> Coding 16K21A
> Duration: 11h, = 22m, 40s
> Antenna current: 460 mA
>
>
> 73, Stef= an
>
>
>
------=_Part_239909_955832331.1493066419035--