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: dcc1: mailn 1182; 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 v4NALY2A031414 for ; Tue, 23 May 2017 12:21:35 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1dD6sw-0000u6-2d for rs_out_1@blacksheep.org; Tue, 23 May 2017 11:17:50 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1dD6sv-0000ts-Fq for rsgb_lf_group@blacksheep.org; Tue, 23 May 2017 11:17:49 +0100 Received: from omr-a004e.mx.aol.com ([204.29.186.52]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.89) (envelope-from ) id 1dD6sr-0002eF-Jx for rsgb_lf_group@blacksheep.org; Tue, 23 May 2017 11:17:48 +0100 Received: from mtaomg-aaj02.mx.aol.com (mtaomg-aaj02.mx.aol.com [172.27.3.208]) by omr-a004e.mx.aol.com (Outbound Mail Relay) with ESMTP id C3E8A38000AA for ; Tue, 23 May 2017 06:17:43 -0400 (EDT) Received: from core-ace07g.mail.aol.com (core-ace07.mail.aol.com [172.27.23.7]) by mtaomg-aaj02.mx.aol.com (OMAG/Core Interface) with ESMTP id 92DB738000082 for ; Tue, 23 May 2017 06:17:43 -0400 (EDT) Received: from 80.146.228.71 by webprd-a101.mail.aol.com (10.72.52.238) with HTTP (WebMailUI); Tue, 23 May 2017 06:17:43 -0400 Date: Tue, 23 May 2017 06:17:43 -0400 From: Markus Vester To: rsgb_lf_group@blacksheep.org Message-Id: <15c34cff573-117a-973a@webprd-a101.mail.aol.com> In-Reply-To: <59234B8F.6010903@posteo.de> MIME-Version: 1.0 X-MB-Message-Source: WebUI X-MB-Message-Type: User X-Mailer: JAS STD X-Originating-IP: [80.146.228.71] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20150623; t=1495534663; bh=1elSM6AJ+zgXvP+ARa3OA9tfbtrAmbfCVC70svIDyRQ=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=Ovm1hMa2IKBZ5BwxVxN7lyV50AglHhdehlxs4RA8sUn3W5lEBTw1pyxH7tl3ImxIm rzPWqaXXTwAlRMiuLPrn2qZjp4t0rNp5gN1UmZvCVfpPbRolSQssFkmVuSxTYftgO8 I1fE/8dGFzzx/8W7cHN2FpDgsbEWXfkaxoBvua8U= x-aol-sid: 3039ac1b03d059240c47134e X-Scan-Signature: f0da950ecedac2a84ae70831926f1b39 Subject: Re: ULF: New experiment on 970 Hz, 2/3 Content-Type: multipart/alternative; boundary="----=_Part_45903_1277133669.1495534663026" 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: X-Keywords: X-UID: 11732 ------=_Part_45903_1277133669.1495534663026 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hi Stefan, the screenshot generally looks good. There are some 50 Hz harmonics as well= as modulated 33 Hz harmonics but neither seems to contaminate the desired = frequency range around 9.70 hectoHz. However to my eyes, the nighttime spherics seem to be much stronger at low = frequency (< 1.2 kHz) than I had expected, though I have to say I'm not at = all sure whether that should be so or not. I would speculate that they coul= d be artifacts from higher frequency spherics energy, which may be AM-demod= ulated by some quadratic nonlinearity in the receive circuitry (e.g. the FE= T at the input), producing a low-frequency envelope component.=20 You could check this in a benchtop measurement by feeding a two-tone signal= (e.g. 5 and 5.5 kHz, with PEP level approximating that of the strongest sp= herics) to the receiver, and measuring second-order intermodulation (IM2) a= t the 500 Hz difference frequency. If this indeed turns out to be significa= nt, you could possibly improve your recording a posteriori by subtracting a= n appropriately weighted squared signal component. Perhaps this could even = be done on the fly using SpecLab's built-in multiplier and adder functions. Best regards, Markus (DF6NM) -----Urspr=C3=BCngliche Mitteilung-----=20 Von: DK7FC An: rsgb_lf_group Cc: Renato Romero ; =D0=90=D0=BD=D0=B4=D1=80=D0=B5=D0=B9 = =D0=9A=D0=BB=D0=B8=D0=BC=D0=BE=D0=B2 Verschickt: Mo, 22. Mai 2017 22:37 Betreff: Re: ULF: New experiment on 970 Hz, 2/3 Hi ULF,=20 So far the recent 970 Hz experiment went very well: -The transmissions were done as planned. I slightly modified the transmiss= ion plan and sent 2 EbNaut messages. The TX was running almost 4 days witho= ut interruptions, despite the heavy rain and local thunderstorms. -When coming back to the RX site, everything was in its right place. The 4= x 7 Ah lead gel accus were discharged to 12.1 V only. The recording process= was still running.=20 -I have now a 30 GB .dat file on the USB stick. This file will be analysed= in the coming days. I hope to extract a clear carrier and maybe even decod= e the EbNaut messages? A first image showing the 0...3 kHz spectrum without filters and blanker: = https://www.dropbox.com/s/26bbkfb8q0hs20h/First%20two%20days%20from%20the%2= 0recording.%20No%20filters%20and%20blankers.png?dl=3D0 (there is a bug on t= he timescale) Does this look normal for the experts? Any comments/ideas? Unfortunately there was a microphonic effect on the E field antenne. I can= hear bumblebees from time to time!! ;-) 73, Stefan Am 17.05.2017 12:07, schrieb DK7FC:=20 Hi all,=20 Yesterday it was a perfect day here, sunny all the time, about 26 =C2=B0C,= the forests have a fresh green :-) ...and i put a ULF E-field RX somewhere= into JN49LN :-) It will record about 4 days at 24 kS/s. It is the next experiment on the 309 km band. Since 16.May.2017 a plain ca= rrier is running on 970.005 Hz. I'm again using the modified mains transfor= mer which generates just 5 kV on the antenna. In SpecLab i'm keeping 15 mA = antenna current constant, as well as the phase of the signal. That results = in an ERP of about 3 nW. The active E field probe is a 1m vertical and 3m horizontal wire, lifted a= bout 10m above ground. The attempt is to reach a 27 km distance! First i searched for a 25 km dis= tant location but when i arrived there, there were loads of electrical fenc= es.=20 In the new location i took a short recording which can be analysed now. Th= e spectrum contains relatively high levels of mains hum, but all in all it = looks fine. So far the QRN levels are relatively low, which is good. I made a few adjustments to the receiver, hopefully it performs nicely.=20 I expect maybe a very faint trace in 424 uHz when QRN is low but it should= be a clear trace in 47 uHz. The transmission plan is to keep the carrier on the air until midnight, i.= e. 33 hours for the carrier. Then Thursday 0 UTC an EbNaut message (N=3D5, = CRC=3D4, 100s, 16K21A , 24:00:00 hh:mm:ss) will start at 970.005 Hz. Friday= and Saturday will be for a carrier at 970.0025 Hz. So far the carrier runs very well. Hopefully it will be a successful exper= iment again :-) 73, Stefan ------=_Part_45903_1277133669.1495534663026 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Hi Stefan,

the screenshot generally= looks good. There are some 50 Hz harmonics as well as modulated 33 Hz harm= onics but neither seems to contaminate the desired frequency range around 9= .70 hectoHz.

However to my eyes, the nighttime spheric= s seem to be much stronger at low frequency (< 1.2 kHz) than I had expec= ted, though I have to say I'm not at all sure whether that should be so or = not. I would speculate that they could be artifacts from higher frequency s= pherics energy, which may be AM-demodulated by some quadratic nonlinearity = in the receive circuitry (e.g. the FET at the input), producing a low-frequ= ency envelope component.

You could check this in a be= nchtop measurement by feeding a two-tone signal (e.g. 5 and 5.5 kHz, with P= EP level approximating that of the strongest spherics) to the receiver, and= measuring second-order intermodulation (IM2) at the 500 Hz difference freq= uency. If this indeed turns out to be significant, you could possibly impro= ve your recording a posteriori by subtracting an appropriately weighted squ= ared signal component. Perhaps this could even be done on the fly using Spe= cLab's built-in multiplier and adder functions.

Best r= egards,
Markus (DF6NM)


-----Urspr=C3=BCngliche = Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_l= f_group <rsgb_lf_group@blacksheep.org>
Cc: Renato Romero <conta= ct@vlf.it>; =D0=90=D0=BD=D0=B4=D1=80=D0=B5=D0=B9 =D0=9A=D0=BB=D0=B8=D0= =BC=D0=BE=D0=B2 <rd4hu@MAIL.ru>
Verschickt: Mo, 22. Mai 2017 22:37=
Betreff: Re: ULF: New experiment on 970 Hz, 2/3

Hi ULF,

So far the recent 970 Hz experiment went very well:

-The transmissions were done as planned. I slightly modified the transmission plan and sent 2 EbNaut messages. The TX was running almost 4 days without interruptions, despite the heavy rain and local thunderstorms.
-When coming back to the RX site, everything was in its right place. The 4x 7 Ah lead gel accus were discharged to 12.1 V only. The recording process was still running.
-I have now a 30 GB .dat file on the USB stick. This file will be analysed in the coming days. I hope to extract a clear carrier and maybe even decode the EbNaut messages?

A first image showing the 0...3 kHz spectrum without filters and blanker: https://www.dropbox.com/s/26bbkfb8q0hs20h/First%20two%20days%20from%20th= e%20recording.%20No%20filters%20and%20blankers.png?dl=3D0 (there is a bug on the timescale)

Does this look normal for the experts? Any comments/ideas?
Unfortunately there was a microphonic effect on the E field antenne. I can hear bumblebees from time to time!! ;-)

73, Stefan




Am 17.05.2017 12:07, schrieb DK7FC:
=20 Hi all,

Yesterday it was a perfect day here, sunny all the time, about 26 =C2=B0C, the forests have a fresh green :-) ...and i put a ULF E-field RX somewhere into JN49LN :-) It will record about 4 days at 24 kS/s.
It is the next experiment on the 309 km band. Since 16.May.2017 a plain carrier is running on 970.005 Hz. I'm again using the modified mains transformer which generates just 5 kV on the antenna. In SpecLab i'm keeping 15 mA antenna current constant, as well as the phase of the signal. That results in an ERP of about 3 nW.

The active E field probe is a 1m vertical and 3m horizontal wire, lifted about 10m above ground.
The attempt is to reach a 27 km distance! First i searched for a 25 km distant location but when i arrived there, there were loads of electrical fences.
In the new location i took a short recording which can be analysed now. The spectrum contains relatively high levels of mains hum, but all in all it looks fine.
So far the QRN levels are relatively low, which is good.
I made a few adjustments to the receiver, hopefully it performs nicely.

I expect maybe a very faint trace in 424 uHz when QRN is low but it should be a clear trace in 47 uHz.

The transmission plan is to keep the carrier on the air until midnight, i.e. 33 hours for the carrier. Then Thursday 0 UTC an EbNaut message (N=3D5, CRC=3D4, 100s, 16K21A , 24:00:00 hh:mm:ss) will start at 970.005 Hz. Friday and Saturday will be for a carrier at 970.0025 Hz.

So far the carrier runs very well. Hopefully it will be a successful experiment again :-)

73, Stefan
------=_Part_45903_1277133669.1495534663026--