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: : mailn 1480; 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 v3SLEevl025166 for ; Fri, 28 Apr 2017 23:14:41 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1d4DAJ-0001y2-S5 for rs_out_1@blacksheep.org; Fri, 28 Apr 2017 22:10:59 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1d4DAJ-0001xt-3A for rsgb_lf_group@blacksheep.org; Fri, 28 Apr 2017 22:10:59 +0100 Received: from omr-a014e.mx.aol.com ([204.29.186.62]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.89) (envelope-from ) id 1d4DAE-0006Do-Dp for rsgb_lf_group@blacksheep.org; Fri, 28 Apr 2017 22:10:57 +0100 Received: from mtaomg-mab01.mx.aol.com (mtaomg-mab01.mx.aol.com [172.26.249.83]) by omr-a014e.mx.aol.com (Outbound Mail Relay) with ESMTP id 1BBF938000AD for ; Fri, 28 Apr 2017 17:10:52 -0400 (EDT) Received: from core-acb01f.mail.aol.com (core-acb01.mail.aol.com [172.27.24.1]) by mtaomg-mab01.mx.aol.com (OMAG/Core Interface) with ESMTP id BC19738000084 for ; Fri, 28 Apr 2017 17:10:51 -0400 (EDT) Received: from 188.192.95.60 by webprd-m107.mail.aol.com (10.74.63.49) with HTTP (WebMailUI); Fri, 28 Apr 2017 17:10:50 -0400 Date: Fri, 28 Apr 2017 17:10:50 -0400 From: Markus Vester To: rsgb_lf_group@blacksheep.org Message-Id: <15bb666ef1a-2379-cb5f@webprd-m107.mail.aol.com> In-Reply-To: <15bb6303397-2379-c8e6@webprd-m107.mail.aol.com> 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=1493413852; bh=NBG2RqgU6jfFsB8CWn48Hn+cmCeaBOopVDCAY3RbwTs=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=TWkYD3tzxSE505tIU13kKY0y2RsMdjbEKaglGj4b7fOP4ty44S36nfNiIbCtN3fmE L9Bzb6mmY0ZGz54GEpuLQmEkRUtyt97tfAFQcZAhFpRK+4A/GQAydNP3qhXesRlknC 4XzwOBFL+4PMQjKkKbCAw8M7fn3MUQ5Gmsbrizc8= x-aol-sid: 3039ac1af9535903afdb3a13 X-Scan-Signature: 0cdfd8d5ce44f1724c623c4ac9f44df6 Subject: Re: VLF: DK7FC 8270.005 and DF6NM 8270.005139 at DL0AO grabber Content-Type: multipart/alternative; boundary="----=_Part_65602_914498902.1493413850903" 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: 11510 ------=_Part_65602_914498902.1493413850903 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable The combined signal at DL0AO has been growing steadily during the last hour= , now at 21 UT we must be close to the maximum. For anyone who'd like to wa= tch it live, we'd like to announce an online VLF grabber in Amberg: http://df6nm.bplaced.net/dl0ao/VLFgrabber/vlfgrabber_dl0ao.htm The receive antenna is still an improvised long wire near a fence, but it s= eems to work quite well already. Tom and Bernd are building an active E.pro= be which will be installed soon. Best 73, Markus -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Markus Vester An: rsgb_lf_group Verschickt: Fr, 28. Apr 2017 22:11 Betreff: VLF: DK7FC 8270.005 and DF6NM 8270.005139 Around 17 UT, DK7FC has started another carrier on 8270.005 Hz. Since 20 UT= , I am joining in on a slightly higher frequency, 8270.005 + 1/7200 Hz (i.e= . 138.89 uHz up). Compared to Stefan, I can achieve about 60% current into = 60% effective antenna height, so my ERP should be ~ 9 dB weaker.=20 The two carriers will be resolved by a 47 uHz spectrogram. But at lower res= olution (e.g. 424 uHz), they will merge into a two-hour sinusoidal beat pat= tern. The idea is to use that to indirectly measure our phase difference, b= y observing the times of maxima and minima at DL0AO in Amberg (and perhaps = also in Paul's spectrogram). As both carriers are GPS locked, the two trans= mitters (or rather the two near-field pickup probe signals which are compar= ed to GPS) will be in phase at even hours (UT), and in antiphase at odd hou= rs. Using the known path difference (178 km =3D 4.9 lambda) to DL0AO, we co= uld in principle calibrate the phase difference of our differently built ph= ase-feedback probes. This could then be used in the future to obtain 2 to 3= dB directional gain in any desired direction. One shortcoming of the measurement may be that while the 48 km path from my= self to DL0AO is groundwave dominated, there will be a strong and variable = skywave contribution from DK7FC at 226 km. So any array steering calculated= therefrom may be incorrect during the daytime, or for long-distance paths = with skywave from both sources. It might however be possible to account for= the diurnal phase change using the DK7FC-DF6NM colour-phase measurement fr= om Jan 28/29. All the best, Markus (DF6NM) ------=_Part_65602_914498902.1493413850903 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
The combined signal at DL0AO has been growing steadily d= uring the last hour, now at 21 UT we must be close to the maximum. For anyo= ne who'd like to watch it live, we'd like to announce an online V= LF grabber in Amberg:

 http://df6nm.bplaced.net/dl0ao/VLFg= rabber/vlfgrabber_dl0ao.htm

The receive antenna is still an improvis= ed long wire near a fence, but it seems to work quite well already. Tom and= Bernd are building an active E.probe which will be installed soo= n.

Best 73,
Markus



-----Urspr=C3=BCngliche Mitteil= ung-----
Von: Markus Vester <markusvester@aol.com>
An: rsgb_lf= _group <rsgb_lf_group@blacksheep.org>
Verschickt: Fr, 28. Apr 2017= 22:11
Betreff: VLF: DK7FC 8270.005 and DF6NM 8270.005139

Around 17 UT, DK7FC = has started another carrier on 8270.005 Hz. Since 20 UT, I am joining in on= a slightly higher frequency, 8270.005 + 1/7200 Hz (i.e. 138.89 uHz up). Co= mpared to Stefan, I can achieve about 60% current into 60% effective antenn= a height, so my ERP should be ~ 9 dB weaker.
The two = carriers will be resolved by a 47 uHz spectrogram. But at lower resolution = (e.g. 424 uHz), they will merge into a two-hour sinusoidal beat pattern. Th= e idea is to use that to indirectly measure our phase difference, by observ= ing the times of maxima and minima at DL0AO in Amberg (and perhaps also in = Paul's spectrogram). As both carriers are GPS locked, the two transmitters = (or rather the two near-field pickup probe signals which are compared to GP= S) will be in phase at even hours (UT), and in antiphase at odd hours. Usin= g the known path difference (178 km =3D 4.9 lambda) to DL0AO, we could in p= rinciple calibrate the phase difference of our differently built phase-feed= back probes. This could then be used in the future to obtain 2 to 3 dB dire= ctional gain in any desired direction.

One shortcoming= of the measurement may be that while the 48 km path from myself to DL0AO i= s groundwave dominated, there will be a strong and variable skywave contrib= ution from DK7FC at 226 km. So any array steering calculated therefrom may = be incorrect during the daytime, or for long-distance paths with skywave fr= om both sources. It might however be possible to account for the diurnal ph= ase change using the DK7FC-DF6NM colour-phase measurement from Jan 28/29.

All the best,
Markus (DF6NM)

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