Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id x5Q6UTus004643 for ; Wed, 26 Jun 2019 08:30:30 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1hg18a-0005bU-SH for rs_out_1@blacksheep.org; Wed, 26 Jun 2019 07:10:33 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1hg12L-0005b2-1K for rsgb_lf_group@blacksheep.org; Wed, 26 Jun 2019 07:04:05 +0100 Received: from mout02.posteo.de ([185.67.36.66]) by relay1.thorcom.net with esmtps (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92) (envelope-from ) id 1hg11z-0001AZ-G0 for rsgb_lf_group@blacksheep.org; Wed, 26 Jun 2019 07:03:44 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id 3773D2400E5 for ; Wed, 26 Jun 2019 08:03:41 +0200 (CEST) X-DKIM-Result: Domain=posteo.de Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.de; s=2017; t=1561529022; bh=xkuuq6GHo35v6JGUKzZzqNIZwSTiC5Wmjtgeq6xF9Hg=; h=Date:From:To:Subject:From; b=GX4DriHqECYq4s0uJAyTniunECa3UBZ13ICNitTXaGHCs2VUIFaL/WO6mc+zMj+Rk jrgnlbOhlPncPYsiUvvdZ/gR5/afw5lo/jYwDnqviHNiEt5G9pSC51xfKIvdLK1D3H kPf9YEWOmisnWNFbnraIoWbA/BfyzXKygboIMobTalaFf198SfiOYET0E9Qc/P9J/S fFi/uWJQKBclumHqSOOPH+earNjJqXw4N1kGMc6acHUuY1PDxZlgWysM4FUhj9OYUd BJdrkEO5B4aJtlJMine4bpgBbuVMRzlluNFLstL1nFCFRmhTEROkSsySrnh2MssbiT fdKHuM+OTSoRA== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 45YXXF2PYpz9rxL for ; Wed, 26 Jun 2019 08:03:41 +0200 (CEST) Message-ID: <5D130ABB.202@posteo.de> Date: Wed, 26 Jun 2019 08:03:39 +0200 From: DK7FC User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Subject: Re: ULF/VLF: amateur stair case / carrier transmissions References: <9ec649ed-7852-89b8-cb0e-d646de9538a9@rtv5.cz> <5D124169.1080309@posteo.de> <5D1268E1.9020500@posteo.de> <689441781.1158818.1561491108266@mail.yahoo.com> In-Reply-To: <689441781.1158818.1561491108266@mail.yahoo.com> Content-Type: multipart/alternative; boundary="------------090607060500040202070500" X-Spam-Score: -2.5 (--) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see @@CONTACT_ADDRESS@@ for details. Content preview: Hi Markus, Yes and it was a relatively quiet day. On my tree i got 27...30 dB SNR in 11 mHz on the higher frequencies, enough to calibrate the colours precisely. The coulours of the DL0AO grabber seem to be alig [...] Content analysis details: (-2.5 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [185.67.36.66 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.0 DKIMWL_WL_MED DKIMwl.org - Whitelisted Medium sender X-Scan-Signature: 8d5e679c4ecb21aeba32cebcefaae7cb X-SA-Exim-Scanned: No; SA Timed out after 180 secs 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 This is a multi-part message in MIME format. --------------090607060500040202070500 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi Markus, Yes and it was a relatively quiet day. On my tree i got 27...30 dB SNR in 11 mHz on the higher frequencies, enough to calibrate the colours precisely. The coulours of the DL0AO grabber seem to be aligned very well! My 'dot' in the 424 uHz spectrogram shows the correct direction. Did you apply a correction table for the colours there or is the phase response of the 3 antennas actually flat? With the new setup at DL0AO i bet we can soon detect something below 1970 Hz, which is so far the lowest frequency that was detected in > 1 lambda. 73, Stefan Am 25.06.2019 21:31, schrieb Markus Vester: > Hi Stefan, > > good work! You chose the best time of the day, producing nice > bright dots in the DL0AO 424 uHz spectrograms, estimated SNR up to 25 > dB SNR on 8270 and close to 30 dB on 5170 Hz. I'm curious what you > will derive from the recordings. > > Best 73, > Markus (DF6NM) > > > -----Ursprüngliche Mitteilung----- > Von: DK7FC > An: rsgb_lf_group > Verschickt: Di, 25. Jun. 2019 20:35 > Betreff: ULF/VLF: amateur stair case / carrier transmissions > > Hi all, > > Today, some 20 minute long carrier transmissions were drone from JN39WI > again. The main intention was to calibrate my local RDF spectrogram > (still to be done) in the range below 16.4 kHz (JXN) and above 82 Hz > (ZEVS). So that was a amateur radio ULF/VLF staircase somehow, despite > the weak signal strength relative to commercial transmitters. > > It was a hot day! Far > 30 C here. I started early in the morning and > enjoyed the fresh air in the forest. > > The DC resistance of the 1130m ground loop increased to 73.2 Ohm > (measured at 1 A) due to the dry soil. It confirms the dependency shown > in the last year! In 2018 i saw the resistance rising up to 94 Ohm in > late October, then it dropped to 57 Ohm (-40 %) in just 2 months. > > It was interesting to see that the antenna current is much higher at > lower frequencies (always at resonance | the PA output voltage is nearly > constant). This effect was very clearly expressed. > > IF of interest for other stations (having a data storage): > > Frequency/Hz Start time/UTC Antenna current/A > 970.005 2019-06-25_08:36:20,+20m 2.26 > 2970.005 2019-06-25_08:13:30,+20m 2.19 > 5170.005 2019-06-25_07:51:00,+20m 2.09 > 8270.005 2019-06-25_07:23:00,+25m 1.85 > end of the official part. > > > BTW, since a few days, the VLF RX site at DL0AO has a 3 axis VLF > receiver recording data from a Octo-soundcard and a Raspberry pi 3, > saving data to a 4 TB HDD so there is one more station that won't miss > anything from now on (for example unannounced transmissions by SAQ). > > Some spectrograms may be shown later. > > Evetually there was a problem with the sample rate correction due to the > upheating car, which caused a high deviation of the tracked sample rate. > The max allowed range of 10 ppm was left in the end of the experiment > but this was noticed a bit late, maybe. > > > 73, Stefan > > > --------------090607060500040202070500 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Markus,

Yes and it was a relatively quiet day. On my tree i got 27...30 dB SNR in 11 mHz on the higher frequencies, enough to calibrate the colours precisely.
The coulours of the DL0AO grabber seem to be aligned very well! My 'dot' in the 424 uHz spectrogram shows the correct direction. Did you apply a correction table for the colours there or is the phase response of the 3 antennas actually flat?

With the new setup at DL0AO i bet we can soon detect something below 1970 Hz, which is so far the lowest frequency that was detected in > 1 lambda.

73, Stefan

Am 25.06.2019 21:31, schrieb Markus Vester:
Hi Stefan,

good work! You chose the best time of the day, producing nice bright dots in the DL0AO 424 uHz spectrograms, estimated SNR up to 25 dB SNR on 8270 and close to 30 dB on 5170 Hz. I'm curious what you will derive from the recordings.

Best 73,
Markus (DF6NM)


-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Di, 25. Jun. 2019 20:35
Betreff: ULF/VLF: amateur stair case / carrier transmissions

Hi all,

Today, some 20 minute long carrier transmissions were drone from JN39WI
again. The main intention was to calibrate my local RDF spectrogram
(still to be done) in the range below 16.4 kHz (JXN) and above 82 Hz
(ZEVS). So that was a amateur radio ULF/VLF staircase somehow, despite
the weak signal strength relative to commercial transmitters.

It was a hot day! Far > 30 C here. I started early in the morning and
enjoyed the fresh air in the forest.

The DC resistance of the 1130m ground loop increased to 73.2 Ohm
(measured at 1 A) due to the dry soil. It confirms the dependency shown
in the last year! In 2018 i saw the resistance rising up to 94 Ohm in
late October, then it dropped to 57 Ohm (-40 %) in just 2 months.

It was interesting to see that the antenna current is much higher at
lower frequencies (always at resonance | the PA output voltage is nearly
constant). This effect was very clearly expressed.

IF of interest for other stations (having a data storage):

Frequency/Hz    Start time/UTC                        Antenna current/A
970.005            2019-06-25_08:36:20,+20m    2.26
2970.005          2019-06-25_08:13:30,+20m    2.19
5170.005          2019-06-25_07:51:00,+20m    2.09
8270.005          2019-06-25_07:23:00,+25m    1.85
end of the official part.


BTW, since a few days, the VLF RX site at DL0AO has a 3 axis VLF
receiver recording data from a Octo-soundcard and a Raspberry pi 3,
saving data to a 4 TB HDD so there is one more station that won't miss
anything from now on (for example unannounced transmissions by SAQ).

Some spectrograms may be shown later.

Evetually there was a problem with the sample rate correction due to the
upheating car, which caused a high deviation of the tracked sample rate.
The max allowed range of 10 ppm was left in the end of the experiment
but this was noticed a bit late, maybe.


73, Stefan



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