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 v8PMMLWr013459 for ; Tue, 26 Sep 2017 00:22:22 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1dwbVi-0002HR-7J for rs_out_1@blacksheep.org; Mon, 25 Sep 2017 23:05:54 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1dwbVg-0002HI-Tt for rsgb_lf_group@blacksheep.org; Mon, 25 Sep 2017 23:05:52 +0100 Received: from mout02.posteo.de ([185.67.36.66]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1dwbVb-0006jj-Aw for rsgb_lf_group@blacksheep.org; Mon, 25 Sep 2017 23:05:51 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id C242B20E94 for ; Tue, 26 Sep 2017 00:05:43 +0200 (CEST) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3y1J7C0hLpzyrG for ; Tue, 26 Sep 2017 00:05:43 +0200 (CEST) Message-ID: <59C97DB6.3070102@posteo.de> Date: Tue, 26 Sep 2017 00:05:42 +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 References: <15eb990d1e5-c02-28ac5@webjas-vaa005.srv.aolmail.net> In-Reply-To: <15eb990d1e5-c02-28ac5@webjas-vaa005.srv.aolmail.net> X-Spam-Score: 0.0 (/) 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 the administrator of that system for details. Content preview: Hi Markus, Am 25.09.2017 17:03, schrieb Markus Vester: > Have you also tried to look for Schumann resonances in the recording? I tried but saw nothing. So either the signal level from the loop is to small (i think so) and/or the frequency response of the preamp also contributes. > > Instead of the 84 turns, you could probably employ a single turn loop > with a transformer. So perhaps your antenna in the tree might receive > ELF as well? You know, on the tree i'm using a single turn loop and a ferrite transformer with 100 turns secondary. But the preamp was designed for a low power consumption. The LT1028 must run from the 12 V level, 5 V is not enough. VLF was a rather low priority during the time i built the preamp. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: 81978068c3ed22c636bd574cc661f8bd Subject: Re: ELF: ZEVS reception from a small loop Content-Type: multipart/alternative; boundary="------------090103000107090707080601" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,HTML_MESSAGE 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 This is a multi-part message in MIME format. --------------090103000107090707080601 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi Markus, Am 25.09.2017 17:03, schrieb Markus Vester: > Have you also tried to look for Schumann resonances in the recording? I tried but saw nothing. So either the signal level from the loop is to small (i think so) and/or the frequency response of the preamp also contributes. > > Instead of the 84 turns, you could probably employ a single turn loop > with a transformer. So perhaps your antenna in the tree might receive > ELF as well? You know, on the tree i'm using a single turn loop and a ferrite transformer with 100 turns secondary. But the preamp was designed for a low power consumption. The LT1028 must run from the 12 V level, 5 V is not enough. VLF was a rather low priority during the time i built the preamp. BUT: You may have noticed some interruptions on the grabber yesterday. This happend because i set up a new firmware on the Raspi (now Linux 8 / Jessie). vlfrx tools is also installed already. I want to observe if the new system is running stable, then i consider to install one of the octo soundcards there. And then i could run 2 channels for MF and 3 channels for VLF and 1 channel for PPS. If i do so, i would need a new preamp anyway. And then i can watch the E field from there too. But that will take time... 73, Stefan > > Best 73, > Markus > > -----Ursprüngliche Mitteilung----- > Von: DK7FC > An: rsgb_lf_group > Cc: Renato Romero > Verschickt: Mo, 25. Sept 2017 15:18 > Betreff: ELF: ZEVS reception from a small loop > > Hi LF friends, > > You know, a few weeka ago i've been in France. We had a field day and > i tested my small loop with its new preamp. Description below. > From a handy loop with just 0.8 m diameter and 84 turns i didn't > expect much. However i saw my 4470.005 Hz carrier quite well even in > 424 uHz FFT bandwidth which is not bad at all for 250 km distance. It > even was a noisy day. > > But now: I reprocessed the recording (which was done by the Raspi and > vlfrx tools) again, looking for ZEVS on 82 Hz. > To my surprise ZEVS has a very good SNR from that small antenna! It > was up to 25 dB in 3.8 mHz! That's the celarest signal i saw from > ZEVS, so far. For the spectrogram i used a 1.5 kHz low pass filter and > a noise blanker. > See: > http://www.iup.uni-heidelberg.de/schaefer_vlf/VLF/ZEVS__from_JN29PD06BO.png > > So my loop setup seems to be promising for the next 970 Hz experiment > as well :-) > > 73, Stefan > > PS: The preamp design is taken from: > http://www.vlf.it/feletti2/idealloop.html > > > Am 18.09.2017 00:56, schrieb DK7FC: > > > Am 31.08.2017 22:37, schrieb DK7FC: > > This weekend i will be in France again, JN29OD96SK > , on a > field day with the radio club. I plan to receive the 4470 Hz > signal with a small loop and its new preamp and the octo > soundcard. Thus i want to run a carrier again on 4470.005 Hz. > Tomorrow, Friday, i will transmit the EbNaut message again. > After that, the carrier will continue until sunday. With some > luck i hope you can decode the message when including the > friday transmission. If not, i could continue to transmit on > monday... > > > It took some time but now i have some results from that > experiment. I actually placed a 84 turn loop with 0.8 m diameter > and a low noise preamp between some trees in France, JN29PD06BO. > A path of 250 km or 3.7 wavelengths between RX and TX ( > http://no.nonsense.ee/qth/map.html?qth=JN29PD06BO&from=jn49ik00wd > ). > Quite a compact RX system for VLF. I did not prepare the > experiment as good as possible, there was no E field RX together > with the loop. H field only. It was mainly another test of the > octo-soundcard and a first test for the samll loop and its LNA. > I converted the data files recorded by vlfrx tools into a wav file > and analysed it in SpecLab. Here is a wideband spectrogram showing > the QRN: > http://www.iup.uni-heidelberg.de/schaefer_vlf/VLF/wide4470.png > (time markers are incorrect there) > > On sunday morning, 3rd Spetember when i looked at the installation > i found that the preamp was disconnected from the battery. It must > have been an animal walking arround into the field, stumbling over > the cable ;-) . Fortunately the interruption took just about one > hour ;-) > Assuming that vlfrx tools correctly resampled to 24 kS/s i run the > file into SpecLab set to 47 uHz FFT bin width, hoping to see a > trace/peak at 4470.005 Hz. > And indeed, there is something! See attachment. That's a first > trace from DL to F on the 67 km band :-) About 18 dB in 47 uHz > during the best time, much more than i expected. > > Another success is that i managed to produce a first spectrum peak > and generated a png file using vlfrx tools. The procedure is based > on Paul's advice. :-) > > 73, Stefan > > > > > > > > > > --------------090103000107090707080601 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Markus,

Am 25.09.2017 17:03, schrieb Markus Vester:
Have you also tried to look for Schumann resonances in the recording?
I tried but saw nothing. So either the signal level from the loop is to small (i think so) and/or the frequency response of the preamp also contributes.

Instead of the 84 turns, you could probably employ a single turn loop with a transformer. So perhaps your antenna in the tree might receive ELF as well?
You know, on the tree i'm using a single turn loop and a ferrite transformer with 100 turns secondary. But the preamp was designed for a low power consumption. The LT1028 must run from the 12 V level, 5 V is not enough. VLF was a rather low priority during the time i built the preamp.

BUT: You may have noticed some interruptions on the grabber yesterday. This happend because i set up a new firmware on the Raspi (now Linux 8 / Jessie). vlfrx tools is also installed already. I want to observe if the new system is running stable, then i consider to install one of the octo soundcards there. And then i could run 2 channels for MF and 3 channels for VLF and 1 channel for PPS. If i do so, i would need a new preamp anyway. And then i can watch the E field from there too. But that will take time...

73, Stefan


Best 73,
Markus

-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Cc: Renato Romero <contact@vlf.it>
Verschickt: Mo, 25. Sept 2017 15:18
Betreff: ELF: ZEVS reception from a small loop

Hi LF friends,

You know, a few weeka ago i've been in France. We had a field day and i tested my small loop with its new preamp. Description below.
>From a handy loop with just 0.8 m diameter and 84 turns i didn't expect much. However i saw my 4470.005 Hz carrier quite well even in 424 uHz FFT bandwidth which is not bad at all for 250 km distance. It even was a noisy day.

But now: I reprocessed the recording (which was done by the Raspi and vlfrx tools) again, looking for ZEVS on 82 Hz.
To my surprise ZEVS has a very good SNR from that small antenna! It was up to 25 dB in 3.8 mHz! That's the celarest signal i saw from ZEVS, so far. For the spectrogram i used a 1.5 kHz low pass filter and a noise blanker.
See: http://www.iup.uni-heidelberg.de/schaefer_vlf/VLF/ZEVS__from_JN29PD06BO.png

So my loop setup seems to be promising for the next 970 Hz experiment as well :-)

73, Stefan

PS: The preamp design is taken from: http://www.vlf.it/feletti2/idealloop.html


Am 18.09.2017 00:56, schrieb DK7FC:

Am 31.08.2017 22:37, schrieb DK7FC:
This weekend i will be in France again, JN29OD96SK , on a field day with the radio club. I plan to receive the 4470 Hz signal with a small loop and its new preamp and the octo soundcard. Thus i want to run a carrier again on 4470.005 Hz. Tomorrow, Friday, i will transmit the EbNaut message again. After that, the carrier will continue until sunday. With some luck i hope you can decode the message when including the friday transmission. If not, i could continue to transmit on monday...

It took some time but now i have some results from that experiment. I actually placed a 84 turn loop with 0.8 m diameter and a low noise preamp between some trees in France, JN29PD06BO.
A path of 250 km or 3.7 wavelengths between RX and TX ( http://no.nonsense.ee/qth/map.html?qth=JN29PD06BO&from=jn49ik00wd ). Quite a compact RX system for VLF. I did not prepare the experiment as good as possible, there was no E field RX together with the loop. H field only. It was mainly another test of the octo-soundcard and a first test for the samll loop and its LNA.
I converted the data files recorded by vlfrx tools into a wav file and analysed it in SpecLab. Here is a wideband spectrogram showing the QRN: http://www.iup.uni-heidelberg.de/schaefer_vlf/VLF/wide4470.png (time markers are incorrect there)

On sunday morning, 3rd Spetember when i looked at the installation i found that the preamp was disconnected from the battery. It must have been an animal walking arround into the field, stumbling over the cable ;-) . Fortunately the interruption took just about one hour ;-)
Assuming that vlfrx tools correctly resampled to 24 kS/s i run the file into SpecLab set to 47 uHz FFT bin width, hoping to see a trace/peak at 4470.005 Hz.
And indeed, there is something! See attachment. That's a first trace from DL to F on the 67 km band :-) About 18 dB in 47 uHz during the best time, much more than i expected.

Another success is that i managed to produce a first spectrum peak and generated a png file using vlfrx tools. The procedure is based on Paul's advice. :-)

73, Stefan










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