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 wAT9Fea3022402 for ; Thu, 29 Nov 2018 10:15:51 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1gSIDx-0007rz-R5 for rs_out_1@blacksheep.org; Thu, 29 Nov 2018 09:03:06 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1gSI8J-0007on-9Y for rsgb_lf_group@blacksheep.org; Thu, 29 Nov 2018 08:57:15 +0000 Received: from mout01.posteo.de ([185.67.36.65]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91_59-0488984) (envelope-from ) id 1gSI84-00014Y-IF for rsgb_lf_group@blacksheep.org; Thu, 29 Nov 2018 08:57:04 +0000 Received: from submission (posteo.de [89.146.220.130]) by mout01.posteo.de (Postfix) with ESMTPS id 53601160061 for ; Thu, 29 Nov 2018 09:56:58 +0100 (CET) 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=1543481818; bh=BJ0nXIUKHVy01qJBWPEB7ri03STECsCVAxICLtps25E=; h=Date:From:To:Subject:From; b=VCcn3MX/ZpATTEpYaW0lGoA4Pp+E6oXQpYzxbV/zswh0OX1Lsq/tr5jBlCdj8Ocyi aUyHsGT9dQAnYCefjo4qlpEzI2qusSv5rD2lMZc9f3VgpUrN6zzvKjZR07lzcUw6GP NEzoU+HAoB0TvcFzhoEHAt6J4Ft8a848Zb4nFEBw8A6EzKW0zJj+1Hpn9J9DSqTr6H BN4LA5jZTC+vUsKKMK2XmXZSnwIWNZKUvDV1phkU5TqcIZDMJtag2oAvJFVpYZmP3T ARhyigHlzRhZeZAPluz1ScYF8EvvEgzEw0eUbnEnwK5TAYnznhdGtSDzlHboeHBvM8 Zw6/oxV4Fj4yw== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 435BGd317Fz6tm9 for ; Thu, 29 Nov 2018 09:56:57 +0100 (CET) Message-ID: <5BFFA9D8.7070108@posteo.de> Date: Thu, 29 Nov 2018 09:56:56 +0100 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: LF: RE: EbNaut @ 80 Hz References: <5BE0C0CE.10008@posteo.de> <5BE19D5E.7000408@posteo.de> <5BF7C6B4.8090104@posteo.de> <5BFCFF7D.8090006@posteo.de> <041701d48769$2e6cb8e0$8b462aa0$@comcast.net> In-Reply-To: <041701d48769$2e6cb8e0$8b462aa0$@comcast.net> Content-Type: multipart/alternative; boundary="------------050600020005010707010707" X-Spam-Score: -2.3 (--) 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: Hello Jim, Thanks for the kind words. Well, the 60 Hz SNR is very weak here so the observations are limited. For me it looks like the 60 Hz trace is best visible in the morning, a few hours after my local sunset. Content analysis details: (-2.3 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [185.67.36.65 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_KAM_HTML_FONT_INVALID BODY: Test for Invalidly Named or Formatted Colors in HTML 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: ae3221d431bd19e5880aa98eda07ece4 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. --------------050600020005010707010707 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Hello Jim, Thanks for the kind words. Well, the 60 Hz SNR is very weak here so the observations are limited. For me it looks like the 60 Hz trace is best visible in the morning, a few hours after my local sunset. Both (all) spectrograms < 3 kHz are from the E field. The RDF spectrograms use the H field to define the colour only, see that explanation by DF6NM: http://df6nm.de/ColourDF/ColourDF.htm The mixing of the H fields is done in vlfrx-tools. This way the 3 channel stream becomes a 2 channel stream which is the fed to SpecLab. My loops are not sensitive in that range. Something to improve soon. Oh, did you actually see an unexpected SNR difference between the 3.8 mHz and the 424 uHz window?! This is very accurate observed. The reason is: The ZEVS window (3.8 mHz) uses a complex mixture of all 3 antennas, E, E-W,N-S to form a beam pointing towards ZEVS whereas the 424 uHz window simply shows the E field. But the H field components in the 3.8 mHz spectrogram are quite small, it is vtmix -c0.1/90,-0.25/-30,1/-20 The next step is to enter ELF of course. Yesterday i ordered some parts. The PA will be a special design, a HV cascade producing 40 kV DC. This DC voltage will be modulated with the ELF frequency. My plan is to try 23 Hz, the gap between the 3rd and 4th Schumann resonance, and later something lower than 10 Hz. So the DC voltage changes from 0 to 40 kV in a sine form. So the antenna will have a 20 kV DC component and a 40 kVpp AC component, i.e. abt 14 kV rms. This PA design works until including DC :-) It only works because the antenna current is sooo small and the ERP will be in the attowatt range. 73, Stefan Am 28.11.2018 23:24, schrieb hvanesce@comcast.net: > > Hello Stefan, > > Your SLF (270 Hz, 80 Hz and 60 Hz) experiments and observations have > been fascinating. It's been enjoyable to guess what your next result > would be; and encouraging to see that things at 270 Hz and 80 Hz seem > fairly well behaved so far. It was also interesting to notice on your > grabber that the 60Hz fading might not be diurnal. > > A question regarding your ZEVS and SLF spectrograms: > > Does your ZEVS spectrogram (79.8 Hz -- 83.2 Hz span) show lower SNR > for your 80 Hz signal than your SLF spectrogram (79.95 Hz -- 80.05 Hz > span) because one comes from an H-field sensor in the forest and the > other comes from an E-field sensor in the forest? The integration time > difference (3.8mHz vs 424 uHz?) would seem to account for 9.5 dB lower > SNR at 3.8 mHz, but the SNR in the ZEVS spectrogram (3.8 mHz) seems > lower by more than 10 dB, so I wondered if the two spectrograms came > from different antennas. > > 73, > > Jim AA5BW > > *From:* owner-rsgb_lf_group@blacksheep.org > [mailto:owner-rsgb_lf_group@blacksheep.org] *On Behalf Of *DK7FC > *Sent:* Tuesday, November 27, 2018 3:26 AM > *To:* rsgb_lf_group@blacksheep.org > *Subject:* SLF: EbNaut @ 80 Hz > > Hi SLF, > > Yesterday, a 45 character EbNaut was transmitted at 80.005 Hz. It was > received on my tree in 3.5 km distance. After the improvement of the > RX antenna it looks like i gained about 2.5 dB SNR. It was an easy > decode, the message could have been transmitted 4 times faster. > Capture attached :-) > > 73, Stefan > > PS: With that SNR, a 5 character message could be transferred out to 7 > km distance in less than 1 day. > > > > Am 23.11.2018 10:21, schrieb DK7FC: > > Dear SLF friends, > > A new step forward towards DC: Since yesterday 22:30 UTC i'm TXing a > carrier at *80.005 Hz*. That's the *3750 km band*, where the far field > begins at a distance of 598 km. > > The antenna voltage is just 5 kV and i'm getting 1.2 mA antenna > current, giving an *ERP of 20 fW* (2E-14 W). > > The voltage is even higher than in my recent experiment on 270 Hz, > anyway the S/N is lower, indicating that my RX lacks of sensitivity. > Indeed this experiment helps to estimate the lack of sensitivity. > Looks like i'm missing about 10 dB on that frequency. Anyway the > signal is making the path of 3.5 km to my tree grabber, as usual shown > at > http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html. > Not a big distance but still well beyond most garden fences! > The signal leaves a barely visible trace in the ZEVS window which is > running at 3.8 mHz FFT bin witdh. Unfortunately ZEVS is off the air > since a week or so. actually i wanted to transmit side by side with > ZEVS, of course a bit deeper even. > > From a quiet period at night, i calculated the SNR of a 1 hour carrier > period using vlfrx-tools: carrier *S/N: 16.83 dB in 277.8 uHz*, -18.73 > dB in 1Hz > > For the crazy homebrewers i'd like to share that website where i > ordered the HV-transformer, > http://www.hosin.de/Specials/HV-Trafo/hv-trafo.html A nightmare for > all safety-fetishists! For the completeness it must be mentioned > together with that page: http://kurts-werkstatt.de/hv-trafo.htm > > 73, Stefan > --------------050600020005010707010707 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hello Jim,

Thanks for the kind words.

Well, the 60 Hz SNR is very weak here so the observations are limited. For me it looks like the 60 Hz trace is best visible in the morning, a few hours after my local sunset.

Both (all) spectrograms < 3 kHz are from the E field. The RDF spectrograms use the H field to define the colour only, see that explanation by DF6NM: http://df6nm.de/ColourDF/ColourDF.htm The mixing of the H fields is done in vlfrx-tools. This way the 3 channel stream becomes a 2 channel stream which is the fed to SpecLab.

My loops are not sensitive in that range. Something to improve soon.

Oh, did you actually see an unexpected SNR difference between the 3.8 mHz and the 424 uHz window?! This is very accurate observed. The reason is: The ZEVS window (3.8 mHz) uses a complex mixture of all 3 antennas, E, E-W,N-S to form a beam pointing towards ZEVS whereas the 424 uHz window simply shows the E field. But the H field components in the 3.8 mHz spectrogram are quite small, it is vtmix -c0.1/90,-0.25/-30,1/-20

The next step is to enter ELF of course. Yesterday i ordered some parts. The PA will be a special design, a HV cascade producing 40 kV DC. This DC voltage will be modulated with the ELF frequency. My plan is to try 23 Hz, the gap between the 3rd and 4th Schumann resonance, and later something lower than 10 Hz. So the DC voltage changes from 0 to 40 kV in a sine form. So the antenna will have a 20 kV DC component and a 40 kVpp AC component, i.e. abt 14 kV rms. This PA design works until including DC :-) It only works because the antenna current is sooo small and the ERP will be in the attowatt range.

73, Stefan



Am 28.11.2018 23:24, schrieb hvanesce@comcast.net:

Hello Stefan,

 

Your SLF (270 Hz, 80 Hz and 60 Hz) experiments and observations have been fascinating. It’s been enjoyable to guess what your next result would be; and encouraging to see that things at 270 Hz and 80 Hz seem fairly well behaved so far. It was also interesting to notice on your grabber that the 60Hz fading might not be diurnal.  

 

A question regarding your ZEVS and SLF spectrograms:

Does your ZEVS spectrogram (79.8 Hz – 83.2 Hz span) show lower SNR for your 80 Hz signal than your SLF spectrogram (79.95 Hz – 80.05 Hz span) because one comes from an H-field sensor in the forest and the other comes from an E-field sensor in the forest? The integration time difference (3.8mHz vs 424 uHz?) would seem to account for 9.5 dB lower SNR at 3.8 mHz, but the SNR in the ZEVS spectrogram (3.8 mHz) seems lower by more than 10 dB, so I wondered if the two spectrograms came from different antennas.

 

73,

 

Jim AA5BW  

 

From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of DK7FC
Sent: Tuesday, November 27, 2018 3:26 AM
To: rsgb_lf_group@blacksheep.org
Subject: SLF: EbNaut @ 80 Hz

 

Hi SLF,

Yesterday, a 45 character EbNaut was transmitted at 80.005 Hz. It was received on my tree in 3.5 km distance. After the improvement of the RX antenna it looks like i gained about 2.5 dB SNR. It was an easy decode, the message could have been transmitted 4 times faster.
Capture attached :-)

73, Stefan

PS: With that SNR, a 5 character message could be transferred out to 7 km distance in less than 1 day.



Am 23.11.2018 10:21, schrieb DK7FC:

Dear SLF friends,

A new step forward towards DC: Since yesterday 22:30 UTC i'm TXing a carrier at 80.005 Hz. That's the 3750 km band, where the far field begins at a distance of 598 km.

The antenna voltage is just 5 kV and i'm getting 1.2 mA antenna current, giving an ERP of  20 fW (2E-14 W).

The voltage is even higher than in my recent experiment on 270 Hz, anyway the S/N is lower, indicating that my RX lacks of sensitivity. Indeed this experiment helps to estimate the lack of sensitivity. Looks like i'm missing about 10 dB on that frequency. Anyway the signal is making the path of 3.5 km to my tree grabber, as usual shown at http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html. Not a big distance but still well beyond most garden fences!
The signal leaves a barely visible trace in the ZEVS window which is running at 3.8 mHz FFT bin witdh. Unfortunately ZEVS is off the air since a week or so. actually i wanted to transmit side by side with ZEVS, of course a bit deeper even.

>From a quiet period at night, i calculated the SNR of a 1 hour carrier period using vlfrx-tools: carrier S/N: 16.83 dB in 277.8 uHz, -18.73 dB in 1Hz

For the crazy homebrewers i'd like to share that website where i ordered the HV-transformer, http://www.hosin.de/Specials/HV-Trafo/hv-trafo.html A nightmare for all safety-fetishists! For the completeness it must be mentioned together with that page: http://kurts-werkstatt.de/hv-trafo.htm

73, Stefan

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