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 w917NdAM017318 for ; Mon, 1 Oct 2018 09:23:42 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1g6sTi-0007qy-Ne for rs_out_1@blacksheep.org; Mon, 01 Oct 2018 08:18:50 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1g6sTe-0007qp-LI for rsgb_lf_group@blacksheep.org; Mon, 01 Oct 2018 08:18:46 +0100 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 1g6sTb-0002fz-Tk for rsgb_lf_group@blacksheep.org; Mon, 01 Oct 2018 08:18:45 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout01.posteo.de (Postfix) with ESMTPS id 69AB320E35 for ; Mon, 1 Oct 2018 09:18:42 +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=1538378322; bh=KVz1VgCbGeccPW/1JOSgwHtUcqn0RdfCNc3qKFbOG7E=; h=Date:From:To:Subject:From; b=BL4mjBACiAAGDa9ijuT0IhB77T410FrQQAY78n/MQqLSN/6bFSbdAfQ2KZy4bOKzO tKpzBftBXWcYklxda21DPIQ5NX/TE6Mqi0V4Acne8NOZ96eSRh8Zo32Vj+8h48Op84 S9Yy9UKqtlS3xex3Q6cD7ZAxbdynqvho1KSLikVszfIu6ZcI+yOmcSgTNJA8TYZF/Y Rbibg+8NErpGesjXStPEgO/nh++3ycKwaz9qKq5GN5ksvrCr/AXItky/KTsk3i0P0C Hq5hjMlGcYhY01Q99r6Rxp1uO+OHZcE++FCmbg7cy+LMaq5fcF3pQn37nqiA+a8oJv E11B0g4bit9kw== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 42NttT4kgBz6tm8 for ; Mon, 1 Oct 2018 09:18:41 +0200 (CEST) Message-ID: <5BB1CA51.1030005@posteo.de> Date: Mon, 01 Oct 2018 09:18:41 +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: <00e801d457a0$f0c456d0$d24d0470$@comcast.net> <166244011c2-1ec5-3af1@webjasstg-vab11.srv.aolmail.net> <013301d4580b$080ef6f0$182ce4d0$@comcast.net> <5BAFE7D6.8050708@posteo.de> <019501d45915$822b5450$8681fcf0$@comcast.net> In-Reply-To: <019501d45915$822b5450$8681fcf0$@comcast.net> 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: Hi Jim, Thank you. Yes, it is still a bit hard to belive that i reached the far field in the 309 km band. What can be done on lower frequencies? Can i reach SLF on that distance and with this system(s)? It will be tested! [...] 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 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 T_KAM_HTML_FONT_INVALID BODY: Test for Invalidly Named or Formatted Colors in HTML 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 380fd5a215a6b3cdb950cc1613ae3360 Subject: Re: LF: RE: The next experiment on 970 Hz - Cracked the far field border below 1 kHz Content-Type: multipart/alternative; boundary="------------030904050803050101060709" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,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. --------------030904050803050101060709 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi Jim, Thank you. Yes, it is still a bit hard to belive that i reached the far field in the 309 km band. What can be done on lower frequencies? Can i reach SLF on that distance and with this system(s)? It will be tested! Meanwhile i got some better results for the carrier extraction: *vtread -T2018-09-29_08:05,+3h /raw | vtcat -p | vtmix -c-0.1,1,-0.2 | vtfilter -a th=7 -h lp,f=1500,poles=8 -h hp,f=400,poles=8 | vtblank -a29 -d0.0005 -t100 | vtmult -f970.01 | vtresample -r240 | vtresample -r1 | vtraw -oa | ebnaut -dp8K19A -r1 -c2 -v -f15 -f16 -M'***' -N3 -k20 -S24 carrier phase: 70.1 carrier Eb/N0: 2.5 dB carrier S/N: _14.82 dB in 93.0 uHz_, -25.50 dB in 1Hz, -59.48 dB in 2.5kHz* ...so now there is a small portion of the E-W loop and the E field antenna in the mix. But it makes only a difference of less than 0.2 dB. It would be good to have a radio amateur in adistance of 100 km or so but then he must have a really sensitive antenna and low QRM on that frequency/ frequency range. That is a problem. So i'm staying a lonely operator in that deep range :-) Today i want to try to send an EbNaut message over the distance. I'd better use a shorter message, just 3 characters instead of 5. More soon... 73, Stefan PS: In my last experiment, almost a year ago, i used the E field TX antenna. 12 kV antenna voltage resulted in about the same SNR, but when stacking 3 days. Now i need just 3 hours! Tells something about the performance of this loop... Am 01.10.2018 01:30, schrieb hvanesce@comcast.net: > > Stefan, > > Congratulations! A great milestone for many reasons. > > Amazing to think of far-field at that frequency without tons of > antenna; a credit to design, test planning, and test execution. > > Below 2 KHz is new territory for many reasons including markedly > different sky propagation and changing earth propagation which also > affects the character of noise*. > > Your (more than) year of considerable effort toward this goal probably > kept many on the edge of their seats, me included, I’m celebrating. > > In free space the electric field at a receiving antenna 0.18 > wavelengths away from a transmitting loop antenna should be very good > compared to the magnetic field at the same receiving location. > > But for a ground loop transmitting antenna at 970 Hz I wonder if > anyone knows which field (E or B) and which polarization (theta and > phi) predominates at a receiving antenna near the ground at 0.18 > wavelengths distance. A very interesting topic and perhaps your > E-field (monopole) and B field (loop) receiving antennas have provided > another milestone in this respect: perhaps a first documented data > point for E vs. B at any polarization, near 0.18 wavelengths (an > interesting distance on its own) from a ground-loop transmitting > antenna at 970 Hz? > > Another fascinating realm now opened, much appreciated. > > 73, > > Jim AA5BW > > *(noise characteristics including noise E strength vs. B strength vs. > noise polarization vs. distance from noise source vs noise-source-type > could be interesting at 970Hz) > > *From:* owner-rsgb_lf_group@blacksheep.org > [mailto:owner-rsgb_lf_group@blacksheep.org] *On Behalf Of *DK7FC > *Sent:* Saturday, September 29, 2018 5:00 PM > *To:* rsgb_lf_group@blacksheep.org > *Subject:* ULF: The next experiment on 970 Hz - Cracked the far field > border below 1 kHz > > Hi ULF, > > Today i run a carrier transmission on 970.01 Hz. Start time was 08:05 > UTC. The carrier run for 3 hours without an interruption. I got 1.9 A > antenna current on my ground loop antenna, about 320 W DC input to the PA. > The signal was received on my 3-axis RX on the tree in JN49IK. The > distance was, as usual, 55.6 km. > > So far the results were disappointing. I expected a strong SNR (at > least 10 dB in 424 uHz) from the new E field antenna which seems to > perform very well in the complete ULF range. However the analysis of a > two hour segment of the carrier showed an SNR of 6 dB, i.e. just > noise. However, as i routinely calculated the SNR from the N-S loop i > got a surprising SNR of 13.03 dB in 139.5 uHz. > At about 08:40 UTC the reception on the tree was disturbed by its own > solar charger, just for a few seconds but that was enough to create a > bright vertical line in the 424 uHz spectrogram showing the E field. > > Anyway, i just analysed the full 3 hour segment, only from the N-S > loop (which actually points rather to 30/210 deg) and got the > following result (including processing command line): > *vtread -T2018-09-29_08:05,+3h /raw | vtcat -p | vtmix -c0,1,0 | > vtfilter -a th=6 -h lp,f=1500,poles=8 | vtblank -a27 -d0.0005 -t100 | > vtmult -f970.01 | vtresample -r240 | vtresample -r1 | vtraw -oa | > ebnaut -dp8K19A -r1 -c2 -v -f15 -f16 -M'***' -N3 -k20 -S24 > carrier phase: -111.2 > carrier Eb/N0: 1.9 dB > carrier S/N: 14.25 dB in 93.0 uHz, -26.07 dB in 1Hz, -60.05 dB in 2.5kHz* > > This is the first far field detection of a 970 Hz signal generated by > amateurs on the 309 km band! A true milestone for me. Since more than > a year it was my goal to cross that far field border on that band. :-) > The efforts were immense. > The result is just preliminary. I want to tweak the parameters for a > higher SNR and try to filter out the short QRM from the charger. > > So now, why does the E field produce such bad results? At > http://www.iup.uni-heidelberg.de/schaefer_vlf/ULF/ULFSLFELF.png you > can see what it receives in the range of interest. The day/night QRN > difference is higher than on the loops, so the loops seemed to be > rather deaf. Does it maybe mean a steep reflexion on the ionosphere, > so that the E field antenna doesn't see it, but the loops do? > > Later i've done a DC measurement and got 1 A at 86.5 V, quite much > this time. Maybe a bad contact somewhere. Will check that. > > My 120 Ah LiFePo4 accu is fully recharged and i plan to do a new > experiment on monday morning, 3 hours before my solar charger starts > to work :-) The SNR seems to be promising, i plan to send a 5 > character EbNaut message. > > More results and a spectrum peak image will follow. > > 73, Stefan > --------------030904050803050101060709 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Jim,

Thank you.
Yes, it is still a bit hard to belive that i reached the far field in the 309 km band. What can be done on lower frequencies? Can i reach SLF on that distance and with this system(s)? It will be tested!

Meanwhile i got some better results for the carrier extraction:
vtread -T2018-09-29_08:05,+3h /raw | vtcat -p | vtmix -c-0.1,1,-0.2 | vtfilter -a th=7 -h lp,f=1500,poles=8 -h hp,f=400,poles=8 | vtblank -a29 -d0.0005 -t100 | vtmult -f970.01 | vtresample -r240 | vtresample -r1 | vtraw -oa | ebnaut -dp8K19A -r1 -c2 -v -f15 -f16 -M'***' -N3 -k20 -S24
carrier phase: 70.1
carrier Eb/N0: 2.5 dB
carrier S/N: 14.82 dB in 93.0 uHz, -25.50 dB in 1Hz, -59.48 dB in 2.5kHz

...so now there is a small portion of the E-W loop and the E field antenna in the mix. But it makes only a difference of less than 0.2 dB.

It would be good to have a radio amateur in adistance of 100 km or so but then he must have a really sensitive antenna and low QRM on that frequency/ frequency range. That is a problem. So i'm staying a lonely operator in that deep range :-)
Today i want to try to send an EbNaut message over the distance. I'd better use a shorter message, just 3 characters instead of 5.

More soon...

73, Stefan

PS: In my last experiment, almost a year ago, i used the E field TX antenna. 12 kV antenna voltage resulted in about the same SNR, but when stacking 3 days. Now i need just 3 hours! Tells something about the performance of this loop...




Am 01.10.2018 01:30, schrieb hvanesce@comcast.net:

Stefan,

 

Congratulations! A great milestone for many reasons.

 

Amazing to think of far-field at that frequency without tons of antenna; a credit to design, test planning, and test execution.

 

Below 2 KHz is new territory for many reasons including markedly different sky propagation and changing earth propagation which also affects the character of noise*.

 

Your (more than) year of considerable effort toward this goal probably kept many on the edge of their seats, me included, I’m celebrating.

 

In free space the electric field at a receiving antenna 0.18 wavelengths away from a transmitting loop antenna should be very good compared to the magnetic field at the same receiving location.

But for a ground loop transmitting antenna at 970 Hz I wonder if anyone knows which field (E or B) and which polarization (theta and phi) predominates at a receiving antenna near the ground at 0.18 wavelengths distance. A very interesting topic and perhaps your E-field (monopole) and B field (loop) receiving antennas have provided another milestone in this respect: perhaps a first documented data point for E vs. B at any polarization, near 0.18 wavelengths (an interesting distance on its own) from a ground-loop transmitting antenna at 970 Hz?

 

Another fascinating realm now opened, much appreciated.

73,

Jim AA5BW

 

 

*(noise characteristics including noise E strength vs. B strength vs. noise polarization vs. distance from noise source vs noise-source-type could be interesting at 970Hz)

 

 

 

 

From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of DK7FC
Sent: Saturday, September 29, 2018 5:00 PM
To: rsgb_lf_group@blacksheep.org
Subject: ULF: The next experiment on 970 Hz - Cracked the far field border below 1 kHz

 

Hi ULF,

Today i run a carrier transmission on 970.01 Hz. Start time was 08:05 UTC. The carrier run for 3 hours without an interruption. I got 1.9 A antenna current on my ground loop antenna, about 320 W DC input to the PA.
The signal was received on my 3-axis RX on the tree in JN49IK. The distance was, as usual, 55.6 km.

So far the results were disappointing. I expected a strong SNR (at least 10 dB in 424 uHz) from the new E field antenna which seems to perform very well in the complete ULF range. However the analysis of a two hour segment of the carrier showed an SNR of 6 dB, i.e. just noise. However, as i routinely calculated the SNR from the N-S loop i got a surprising SNR of 13.03 dB in 139.5 uHz.
At about 08:40 UTC the reception on the tree was disturbed by its own solar charger, just for a few seconds but that was enough to create a bright vertical line in the 424 uHz spectrogram showing the E field.

Anyway, i just analysed the full 3 hour segment, only from the N-S loop (which actually points rather to 30/210 deg) and got the following result (including processing command line):
vtread -T2018-09-29_08:05,+3h /raw | vtcat -p | vtmix -c0,1,0 | vtfilter -a th=6 -h lp,f=1500,poles=8 | vtblank -a27 -d0.0005 -t100 | vtmult -f970.01 | vtresample -r240 | vtresample -r1 | vtraw -oa | ebnaut -dp8K19A -r1 -c2 -v -f15 -f16 -M'***' -N3 -k20 -S24
carrier phase: -111.2
carrier Eb/N0: 1.9 dB
carrier S/N: 14.25 dB in 93.0 uHz, -26.07 dB in 1Hz, -60.05 dB in 2.5kHz

This is the first far field detection of a 970 Hz signal generated by amateurs on the 309 km band! A true milestone for me. Since more than a year it was my goal to cross that far field border on that band. :-) The efforts were immense.
The result is just preliminary. I want to tweak the parameters for a higher SNR and try to filter out the short QRM from the charger.

So now, why does the E field produce such bad results? At http://www.iup.uni-heidelberg.de/schaefer_vlf/ULF/ULFSLFELF.png you can see what it receives in the range of interest. The day/night QRN difference is higher than on the loops, so the loops seemed to be rather deaf. Does it maybe mean a steep reflexion on the ionosphere, so that the E field antenna doesn't see it, but the loops do?

Later i've done a DC measurement and got 1 A at 86.5 V, quite much this time. Maybe a bad contact somewhere. Will check that.

My 120 Ah LiFePo4 accu is fully recharged and i plan to do a new experiment on monday morning, 3 hours before my solar charger starts to work :-) The SNR seems to be promising, i plan to send a 5 character EbNaut message.

More results and a spectrum peak image will follow.

73, Stefan

--------------030904050803050101060709--