Return-Path: X-Spam-DCC: paranoid 1481; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_MESSAGE,RATWARE_GECKO_BUILD,SPF_PASS autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id u8IEMxSt028019 for ; Sun, 18 Sep 2016 16:22:59 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1blcwI-0002mm-Lx for rs_out_1@blacksheep.org; Sun, 18 Sep 2016 15:19:26 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1blcwI-0002md-6D for rsgb_lf_group@blacksheep.org; Sun, 18 Sep 2016 15:19:26 +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 4.87) (envelope-from ) id 1blcwE-0008RV-Iz for rsgb_lf_group@blacksheep.org; Sun, 18 Sep 2016 15:19:25 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id 62AE020A47 for ; Sun, 18 Sep 2016 16:19:20 +0200 (CEST) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3scWNl44wpz100b; Sun, 18 Sep 2016 16:19:19 +0200 (CEST) Message-ID: <57DEA267.5040100@posteo.de> Date: Sun, 18 Sep 2016 16:19:19 +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, Renato Romero References: <556C6A05176D4D3C9703327B948B9A53@PCPMF> <8BD4D5505807414E8895F6B90A91FCCE@AGB> <57D56BB8.2050304@posteo.de> In-Reply-To: <57D56BB8.2050304@posteo.de> X-Scan-Signature: eec106d36eb876515d296e51093c048c Subject: ULF: New distance record (?) on the 101 km band: 31.3 km Content-Type: multipart/alternative; boundary="------------080805000309060403000609" 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 2.56 on 10.1.3.11 Status: RO X-Status: A X-Keywords: X-UID: 8783 This is a multi-part message in MIME format. --------------080805000309060403000609 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Hi ULF, Now the results of the post-processing of my 3 day recording are available. It shows very clearly that my 250 nW ERP (average 46 mA antenna current), 2970 Hz signal was copied in *31.3 km* distance. The recording location was in a more or less quiet location, in http://no.nonsense.ee/qth/map.html?qth=JN49IQ37AM. The transmission path is shown in *http://no.nonsense.ee/qth/map.html?qth=JN49IQ37AM&from=jn49ik00wd* In this second attempt, everything worked fine, stable GPS reception, accurate orientation of the vertical, single turn receive loop and the recording of a single 30 GB .raw file at 32 kS/s (covering 0...16 kHz). However the QRN could have been lower. But there was no QRM by electrical fences... Here's a spectrogram showing the complete, unfiltered recording: *https://dl.dropboxusercontent.com/u/19882028/ULF/31km_wide_3days.jpg * Of course there is nothing visible of the transmission in this resolution, it is just an overview to get an impression about QRN and QRM in that location. QRM from trains and mains harmonics is the critical parameter on ULF. The transmission consists of 3 parts: A long dash on 2970.000 Hz, then the message "73" in DFCW-12000 (2.5 mHz frequency shift) with the lower dash sent on 2970.000 Hz and then another long dash on 2969.990 Hz After filtering and noise blanking, here are the resulting spectrograms in 476 uHz and 238 uHz: *https://dl.dropboxusercontent.com/u/19882028/ULF/31km_476uHz.jpg* *https://dl.dropboxusercontent.com/u/19882028/ULF/31km_238uHz.jpg* The experienced visual human spectrogram interpreter experts may find a significant part of the message :-) Just as a reference, here are spectrograms showing the same transmission received in 3.5 km distance (http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html). https://dl.dropboxusercontent.com/u/19882028/ULF/ref_424uHz.jpg https://dl.dropboxusercontent.com/u/19882028/ULF/ref_212uHz.jpg I'm not sure if this is the highest distance ever crossed with a message by radio amateurs on ULF (0.3...3 kHz), but it is certainly one of them :-) A new experiment in about 65 km distance is in preparation. Probably it will be done in a few weeks. The location will be quieter (the Pfälzer Wald, JN39VH) and there will be less QRN! 73, Stefan/DK7FC Am 11.09.2016 16:35, schrieb DK7FC: > Hi ULF, > > Since yesterday (10.Sep), 11 UTC, i'm running a new experiment on the > 101 km band. It is in 31.2 km distance to my transmitter-site. > > The last experiment did not produce satisfying results due to various > reasons. > > Now i improved the loop cross section area, the loop orientation, GPS > reception (for the 1 PPS + NMEA reference signal). Furthermore the > recording sample rate was reduced to 32 kS/s which allows about 3 days > of stereo recording. > I'm still using the Raspberry Pi2 for therecording. The system > consumes just 150 mA from a 12V battery. 3x 7 Ah lead acid batteries > are in use now. > > The transmission contains stable carriers and a short DFCW-12000 > message, "73". The transmission can be followed on my 3.5 km distant > forest grabber at > http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html > , as usual. > > Relative to the last experiment, the average QRN has dropped > significantly now, another advantage. So i'm quite optimistic to get a > good result! > > The next experiment in about 60 km distance is already in preparation. > Then i will use my new coil which is still in preparation. The last > measurement, after completing the 3rd stack, showed a resonance > frequency of 4.27 kHz. So it should have 2.8 H now... > In the next experiment, i will use 100 mA antenna current, again a > about 6 dB stronger signal. > > The current experiment will stop on Tuesday afternoon. Results can be > expected in the end of the next week. > > 73, Stefan/DK7FC > > > --------------080805000309060403000609 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hi ULF,

Now the results of the post-processing of my 3 day recording are available. It shows very clearly that my 250 nW ERP (average 46 mA antenna current), 2970 Hz signal was copied in 31.3 km distance. The recording location was in a more or less quiet location, in http://no.nonsense.ee/qth/map.html?qth=JN49IQ37AM. The transmission path is shown in http://no.nonsense.ee/qth/map.html?qth=JN49IQ37AM&from=jn49ik00wd

In this second attempt, everything worked fine, stable GPS reception, accurate orientation of the vertical, single turn receive loop and the recording of a single 30 GB .raw file at 32 kS/s (covering 0...16 kHz). However the QRN could have been lower. But there was no QRM by electrical fences...

Here's a spectrogram showing the complete, unfiltered recording: https://dl.dropboxusercontent.com/u/19882028/ULF/31km_wide_3days.jpg
Of course there is nothing visible of the transmission in this resolution, it is just an overview to get an impression about QRN and QRM in that location. QRM from trains and mains harmonics is the critical parameter on ULF.

The transmission consists of 3 parts: A long dash on 2970.000 Hz, then the message "73" in DFCW-12000 (2.5 mHz frequency shift) with the lower dash sent on 2970.000 Hz and then another long dash on 2969.990 Hz

After filtering and noise blanking, here are the resulting spectrograms in 476 uHz and 238 uHz:
https://dl.dropboxusercontent.com/u/19882028/ULF/31km_476uHz.jpg
https://dl.dropboxusercontent.com/u/19882028/ULF/31km_238uHz.jpg

The experienced visual human spectrogram interpreter experts may find a significant part of the message :-)

Just as a reference, here are spectrograms showing the same transmission received in 3.5 km distance (http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html).
https://dl.dropboxusercontent.com/u/19882028/ULF/ref_424uHz.jpg
https://dl.dropboxusercontent.com/u/19882028/ULF/ref_212uHz.jpg

I'm not sure if this is the highest distance ever crossed with a message by radio amateurs on ULF (0.3...3 kHz), but it is certainly one of them :-)

A new experiment in about 65 km distance is in preparation. Probably it will be done in a few weeks. The location will be quieter (the Pfälzer Wald, JN39VH) and there will be less QRN!

73, Stefan/DK7FC



Am 11.09.2016 16:35, schrieb DK7FC:
Hi ULF,

Since yesterday (10.Sep), 11 UTC, i'm running a new experiment on the 101 km band. It is in 31.2 km distance to my transmitter-site.

The last experiment did not produce satisfying results due to various reasons.

Now i improved the loop cross section area, the loop orientation, GPS reception (for the 1 PPS + NMEA reference signal). Furthermore the recording sample rate was reduced to 32 kS/s which allows about 3 days of stereo recording.
I'm still using the Raspberry Pi2 for therecording. The system consumes just 150 mA from a 12V battery. 3x 7 Ah lead acid batteries are in use now.

The transmission contains stable carriers and a short DFCW-12000 message, "73". The transmission can be followed on my 3.5 km distant forest grabber at http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html , as usual.

Relative to the last experiment, the average QRN has dropped significantly now, another advantage. So i'm quite optimistic to get a good result!

The next experiment in about 60 km distance is already in preparation. Then i will use my new coil which is still in preparation. The last measurement, after completing the 3rd stack, showed a resonance frequency of 4.27 kHz. So it should have 2.8 H now...
In the next experiment, i will use 100 mA antenna current, again a about 6 dB stronger signal.

The current experiment will stop on Tuesday afternoon. Results can be expected in the end of the next week.

73, Stefan/DK7FC



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