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 x4FCtVc4006124 for ; Wed, 15 May 2019 14:55:33 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1hQtNZ-0006IQ-6q for rs_out_1@blacksheep.org; Wed, 15 May 2019 13:51:29 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1hQtNW-0006IH-Su for rsgb_lf_group@blacksheep.org; Wed, 15 May 2019 13:51:26 +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 1hQtNV-0006RG-AW for rsgb_lf_group@blacksheep.org; Wed, 15 May 2019 13:51:25 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id C76012400FB for ; Wed, 15 May 2019 14:51:23 +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=1557924683; bh=22KjwBVci+22EDMb5YXd4LQNI3R0PsTHmfLk8fVBnaw=; h=Date:From:To:Subject:From; b=GzvivV/z9uDuOzg9riLVMhFQEdr8OF+NSai/EGRYEjcJ2sOSeTuM8hgTGy3Zu/Hll 0vJkytfvAo28Nfd/BvfIkjNQZkjnO2uzKTpH16QAhrOQNc71NZWpgO8DNtUq038sFN 7gJCEMGYwnF/j/1QjmUDLnqIHULOzExahEbbSJqdKfxHKSiJeXBt5tlY3+yCOLgjNk HAZDcmXI5YxN5Y92K1BsGcwJpfOGzdNqCYrPWn9LX/FMkFDdWGEt86LsWwCIfae/S3 uhSOrOCgI1QFIR2ueBbNzOWrl1gUcwpEkXNUYS1y67zS2I8rq2kd71tSaY2wA5j1Kj gs7uT6pY+f+ow== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 453vZ30LVMz9rxd for ; Wed, 15 May 2019 14:51:22 +0200 (CEST) Message-ID: <5CDC0B4A.2060803@posteo.de> Date: Wed, 15 May 2019 14:51:22 +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: <5CDB1096.5090309@posteo.de> <6DB8451D7F3D3947A5918808A59621EA3158A44F@servigilant.vigilant.local> In-Reply-To: <6DB8451D7F3D3947A5918808A59621EA3158A44F@servigilant.vigilant.local> 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: Hu Luis, Thanks. Yes i will. It does not even feel like a failure. Would have been fine for a 2 character EbNaut message, likely. But i keep trying to crack the 14 dB SNR level. 73, Stefan 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 T_KAM_HTML_FONT_INVALID BODY: Test for Invalidly Named or Formatted Colors in HTML 0.0 HTML_MESSAGE BODY: HTML included in message -0.1 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: caa2bbf6eb61e70e03599bec833fb637 Subject: Re: LF: RE: 2nd attempt at 270 Hz Content-Type: multipart/alternative; boundary="------------060907080505090305070400" 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. --------------060907080505090305070400 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Hu Luis, Thanks. Yes i will. It does not even feel like a failure. Would have been fine for a 2 character EbNaut message, likely. But i keep trying to crack the 14 dB SNR level. 73, Stefan Am 15.05.2019 14:34, schrieb VIGILANT Luis Fernández: > > Hi, SLF > > Amazing test Stefan! > > You have already surpassed all the limits in low bands. Just watching > here with mouth opened > > Keep paving the path to DC and thank you for sharing both, success and > failures. People has a tendency to hide failures ;-) > > 73 de Luis > > EA5DOM > > *De:* owner-rsgb_lf_group@blacksheep.org > [mailto:owner-rsgb_lf_group@blacksheep.org] *En nombre de *DK7FC > *Enviado el:* martes, 14 de mayo de 2019 21:02 > *Para:* rsgb_lf_group@blacksheep.org; Renato Romero > *Asunto:* SLF: 2nd attempt at 270 Hz > > Hello SLF freinds, > > Just a note from a recent experiment at *270.1 Hz.* > > On sunday morning, *2019-05-12_10:34,+150m*, i've done a carrier > transmission on my ground loop antenna again. I did not expect more > than, hopefully, a detectable spectrum peak in 57.6 km distance, i.e. > at my tree site. The tree receiver site was listening and recording > data using vlf-rx tools. > One E field antenna and two orthogonal loops were listening. The loops > have been improved recently! They consist out of a single circular > turn of 1.2 m diameter using 10mm diameter copper tube (about 25 > mm^2). It is a closed loop, non-resonated, with an impedance matching > transformer. This transformer previously had 1:100 turns. Now it > (they) has 2:240 turns, i.e. two turns primary (out of 14mm^2, AWG6). > This improved the sensitivity below 2 kHz significantly ( abt. 4...5 dB). > Furthermore the TX antenna length and angle has been improved, > resulting in about +3 dB more signal strength on the RX site! > > In a previous experiment at 270.1 Hz, some month ago, there was no > result at all, not the weakest trace, despite excessive tweaking of > all parameters. So the question was, will the improvements result in a > detectable signal now? > > Several things went wrong in that experiment. I forgot a bag > containing important equipment such as the power supply for the > netbook that generates the carrier signal. Also the output power was > not as high as planned, just about 380 W, giving *2.2 A antenna > current* (I measured 64.7 V at 1 A DC). Anyway i managed to improvise > so the experiment was started, but with some hours of delay which > meant i higher QRN background level. Then, on the WLAN link to the > tree, there were several interruptions of the stream (i'll move to 5 > GHz very soon!). I even got some QRM from my battery charger for some > short time periods (forgot to disable the charger remotely). So there > were several factors that could have been improved or avoided. And the > middle of May is not the ideal time anyway. > > Well, 270.1 Hz, that's the *1110 km band*! The far field begins at 177 > km distance, i.e. i am clearly in the near field here. Thus, from a > 'magnetic' TX antenna, we would expect that the signal is mainly > detectable on the H field, i.e. the loop antennas. > The first interesting results is that this expection is actually > confirmed. There is nothing detectable on the E field but the carrier > S/N in the H fields is close to 10 dB in the first run. Mixing the H > fields and tweaking the filters rises the* carrier S/N to 10.7 dB*, > see attachment. > > So far not really an undoubtly detection but it is a candidate for > optimism! With a few less problems during the experiment there is a > chance for 14 dB SNR. Also, there is quite much sideband QRM arround > 300 Hz which makes 270 Hz a bit harder to work on. > > 73, Stefan > --------------060907080505090305070400 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Hu Luis,

Thanks. Yes i will.
It does not even feel like a failure. Would have been fine for a 2 character EbNaut message, likely. But i keep trying to crack the 14 dB SNR level.

73, Stefan

Am 15.05.2019 14:34, schrieb VIGILANT Luis Fernández:

Hi, SLF

 

Amazing test Stefan!

 

You have already surpassed all the limits in low bands. Just watching here with mouth opened

Keep paving the path to DC and thank you for sharing both, success and failures. People has a tendency to hide failures ;-)

 

73 de Luis

EA5DOM

 

De: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] En nombre de DK7FC
Enviado el: martes, 14 de mayo de 2019 21:02
Para: rsgb_lf_group@blacksheep.org; Renato Romero <contact@vlf.it>
Asunto: SLF: 2nd attempt at 270 Hz

 

Hello SLF freinds,

Just a note from a recent experiment at 270.1 Hz.
 
On sunday morning, 2019-05-12_10:34,+150m, i've done a carrier transmission on my ground loop antenna again. I did not expect more than, hopefully, a detectable spectrum peak in 57.6 km distance, i.e. at my tree site. The tree receiver site was listening and recording data using vlf-rx tools.
One E field antenna and two orthogonal loops were listening. The loops have been improved recently! They consist out of a single circular turn of 1.2 m diameter using 10mm diameter copper tube (about 25 mm^2). It is a closed loop, non-resonated, with an impedance matching transformer. This transformer previously had 1:100 turns. Now it (they) has 2:240 turns, i.e. two turns primary (out of 14mm^2, AWG6). This improved the sensitivity below 2 kHz significantly ( abt. 4...5 dB).
Furthermore the TX antenna length and angle has been improved, resulting in about +3 dB more signal strength on the RX site!

In a previous experiment at 270.1 Hz, some month ago, there was no result at all, not the weakest trace, despite excessive tweaking of all parameters. So the question was, will the improvements result in a detectable signal now?

Several things went wrong in that experiment. I forgot a bag containing important equipment such as the power supply for the netbook that generates the carrier signal. Also the output power was not as high as planned, just about 380 W, giving 2.2 A antenna current (I measured 64.7 V at 1 A DC). Anyway i managed to improvise so the experiment was started, but with some hours of delay which meant i higher QRN background level. Then, on the WLAN link to the tree, there were several interruptions of the stream (i'll move to 5 GHz very soon!). I even got some QRM from my battery charger for some short time periods (forgot to disable the charger remotely). So there were several factors that could have been improved or avoided. And the middle of May is not the ideal time anyway.

Well, 270.1 Hz, that's the 1110 km band! The far field begins at 177 km distance, i.e. i am clearly in the near field here. Thus, from a 'magnetic' TX antenna, we would expect that the signal is mainly detectable on the H field, i.e. the loop antennas.
The first interesting results is that this expection is actually confirmed. There is nothing detectable on the E field but the carrier S/N in the H fields is close to 10 dB in the first run. Mixing the H fields and tweaking the filters rises the carrier S/N to 10.7 dB, see attachment.

So far not really an undoubtly detection but it is a candidate for optimism! With a few less problems during the experiment there is a chance for 14 dB SNR. Also, there is quite much sideband QRM arround 300 Hz which makes 270 Hz a bit harder to work on.

73, Stefan

--------------060907080505090305070400--