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 w76Ij5id029368 for ; Mon, 6 Aug 2018 20:45:06 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1fmkQQ-0007aM-IQ for rs_out_1@blacksheep.org; Mon, 06 Aug 2018 19:40:14 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1fmkQO-0007aD-9e for rsgb_lf_group@blacksheep.org; Mon, 06 Aug 2018 19:40:12 +0100 Received: from resqmta-ch2-10v.sys.comcast.net ([2001:558:fe21:29:69:252:207:42]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91_59-0488984) (envelope-from ) id 1fmkQM-0003bS-6N for rsgb_lf_group@blacksheep.org; Mon, 06 Aug 2018 19:40:11 +0100 Received: from resomta-ch2-20v.sys.comcast.net ([69.252.207.116]) by resqmta-ch2-10v.sys.comcast.net with ESMTP id mg54fBPiJpk4PmkQFfMmS9; Mon, 06 Aug 2018 18:40:03 +0000 X-DKIM-Result: Domain=comcast.net Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20161114; t=1533580803; bh=Y1oQSatlNmMIA0P+KE2oNqoKwHQHf63CI6ORvQx0t5A=; h=Received:Received:From:To:Subject:Date:Message-ID:MIME-Version: Content-Type; b=XhJZ8Hgz7mNC/RWPfBraWuQf6M3uS5SPZ9r+bLV7Rjmh4sNiWN0ebAo8wDhwe3V/z dNZulxt25RLdoqnrPfk19yTNrdNgnX6hXMbWXW2GyBrm/hs2VRKF0CYszkfKxy3Zdy npk/mhGfaiDH8LWyZq/H53NME90hWS9bMNgXaOb/c1arqH/MPaVEftTE2q3xu9L4i6 jo0WdZizF9mEqOlACU6x6+vmI7S64JnCV5eK6Ie4ovSwoA/Zy/5o6zLSZWw+hS2xVg bN6rLlEtLsKZEQhJ1LVeP7xAnPgFkX1to1qOEB+QqsFr5STGx2jMThTCq8kiXeTj+r GeOJWsushSOAg== Received: from Owner ([IPv6:2601:140:8500:7f9f:8d50:b44e:736a:7b41]) by resomta-ch2-20v.sys.comcast.net with ESMTPA id mkQCfCOSUTGiGmkQDf9r5X; Mon, 06 Aug 2018 18:40:02 +0000 From: To: References: <5B54CCCB.6060903@posteo.de> <5B59E687.5030805@posteo.de> <5B5C3ABF.3030809@posteo.de> <5B5C4A63.3040504@posteo.de> <5B5C5446.30105@posteo.de> <14080281532786049@iva8-6be7d23653d9.qloud-c.yandex.net> <5B5CD03F.40602@posteo.de> <14811811532865577@myt4-415a3339794b.qloud-c.yandex.net> <5B5DC8BC.9030601@posteo.de> <5B5E2D7D.6050908@posteo.de> <5B5F678B.7000506@posteo.de> <6dc15e3e-a325-4be2-55e3-44413e814f8a@web.de> <5B6050DA.60905@posteo.de> <5B60A72B.90103@posteo.de> <5B61E6FB.7090507@posteo.de> <072601d42a7a$66c4d7a0$344e86e0$@comcast.net> <5B645075.9090107@posteo.de> <5B6858EE.4000006@posteo.de> In-Reply-To: <5B6858EE.4000006@posteo.de> Date: Mon, 6 Aug 2018 14:40:00 -0400 Message-ID: <000a01d42db4$e28a88c0$a79f9a40$@comcast.net> MIME-Version: 1.0 X-Mailer: Microsoft Outlook 14.0 Thread-Index: AQGK+X/mQMWyuRdjsqX4eNmU0jy1AgH6HXhZAdBODi4BxZXZlgFXaCBDAcOIWOUBnYNBKQGxTZhLAYfRXfIBU2fEMwKcsQRKAKPPLBYCLTTnegIjmfQZAfApZLUBvUjkVQGZSzEBAo4oNHYDeOYMPqQ3x/mQ Content-Language: en-us X-CMAE-Envelope: MS4wfD0k7XxjmCPi5Z/3tscNnbbJQ1Yg34rmXwPkQIXus43cnFE2Div/kPCcP2qMcdkD1XC5F8jzxCBSDu+g8ra+aXVhKRk8Ea3+xkVvO5Q7giqGR2zkMCPJ GzaH1z5Nv7ewc5I27XnoOT68jRbniorFfW7HOUnYkcmnot0hyItaQ08mpHmZoGo/6kFjojpN7dRKB0nMmndcPR8PN8xXFpm325R2mT4dDll3z5GeZyuzmkSo qQ/nWUQStL/4bP8leJbYRg== X-Spam-Score: -0.7 (/) 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: Stefan, Congratulations on 2470 Hz and 1970 Hz (ULF) far-field records! A remarkable step from inverted-L efforts below 3 KHz last year; high SNR in 40 minutes at 2x far field on (if memory serves) the first attempt after your trial run. [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [2001:558:fe21:29:69:252:207:42 listed in] [list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (hvanesce[at]comcast.net) -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: 46fde0e85bb17687e691200506d0382f Subject: LF: RE: Experimenting on 2470 Hz and 1970 Hz Content-Type: multipart/alternative; boundary="----=_NextPart_000_000B_01D42D93.5B7B59C0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.1 required=5.0 tests=HTML_30_40,HTML_MESSAGE, NO_REAL_NAME 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 multipart message in MIME format. ------=_NextPart_000_000B_01D42D93.5B7B59C0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Stefan, =20 Congratulations on 2470 Hz and 1970 Hz (ULF) far-field records! =20 A remarkable step from inverted-L efforts below 3 KHz last year; high = SNR in 40 minutes at 2x far field on (if memory serves) the first = attempt after your trial run.=20 =20 Interesting that your 2470 Hz and 1970 Hz results were somewhat similar = in this variable-propagation region (2kHz-4kHz 100km-1000km). Could that = mean good things for lower frequencies? Perhaps most of your E-field is = vertically polarized with this loop; I wonder if that will provide more = stable propagation in this region. =20 Thanks for pushing the boundaries again. =20 73, =20 Jim AA5BW =20 =20 =20 =20 =20 From: owner-rsgb_lf_group@blacksheep.org = [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of DK7FC Sent: Monday, August 6, 2018 10:19 AM To: rsgb_lf_group@blacksheep.org Subject: ULF: Experimenting on 2470 Hz and 1970 Hz =20 Hi ULF,=20 On Sunday, 5th 2018 i successfully crossed the far field border on 2470 = Hz for the first time. That's the 121 km band. Later i even crossed it = on 1970 Hz, the 152 km band. These are two new records of the lowest = frequency signals generated by amateurs and received in the far field. = The distance between RX and TX was 55.6 km . The far field for 2470 Hz = starts at 19.4 km distance. For 1970 Hz it starts at 24.3 km distance. = The RX antenna and the TX antennas were loops! By running about 100 W (PA DC input) i managed to get 910 mA antenna = current on 2470 Hz into the earth loop in JN39WI. Here i transmitted a = plain carrier from 06:13...07:15 UTC.=20 Later i QSYed to 1970 Hz and here i got 910 mA as well. The 1970 Hz = transmission took place from 07:19...08:21 UTC. Despite beeing in the middle of a large forest there was good internet = connectivity and so i was able so watch my own grabber window showing = the band activity on 2470 Hz in a spectrogram of 424 uHz FFT bin width, = which is very wide for that frequency range! The spectrogram uses a Hann = window and the FFT window time is about 40 minutes, so it took some time = until a peak builts up. But already after 20 minutes i saw that = something happens! After 40 minutes the carrier transmission reached an = SNR of about 20 dB! It was a relatively quiet morning for early August. All the VLF stream data is stored into a ~ 12 day covering buffer so i = have the chance to optimise the filter settings and antenna mixing in a = postprocessing to achieve the best SNR from the system. For the 1970 Hz transmission there was no spectrogram available but = since i had internet access and a Linux notebook available, i processed = the VLF stream data (via SSH remote access to the storage PC) during the = transmission and followed the peak's SNR building up! It clearly looks like this antenna outperforms my large inverted L in 30 = m above the ground, at least into the ULF range! This opens up a new = room for experimentation on the way down to DC! :-) Now i need to get = rid of these output transformers since they will become problematic for = wide-band experimentation on ULF / SLF. Now, attached you can find two images showing spectrum peaks from the = two bands, out of the 55.6 km distance. The complete transmission time = is here integrated in one peak. Since the carrier S/N can also be = calculated from decoding a '*' message in EbNaut, i also show the = results for such calculation along with the whole postprocessing chain. Spectrograms will be produced as well, but this will take a few hours = here... 73, Stefan ------=_NextPart_000_000B_01D42D93.5B7B59C0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

Stefan,

 

Congratulations on 2470 Hz and 1970 Hz (ULF) far-field = records!

 

A remarkable step from inverted-L efforts below 3 KHz last year; high = SNR in 40 minutes at 2x far field on (if memory serves) the first = attempt after your trial run.

 

Interesting that your 2470 Hz and 1970 Hz results were somewhat = similar in this variable-propagation region (2kHz-4kHz 100km-1000km). = Could that mean good things for lower frequencies? Perhaps most of your = E-field is vertically polarized with this loop; I wonder if that will = provide more stable propagation in this region.

 

Thanks for pushing the boundaries again.

 

73,

 

Jim AA5BW

 

 

 

=C2=A0=C2=A0

 

From: owner-rsgb_lf_group@blacksheep.org = [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of = DK7FC
Sent: Monday, August 6, 2018 10:19 AM
To: = rsgb_lf_group@blacksheep.org
Subject: ULF: Experimenting on = 2470 Hz and 1970 Hz

 

Hi ULF, =

On Sunday, 5th 2018 i successfully crossed the far field border = on 2470 Hz for the first time. That's the 121 km band. = Later i even crossed it on 1970 Hz, the 152 km band. These = are two new records of the lowest frequency signals generated by = amateurs and received in the far field. The distance between RX and TX = was 55.6 km . The far field for 2470 Hz starts at 19.4 km distance. For = 1970 Hz it starts at 24.3 km distance. The RX antenna and the TX = antennas were loops!

By running about 100 W (PA DC input) i = managed to get 910 mA antenna current on 2470 Hz into the earth loop in = JN39WI. Here i transmitted a plain carrier from 06:13...07:15 UTC. =
Later i QSYed to 1970 Hz and here i got 910 mA as well. The 1970 Hz = transmission took place from 07:19...08:21 UTC.

Despite beeing in = the middle of a large forest there was good internet connectivity and so = i was able so watch my own grabber window showing the band activity on = 2470 Hz in a spectrogram of 424 uHz FFT bin width, which is very wide = for that frequency range! The spectrogram uses a Hann window and the FFT = window time is about 40 minutes, so it took some time until a peak = builts up. But already after 20 minutes i saw that something happens! = After 40 minutes the carrier transmission reached an SNR of about 20 dB! = It was a relatively quiet morning for early August.
All the VLF = stream data is stored into a ~ 12 day covering buffer so i have the = chance to optimise the filter settings and antenna mixing in a = postprocessing to achieve the best SNR from the system.

For the = 1970 Hz transmission there was no spectrogram available but since i had = internet access and a Linux notebook available, i processed the VLF = stream data (via SSH remote access to the storage PC) during the = transmission and followed the peak's SNR building up!

It clearly = looks like this antenna outperforms my large inverted L in 30 m above = the ground, at least into the ULF range! This opens up a new room for = experimentation on the way down to DC! :-) Now i need to get rid of = these output transformers since they will become problematic for = wide-band experimentation on ULF / SLF.

Now, attached you can = find two images showing spectrum peaks from the two bands, out of the = 55.6 km distance. The complete transmission time is here integrated in = one peak. Since the carrier S/N can also be calculated from decoding a = '*' message in EbNaut, i also show the results for such calculation = along with the whole postprocessing chain.

Spectrograms will be = produced as well, but this will take a few hours here...

73, = Stefan

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