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 v9NJJcgZ016073 for ; Mon, 23 Oct 2017 21:19:41 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1e6i5Y-0005YX-Vx for rs_out_1@blacksheep.org; Mon, 23 Oct 2017 20:08:40 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1e6i5W-0005YO-FN for rsgb_lf_group@blacksheep.org; Mon, 23 Oct 2017 20:08:38 +0100 Received: from omr-a011e.mx.aol.com ([204.29.186.59]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.89) (envelope-from ) id 1e6i5S-0003cv-08 for rsgb_lf_group@blacksheep.org; Mon, 23 Oct 2017 20:08:37 +0100 Received: from mtaomg-aac02.mx.aol.com (mtaomg-aac02.mx.aol.com [172.27.2.36]) by omr-a011e.mx.aol.com (Outbound Mail Relay) with ESMTP id 66FE2380009C for ; Mon, 23 Oct 2017 15:08:31 -0400 (EDT) Received: from core-acd02e.mail.aol.com (core-acd02.mail.aol.com [172.27.22.12]) by mtaomg-aac02.mx.aol.com (OMAG/Core Interface) with ESMTP id 8C43238000085 for ; Mon, 23 Oct 2017 15:08:30 -0400 (EDT) Received: from 188.192.44.165 by webjas-vad102.srv.aolmail.net (10.96.35.105) with HTTP (WebMailUI); Mon, 23 Oct 2017 15:08:26 -0400 Date: Mon, 23 Oct 2017 15:08:30 -0400 From: Markus Vester To: rsgb_lf_group@blacksheep.org Message-Id: <15f4aa2d775-c09-1e2c7@webjas-vad102.srv.aolmail.net> In-Reply-To: <59EDCF40.3060603@posteo.de> MIME-Version: 1.0 X-MB-Message-Source: WebUI X-MB-Message-Type: User X-Mailer: JAS STD X-Originating-IP: [188.192.44.165] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20150623; t=1508785711; bh=5Y5CRNcnNt8n3efz/i2/1iNSB1g5XNgDTM9FpeIIjio=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=YoTjeGnn+0QgcEtuFNdI50X9V7vkhCOkWetInbnuzUN1dVLWQmk5Vhcv1P34Pe2h7 15GNFVGN+s6n1ZgmdXaxGKq8xH3A7aNwPsAAo+3ZooAA2FF34qcBCmkfmpYcEIH5X3 /zKauvVwz4CxeUfU9WscFhbEmqjAqmEU/z1hrVF0= x-aol-sid: 3039ac1b022459ee3e2e398c X-Spam-Score: 0.0 (/) 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 the administrator of that system for details. Content preview: Hi Stefan, VLF enthusiasts, in July 2015, I attempted a temporal correlation of "Tweek-mode" resonances in Heidelberg and Nürnberg against Blitzortung data from a passing storm front: http://df6nm.bplaced.net/VLF/spherics/tweek_resonances_dk7fc_df6nm_Blitzortung_150725_0700.jpg [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 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: 41a44ec7f64a884bcdc566aa8432178a Subject: Re: VLF: Using resonance effects of earth-ionosphere for radio experiments Content-Type: multipart/alternative; boundary="----=_Part_150405_744428372.1508785706869" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=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 ------=_Part_150405_744428372.1508785706869 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hi Stefan, VLF enthusiasts, in July 2015, I attempted a temporal correlation of "Tweek-mode" resonances= in Heidelberg and N=C3=BCrnberg against Blitzortung data from a passing st= orm front:=20 http://df6nm.bplaced.net/VLF/spherics/tweek_resonances_dk7fc_df6nm_Blitzort= ung_150725_0700.jpg It seems that the vertical resonances between earth and ionosphere extend o= nly to a lateral range of about 90 km, and they have died down at ~ 180 km.= Horizontal currents (e.g. cloud-to-cloud lightning or loop antennas with u= pward radiation) are required to excite and receive them. Respective emails with further details are at=20 https://uk.groups.yahoo.com/neo/groups/rsgb_lf_group/conversations/topics/4= 924 https://uk.groups.yahoo.com/neo/groups/rsgb_lf_group/conversations/messages= /4976 Best regards, Markus (DF6NM) =20 -----Urspr=C3=BCngliche Mitteilung-----=20 Von: DK7FC An: rsgb_lf_group Verschickt: Mo, 23. Okt 2017 13:17 Betreff: VLF: Using resonance effects of earth-ionosphere for radio experim= ents Paul, Markus, VLF, Some days ago there have been local thunderstorms near DL0AO in JN59.=20 Two images in attachemnt. The distance is about 225 km. The thunderstorms were on a small spot only. The sferics are clearly pronounced with an SNR increase of 10 dB and=20 more, quite a sharp peak/trace. That's not a new observation but now we=20 are operating just in that frequency range! The effect seems to appear in integer multiples of about 1.7 kHz, which=20 is roughly a wavelength of a 180 km, and the earth-ionosphere height is=20 just lambda/2. It would be most interesting to see how a similar spectrogram looks from=20 Pauls site (time and date given in the images). Is the effect still=20 there in 881 km? How strong is it expressed. Are the frequencies the same? If so, we should try to find that region of enhanced propagation, by=20 using a 2-tone or 3-tone carrier signal. No problem to provide that from=20 here. The effect is less expressed on 3.4 kHz in this event. Recently we=20 discussed about a geometric single-hop path difference between DK7FC and=20 DL0AO (Markus calculated 63.3 km difference between groundwave and=20 skywave). 5.17 is at a 1.09 lambda difference on that path, so=20 groundwave and skywave will add constructively. The 3rd order trace of=20 the sferic resonance effect is also at 5.1 kHz! 3.4 kHz, or the 88.2 km wave, is then at 1.4 lambda difference, so=20 skyway and groundwave do not add so constructive. Maybe this explains=20 the lower expressed resonance effect? It looks like there can be SNR difference of several dB when changing=20 the frequency by just a few 10 Hz, at least arround 5.1 kHz and on the=20 path to DL0AO. We should try to check that! Could there be a frequency with an advantage on the way to RN3AUS? On a=20 2000 km path the effects will be less expressed. But worth to think about..= . 73, Stefan ------=_Part_150405_744428372.1508785706869 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Hi Stefan, VLF enthusiasts,

in July = 2015, I attempted a temporal correlation of "Tweek-mode" resonances in= Heidelberg and N=C3=BCrnberg against Blitzortung data from a passing storm= front:
http://df6nm.bplaced.net/VLF/spherics/tweek_resonances_dk7fc_df= 6nm_Blitzortung_150725_0700.jpg

It seems that the vertical resonance= s between earth and ionosphere extend only to a lateral range of = about 90 km, and they have died down at ~ 180 km. Horizontal= currents (e.g. cloud-to-cloud lightning or loop antennas with upward = radiation) are required to excite and receive them.

Respective email= s with further details are at 
https://uk.groups.yahoo.com/neo/grou= ps/rsgb_lf_group/conversations/topics/4924
https://uk.groups.yahoo.com/n= eo/groups/rsgb_lf_group/conversations/messages/4976

Best regards,Markus (DF6NM)
 

-----Urspr=C3=BC= ngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo= .de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org&= gt;
Verschickt: Mo, 23. Okt 2017 13:17
Betr= eff: VLF: Using resonance effects of earth-ionosphere for radio experiments=

Paul, Markus, VLF,
=
Some days ago there have been local thunderstorms near DL0= AO in JN59.
Two images in attachemnt.
The = distance is about 225 km. The thunderstorms were on a small spot only.

The sferics are clearly pronounced with an SNR= increase of 10 dB and
more, quite a sharp peak/trace. Tha= t's not a new observation but now we
are operating just in= that frequency range!
The effect seems to appear in intege= r multiples of about 1.7 kHz, which
is roughly a wavelengt= h of a 180 km, and the earth-ionosphere height is
just lam= bda/2.

It would be most interesting to see= how a similar spectrogram looks from
Pauls site (time and= date given in the images). Is the effect still
there in 8= 81 km? How strong is it expressed. Are the frequencies the same?
If so, we should try to find that region of enhanced propagation, by =
using a 2-tone or 3-tone carrier signal. No problem to pro= vide that from
here.

The = effect is less expressed on 3.4 kHz in this event. Recently we
discussed about a geometric single-hop path difference between DK7FC a= nd
DL0AO (Markus calculated 63.3 km difference between gro= undwave and
skywave). 5.17 is at a 1.09 lambda difference = on that path, so
groundwave and skywave will add construct= ively. The 3rd order trace of
the sferic resonance effect = is also at 5.1 kHz!
3.4 kHz, or the 88.2 km wave, is then a= t 1.4 lambda difference, so
skyway and groundwave do not a= dd so constructive. Maybe this explains
the lower expresse= d resonance effect?

It looks like there ca= n be SNR difference of several dB when changing
the freque= ncy by just a few 10 Hz, at least arround 5.1 kHz and on the
path to DL0AO. We should try to check that!

Could there be a frequency with an advantage on the way to RN3AUS? On = a
2000 km path the effects will be less expressed. But wor= th to think about...

73, Stefan



------=_Part_150405_744428372.1508785706869--