Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mb04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 0EBFD3800010F; Fri, 3 May 2013 03:37:30 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1UYAXe-0007ex-HG for rs_out_1@blacksheep.org; Fri, 03 May 2013 08:36:30 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1UYAXe-0007eo-17 for rsgb_lf_group@blacksheep.org; Fri, 03 May 2013 08:36:30 +0100 Received: from omr-d04.mx.aol.com ([205.188.109.201]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1UYAXY-0002VU-Mb for rsgb_lf_group@blacksheep.org; Fri, 03 May 2013 08:36:28 +0100 Received: from mtaout-mb05.r1000.mx.aol.com (mtaout-mb05.r1000.mx.aol.com [172.29.41.69]) by omr-d04.mx.aol.com (Outbound Mail Relay) with ESMTP id 20FA0700000B7 for ; Fri, 3 May 2013 03:36:03 -0400 (EDT) Received: from White (188-195-246-26-dynip.superkabel.de [188.195.246.26]) by mtaout-mb05.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 86391E0000D0 for ; Fri, 3 May 2013 03:36:02 -0400 (EDT) Message-ID: <50100B1F0AB94D08B9E49C5DDB889EF3@White> From: "Markus Vester" To: References: <5182EB20.5000507@iup.uni-heidelberg.de> <73419E42F6C44E1EB1AB4FA0B2591817@SV8CSHP> Date: Fri, 3 May 2013 09:36:01 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 12.0.1606 X-MimeOLE: Produced By Microsoft MimeOLE V12.0.1606 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1367566563; bh=D4grFCxc2dvM85aoL8UqfMgclXWxB/tq+RDRZrGrX+o=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=VAl9Zt1Drqmvb5cLtZNverP/tmZZfGH7SJ+JdUz/yaKv1T2dospRMWTlpdv6KWupg QIUgUjRhamk2KzVKzZcmg/NNPKMNrDgCWUcLKmDSvswhHq936S8D7KK3t5lQUxbvL3 5BRirDg/+cJfmKRCTeHf0GmBTBwUqysqsYtoyTL8= X-AOL-SCOLL-SCORE: 0:2:295306656:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-Spam-Score: -2.6 (--) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Spiros, not really strange: the rising sun is suddenly ionizing lower ionospheric layers and increasing the absorption. Here's a somewhat simplistic explanation of diurnal propagation: At night, LF is mostly reflected by the lower boundary of the E-layer, at a height of about 100 km. After sunrise, radiations starts to penetrate deeper and ionize lower layers. So the conductivity of the D-layer increases so much that it starts first absorb and later reflect LF. [...] Content analysis details: (-2.6 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [205.188.109.201 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 SPF_PASS SPF: sender matches SPF record -2.6 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: b45446db24846e84db90eb694609e205 Subject: Re: LF: 136KHz propagation Content-Type: multipart/alternative; boundary="----=_NextPart_000_0040_01CE47E1.A0169010" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=HTML_30_40,HTML_MESSAGE, MISSING_OUTLOOK_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 x-aol-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mtain-mb04.r1000.mx.aol.com ; domain : mx.aol.com DKIM : pass x-aol-sid: 3039ac1d60185183693a419e X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_0040_01CE47E1.A0169010 Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable Hi Spiros, not really strange: the rising sun is suddenly ionizing lower = ionospheric layers and increasing the absorption.=20 Here's a somewhat simplistic explanation of diurnal propagation: At = night, LF is mostly reflected by the lower boundary of the E-layer, at a = height of about 100 km. After sunrise, radiations starts to penetrate = deeper and ionize lower layers. So the conductivity of the D-layer = increases so much that it starts first absorb and later reflect LF.=20 This is somewhat similar to a shunt resistor inserted in a transmission = line: During the night it's a large resistor which will let most of the = wave pass through, absorbing only a small fraction of the power which = depends on "conditions" (like DST index, describing charges leaking down = from a storage ring). At sunrise, the shunt suddenly conducts more = ("closer to 50 ohms") so most of the wave is being absorbed. At midday = when the sun is highest, the conductance is approaching a "short = circuit" which reflects the wave from a lower altitude (about 80 km). After sunset, the electrons and ions in the lower layers recombine = quickly so the D-layer becomes transparent again. However at high = altitudes, the gas density is so low that charges take long to find a = partner, thus ionisation of the E and F layers persists throughout the = night.=20 Best 73, Markus (DF6NM) From: SV8CS- Spiros Chimarios=20 Sent: Friday, May 03, 2013 5:58 AM To: rsgb_lf_group@blacksheep.org=20 Subject: LF: 136KHz propagation GM to all. The same strange propagation tonight as every night. At around 03.00z my signal disappear from DF6NM, DK7FC, YO/4X1RF & G4WGT = grabbers. I have better prop earlier and during the day with day light. 73, Spiros SV8CS ------=_NextPart_000_0040_01CE47E1.A0169010 Content-Type: text/html; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable
Hi Spiros,
 
not really = strange: the rising=20 sun is suddenly ionizing lower ionospheric layers and = increasing the=20 absorption. 
 
Here's a somewhat simplistic = explanation of diurnal=20 propagation: At night, LF is mostly reflected by the lower boundary of = the=20 E-layer, at a height of about 100 km. After sunrise, radiations starts = to=20 penetrate deeper and ionize lower layers. So the conductivity = of the=20 D-layer increases so much that it starts first absorb and = later reflect=20 LF. 
 
This is somewhat similar to a shunt=20 resistor inserted in a transmission line: During the = night it's=20 a large resistor which will let most of the wave pass through, = absorbing=20 only a small fraction of the power which depends on = "conditions" (like DST=20 index, describing charges leaking down from a storage ring). = At sunrise, the shunt = suddenly conducts=20 more ("closer to 50 ohms") so most of the wave is being absorbed. = At midday=20 when the sun is highest, the conductance is approaching a = "short=20 circuit" which reflects the wave from a lower altitude (about = 80=20 km).
 
After sunset, the electrons and ions in = the lower=20 layers recombine quickly so the D-layer becomes transparent again. = However at=20 high altitudes, the gas density is so low that charges = take long=20 to find a partner, thus ionisation of the E and F layers persists=20 throughout the night. 
 
Best = 73,
Markus = (DF6NM)

Sent: Friday, May 03, 2013 5:58 AM
Subject: LF: 136KHz propagation

GM to all.
The same strange propagation tonight as = every=20 night.
At around 03.00z my signal disappear from DF6NM, DK7FC, = YO/4X1RF &=20 G4WGT
grabbers.
I have better prop earlier and during the day = with day=20 light.
73, Spiros
SV8CS

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