Return-Path: Received: (qmail 3195 invoked from network); 13 Apr 2003 20:11:21 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 13 Apr 2003 20:11:21 -0000 Received: (qmail 21746 invoked from network); 13 Apr 2003 20:11:09 -0000 Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 13 Apr 2003 20:11:09 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.14) id 194noH-0003Di-UN for rsgb_lf_group-outgoing@blacksheep.org; Sun, 13 Apr 2003 21:10:41 +0100 Received: from [194.73.73.93] (helo=rhenium.btinternet.com) by post.thorcom.com with esmtp (Exim 4.14) id 194noD-0003DZ-6w for rsgb_lf_group@blacksheep.org; Sun, 13 Apr 2003 21:10:37 +0100 Received: from host213-122-203-99.in-addr.btopenworld.com ([213.122.203.99] helo=Main) by rhenium.btinternet.com with smtp (Exim 3.22 #23) id 194noC-0007WR-00 for rsgb_lf_group@blacksheep.org; Sun, 13 Apr 2003 21:10:36 +0100 Message-ID: <000701c301f8$9f293160$6507a8c0@Main> From: "Alan Melia" To: "LF-Group" Date: Sun, 13 Apr 2003 21:09:08 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: Propagation Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=0.0 required=5.0tests=noneversion=2.51 X-Spam-Checker-Version: SpamAssassin 2.51 (1.174.2.5-2003-03-20-exp) X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rsgb_lf_group-outgoing@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false Hi all, We may be in for some improvements in night-time propagation now. We have just had 3 straight days with the Geomagnetic Index, Kp<4, and the NOAA SEC site forecasts quiet conditions for the outlook period. This would just about bring us to the situation that, I believe, would give reasonable, if not particularly spectacular, levels on the Trans-Atlantic path. My feeling is that we need 7 to 10 days of quiet conditions during which conditions will improve. This means that next weekend could be a fair window to try before the summer noise conditions wipe out reception on the band. The best guide will be to watch the site run by Steve Dove W3EEE http://www.w3eee.com and click on the DCF39 Live tab on the left-hand side. This will show a plot of the German utility station DCF39 for the last 24 hours. Good condition are long periods above -20dB peak levels are at around -7dB for the best nights seen this year. One week ago the yellow trace of DCF39 was within 1dB of the blue "noise" trace, but the levels have been creeping up over the last few days. Note though that the darkness path has shortened considerably since January. The first rise in level is now not appearing until well after 2400z and dawn in Europe determines the collapse of conditions. It is accurate enough to consider the ground level dawn as the end of the night because the emerging sunlight hits the ionosphere about 1000 to 1500 kms west of the ground level dawn. It is this point that you require to return your signal for a two hop path. The emerging sunlight lowers the "reflection level" and thumps in about 20dB of attenuation, known as D-layer absorption. Happy Hunting Cheers de Alan G3NYK alan.melia@btinternet.com