Return-Path: Received: (qmail 94616 invoked from network); 13 Apr 2004 20:53:20 -0000 Received: from unknown (HELO ptb-mxscan03.plus.net) (212.159.14.237) by ptb-mailstore02.plus.net with SMTP; 13 Apr 2004 20:53:20 -0000 Received: (qmail 43451 invoked from network); 13 Apr 2004 20:53:19 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from ptb-mxcore03.plus.net (212.159.14.217) by ptb-mxscan03.plus.net with SMTP; 13 Apr 2004 20:53:12 -0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore03.plus.net with esmtp (Exim) id 1BDUu8-000ADe-5p for dave@picks.force9.co.uk; Tue, 13 Apr 2004 21:53:12 +0100 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1BDUtN-0006lA-B3 for rs_out_1@blacksheep.org; Tue, 13 Apr 2004 21:52:25 +0100 Received: from [213.232.95.59] (helo=relay.salmark.net) by post.thorcom.com with esmtp (Exim 4.14) id 1BDUtM-0006l1-Ms for rsgb_lf_group@blacksheep.org; Tue, 13 Apr 2004 21:52:24 +0100 Received: from imo-d06.mx.aol.com ([205.188.157.38]) by relay.salmark.net with esmtp (Exim 4.24) id 1BDUtB-0007li-RO for rsgb_lf_group@blacksheep.org; Tue, 13 Apr 2004 21:52:13 +0100 X-Fake-Domain: MarkusVester@aol.com Received: from MarkusVester@aol.com by imo-d06.mx.aol.com (mail_out_v37_r1.2.) id l.163.2e253918 (17526) for ; Tue, 13 Apr 2004 16:51:29 -0400 (EDT) From: MarkusVester@aol.com Message-ID: <163.2e253918.2dadacd1@aol.com> Date: Tue, 13 Apr 2004 16:51:29 EDT To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 X-Mailer: 8.0 for Windows sub 6104 X-Spam-Score: 0.7 (/) X-Spam-Report: HTML_MESSAGE=0.001,HTML_TAG_BALANCE_HTML=0.411,NO_REAL_NAME=0.285 Subject: Re: LF: CT<>ZL Content-Type: text/html; charset=windows-1252 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Status: No, hits=0.7 required=5.0 tests=HTML_MESSAGE, HTML_TAG_BALANCE_HTML,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 X-PN-SPAMFiltered: yes X-Spam-Rating: 1 Content-transfer-encoding: 8bit Dear LF group,

late again, but nevertheless - congratulations to Ed's group, Sam, Mike and Bob on their fantastic LF DX results!

Marek and Brian,
- on the other hand, there might be some sort of focussing gain on an antipode path. There was an interesting paper on ELF propagation (ie. 76 and 82Hz) by P. Bannister and A. Fraser-Smith, showing a formula and a couple of measured data points confirming that:
http://www-star.stanford.edu/~acfs/82Hz.pdf

Of course the situation may be very different for our "short" LF waves, which would be less likely to stay in coherence over such distances. But then again, observing the NCDXF beacon network on 14100 kHz a few years ago, I found much more consistent reception of ZL6B around the day, compared to closer ones like VK6 and KH6 which were rather erratic.

73 de Markus, DF6NM

In einer eMail vom 13.04.2004 19:45:38 Westeuropäische Normalzeit schreibt brian@esoterica.pt:

If a significant dark path is necessary as it would appear from the recently reported captures of DCF39 in New Zealand, I postulate that it is not possible under "normal" conditions to achieve longwave communication over the ~20,000km. However all is not lost as previous experience with 160m showed that sporadic but very infrequent communication was possible over this path and at signal strengths that need some explaining.

Perhaps someone with better understanding of this phenomenon (and better maths than mine) could calculate the diameter of the effective "cone of silence" around diametrically situated stations and suggest a strategy to exploit whatever phenomenon assisted communication on 160m.

Please discuss.