Return-Path: Received: (qmail 98994 invoked from network); 1 Feb 2004 15:30:58 -0000 Received: from unknown (HELO ptb-mxscan03.plus.net) (212.159.14.237) by ptb-mailstore03.plus.net with SMTP; 1 Feb 2004 15:30:58 -0000 Received: (qmail 70566 invoked from network); 1 Feb 2004 15:30:57 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Priority: 3 X-MSMail-Priority: Normal X-Spam-detection-level: 11 Received: from ptb-mxcore03.plus.net (212.159.14.217) by ptb-mxscan03.plus.net with SMTP; 1 Feb 2004 15:30:56 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore03.plus.net with esmtp (Exim) id 1AnJYm-000IF2-PL for dave@picks.force9.co.uk; Sun, 01 Feb 2004 15:30:56 +0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1AnJXL-0003Ki-JQ for rs_out@blacksheep.org; Sun, 01 Feb 2004 15:29:27 +0000 Received: from [213.218.75.235] (helo=smtp06.freeler.nl) by post.thorcom.com with esmtp (Exim 4.14) id 1AnJXI-0003KZ-LB for rsgb_lf_group@blacksheep.org; Sun, 01 Feb 2004 15:29:24 +0000 Received: (qmail 28458 invoked from network); 1 Feb 2004 15:29:24 -0000 X-Fake-Domain: unknown Received: from unknown (HELO w8k3f0.freeler.nl) ([62.21.137.189]) (envelope-sender ) by smtp06.freeler.nl (qmail-ldap-1.03) with SMTP for ; 1 Feb 2004 15:29:23 -0000 Message-ID: <6.0.1.1.2.20040201150716.03705e90@POP3.freeler.nl> X-Sender: FRE0000086604@POP3.freeler.nl (Unverified) X-Mailer: QUALCOMM Windows Eudora Version 6.0.1.1 Date: Sun, 01 Feb 2004 15:13:35 +0100 To: "LF-Group" From: "Dick Rollema" MIME-Version: 1.0 Subject: LF: Fluctuating background noise Content-Type: text/html; charset=windows-1252 X-Spam-Checker-Version: SpamAssassin 2.60 (1.212-2003-09-23-exp) on post.thorcom.com X-Spam-Status: No, hits=0.0 required=5.0 tests=HTML_MESSAGE autolearn=no version=2.60 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: rs_out@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SPAMFiltered: yes X-Spam-Rating: 1 Content-transfer-encoding: 8bit To All from PA0SE,

When looking for VO1NA using SPECTRAN I noticed that at some moments the background noise more or less suddenly decreased and then Joe's signal became visible. The low noise leven was restricted to a narrow band of a few Hertz wide.
Has this been observed by others?
Because it occurred in such a narrow frequency band I think it may be caused by selective fading within the noise spectrum.  And if so may we conclude that the noise arrived via space wave?
Hw?

73, Dick, PA0SE