Return-Path: X-Spam-DCC: paranoid 1102; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, SPF_PASS autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id u3HC5iG7029736 for ; Sun, 17 Apr 2016 14:05:44 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1arlOj-00071e-Rh for rs_out_1@blacksheep.org; Sun, 17 Apr 2016 13:01:53 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1arlOj-00071V-Jm for rsgb_lf_group@blacksheep.org; Sun, 17 Apr 2016 13:01:53 +0100 Received: from know-smtprelay-omc-9.server.virginmedia.net ([80.0.253.73]) by relay1.thorcom.net with esmtp (Exim 4.87) (envelope-from ) id 1arlOh-0005nx-VW for rsgb_lf_group@blacksheep.org; Sun, 17 Apr 2016 13:01:52 +0100 Received: from [192.168.1.6] ([86.31.33.210]) by know-smtprelay-9-imp with bizsmtp id jQ1o1s0064Y1DuW01Q1qq4; Sun, 17 Apr 2016 13:01:50 +0100 X-Originating-IP: [86.31.33.210] X-Spam: 0 X-Authority: v=2.1 cv=OPvapnuB c=1 sm=1 tr=0 a=jn/JOh/JfiX48zzdjRLp/g==:117 a=jn/JOh/JfiX48zzdjRLp/g==:17 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10 a=s5jvgZ67dGcA:10 a=kj9zAlcOel0A:10 a=dikU1YDVMsDZNk48ME4A:9 a=CjuIK1q_8ugA:10 From: "Mike Dennison" To: rsgb_lf_group@blacksheep.org, rsgb_lf_group@yahoogroups.co.uk Date: Sun, 17 Apr 2016 13:01:45 +0100 MIME-Version: 1.0 Message-ID: <57137B29.30466.5D54DFE@mike.dennison.ntlworld.com> X-mailer: Pegasus Mail for Windows (4.71.565) Content-description: Mail message body X-Scan-Signature: e09cca6d8e44a91eadbdfb3e1b8aec09 Subject: LF: 137kHz rarity Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.11 Status: O X-Status: X-Keywords: X-UID: 7758 There was some unusual propagation last night on 137kHz. Opera32 transmissions from IZ7SLZ were received well by M0DSZ or several hours but were not receive at all by me. Nothing strange there as M0DSZ has an exceptionally good receiver. I received R7NT's Op32 several times during the night whilst M0DSZ received him less often. Again, nothing odd as LF propagation is often selective. The really interesting thing was R7NT's SNR was around -40B with most reporting stations around Europe, and with me most of the time. But at 0007 he was -19dB, and at 0207 -17dB. Between these peaks, at 2312, 0112 and 0312UTC he was back to around -40. These were all genuine transmissions reported by several Eu stations every time, but no-one reported those big peaks which were more than 20dB above the Op32 reception limit. Big propagation enhanced peaks are commonplace on the HF-SHF bands but rare on 137kHz. It seems they are also geographically very selective. Mike, G3XDV ==========