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[195.171.43.25]) by mx.google.com with ESMTP id cb8si646530wib.78.2014.04.11.01.42.52 for ; Fri, 11 Apr 2014 01:42:52 -0700 (PDT) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org; dmarc=fail (p=NONE dis=NONE) header.from=me.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1WYVlZ-0006OO-B4 for rs_out_1@blacksheep.org; Fri, 11 Apr 2014 08:20:49 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1WYVlY-0006OF-Im for rsgb_lf_group@blacksheep.org; Fri, 11 Apr 2014 08:20:48 +0100 Received: from st11p06mm-asmtp001.mac.com ([17.172.124.249]) by relay1.thorcom.net with esmtp (Exim 4.82) (envelope-from ) id 1WYVlV-0008VQ-Im for rsgb_lf_group@blacksheep.org; Fri, 11 Apr 2014 08:20:47 +0100 MIME-version: 1.0 Received: from [192.168.0.100] (032-220-045-062.dynamic.caiway.nl [62.45.220.32]) by st11p06mm-asmtp001.mac.com (Oracle Communications Messaging Server 7u4-27.08(7.0.4.27.7) 64bit (built Aug 22 2013)) with ESMTPSA id <0N3U005JJV1PJZ30@st11p06mm-asmtp001.mac.com> for rsgb_lf_group@blacksheep.org; Fri, 11 Apr 2014 07:20:15 +0000 (GMT) References: <53388BDF.2090602@gmail.com> <5341AB93.5020407@gmail.com> From: Spring Global X-Mailer: iPad Mail (11D167) In-reply-to: Message-id: Date: Fri, 11 Apr 2014 09:20:17 +0200 To: "rsgb_lf_group@blacksheep.org" X-MANTSH: 1TEIXWV4bG1oaGkdHB0lGUkdDRl5PWBoaHhEKTEMXGx0EGx0YBBIZBBscEBseGh8 aEQpYTRdLEQptfhcaEQpMWRcbGhsbEQpZSRcRClleF2hjeREKQ04XSxsbGmJCH2lsHWN9GXhzB xloGh0YGmwSEQpYXBcZBBoEHQdNSx0SSEkcTAUbHQQbHRgEEhkEGxwQGx4aHxsRCl5ZF2FMflJ hEQpMRhdsa2sRCkNaFxwYBB4fBBgYGgQZGBEKRF4XGBEKQkUXbW9TAVxCGh19RHIRCkJOF2xwY HlAHWJSaRpiEQpCTBdhGGJhS0lsGExTXxEKQmwXa2hrR39GQlxaX3gRCkJAF25gaWFsGWFZH1l cEQpCWBdnQEcbTnx4UHlBGREKcGcXaV1+QFhtbkAabGcRCnBoF2MBTmdPfEdcZnhuEQpwaBdhe UBtZ2dyBWNCaBEKcGgXaFkbckxmZmYaW3MRCnBoF2docn1DcHwbG2VdEQpwaBducBpAfWljGU1 ASxEKcGcXYH5TbHp+aXhmWhoRCnBsF2VmUmhLHxNQbxxeEQ== X-CLX-Spam: false X-CLX-Score: 1011 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.11.96,1.0.14,0.0.0000 definitions=2014-04-11_03:2014-04-11,2014-04-11,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1402240000 definitions=main-1404110125 X-Spam-Score: -0.7 (/) 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: Could be a neighbour with plasma tv. I have the same with the plasma at home on many bands in hF Sent from my iPad > On 6 apr. 2014, at 21:57, John Rabson wrote: > > Stefan, > > On previous occasions when I have noticed side bands on your transmission, they have been at worst -40 dBc which is why I was puzzled about the -20. It did not make sense. You will note I did not originally suggest whose side bands they were as I was not able to identify the transmission. > > I have been doing some further checking here and the matter seems to be complicated by a lot of strong signals with 50 and 100 spacing across the band. Thank you for the suggestion about galvanic coupling. If the weather is fine tomorrow I will check the joints in the loop antenna I use for reception. > > 73, > John F5VLF > >> On 6 Apr 2014, at 21:31CEST, DK7FC <73dk7fc@googlemail.com> wrote: >> >> John, >> >> Last night i've checked my 50 Hz sidebands (actually 100 Hz) on LF by using SpecLab and a Tecsun PL660 receiver, both running on batteries (ferrite antenna) and coupled via a cable. >> The sidebands are at -40 dBc, see attachment. >> >> So maybe the problem is on your side. I remember a similar effect by MF WSPR decodes by a EA station. From that station i'm often getting 2 decodes in the same time slot, beeing 100 Hz distant and just 10 dB or so in SNR difference, which is also not caused on my side... >> Maybe a galvanic coupling with some mains harmonic currents on the antenna cable? >> >> 73, Stefan/DK7FC > [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [17.172.124.249 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record X-Scan-Signature: 0a4643e586472c13187d293ec5d096c2 Content-transfer-encoding: 7BIT Content-type: text/plain; CHARSET=US-ASCII Subject: Re: LF: Strong signal on 137 kHz X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=TO_ADDRESS_EQ_REAL 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 Could be a neighbour with plasma tv. I have the same with the plasma at home on many bands in hF Sent from my iPad > On 6 apr. 2014, at 21:57, John Rabson wrote: > > Stefan, > > On previous occasions when I have noticed side bands on your transmission, they have been at worst -40 dBc which is why I was puzzled about the -20. It did not make sense. You will note I did not originally suggest whose side bands they were as I was not able to identify the transmission. > > I have been doing some further checking here and the matter seems to be complicated by a lot of strong signals with 50 and 100 spacing across the band. Thank you for the suggestion about galvanic coupling. If the weather is fine tomorrow I will check the joints in the loop antenna I use for reception. > > 73, > John F5VLF > >> On 6 Apr 2014, at 21:31CEST, DK7FC <73dk7fc@googlemail.com> wrote: >> >> John, >> >> Last night i've checked my 50 Hz sidebands (actually 100 Hz) on LF by using SpecLab and a Tecsun PL660 receiver, both running on batteries (ferrite antenna) and coupled via a cable. >> The sidebands are at -40 dBc, see attachment. >> >> So maybe the problem is on your side. I remember a similar effect by MF WSPR decodes by a EA station. From that station i'm often getting 2 decodes in the same time slot, beeing 100 Hz distant and just 10 dB or so in SNR difference, which is also not caused on my side... >> Maybe a galvanic coupling with some mains harmonic currents on the antenna cable? >> >> 73, Stefan/DK7FC >