Return-Path: Received: from rly-df07.mx.aol.com (rly-df07.mail.aol.com [172.19.156.20]) by air-df01.mail.aol.com (v123.3) with ESMTP id MAILINDF011-56349aeef2d28f; Wed, 04 Mar 2009 16:14:28 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-df07.mx.aol.com (v123.3) with ESMTP id MAILRELAYINDF074-56349aeef2d28f; Wed, 04 Mar 2009 16:14:23 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1LeyPZ-0001TT-6M for rs_out_1@blacksheep.org; Wed, 04 Mar 2009 21:13:53 +0000 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1LeyPY-0001TK-Oh for rsgb_lf_group@blacksheep.org; Wed, 04 Mar 2009 21:13:52 +0000 Received: from imo-d06.mx.aol.com ([205.188.157.38]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1LeyPX-0000Rn-Sz for rsgb_lf_group@blacksheep.org; Wed, 04 Mar 2009 21:13:52 +0000 Received: from MarkusVester@aol.com by imo-d06.mx.aol.com (mail_out_v39.1.) id l.bdb.3e30feeb (34967) for ; Wed, 4 Mar 2009 16:13:18 -0500 (EST) Received: from Black (g229115213.adsl.alicedsl.de [92.229.115.213]) by cia-da07.mx.aol.com (v123.3) with ESMTP id MAILCIADA074-889749aeeeec1ba; Wed, 04 Mar 2009 16:13:17 -0500 Message-ID: <04DB809048FC434FBA0D4DB387E89863@Black> From: "Markus Vester" To: References: <8FA0F64CAE294E9681BFE4D22D1EB2D4@ns94d01ae4d850> In-Reply-To: <8FA0F64CAE294E9681BFE4D22D1EB2D4@ns94d01ae4d850> Date: Wed, 4 Mar 2009 22:13:14 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6000.16480 X-MIMEOLE: Produced By Microsoft MimeOLE V6.0.6000.16669 X-Spam-Flag:NO X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: Re: capture 67hz.jpg Content-Type: multipart/alternative; boundary="----=_NextPart_000_000C_01C99D16.696ECC00" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.3 required=5.0 tests=HTML_50_60,HTML_MESSAGE, MISSING_OUTLOOK_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-AOL-IP: 193.82.116.20 ------=_NextPart_000_000C_01C99D16.696ECC00 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear Henny, my QTH is about 400 m from a railway line, and I regularly saw their 16.667=20= Hz power frequency and several ELF harmonics. The E-fields are relatively st= rong as the lines normally do not carry a grounded top wire for lightning pr= otection. The "modulation" could be caused by some switching activity. Another origin might be a controlled rectifier on the 50 Hz mains, which cou= ld be triggered at a subharmonic frequency. Best regards, Markus, DF6NM ----- Original Message -----=20 From: henny van elst=20 To: blacksheep=20 Sent: Wednesday, March 04, 2009 7:43 PM Subject: LF: capture 67hz.jpg Hi,Lf capture unid signal 67hz,but who ? henny pa3cpm best 73s ------=_NextPart_000_000C_01C99D16.696ECC00 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Dear Henny,
 
my QTH is about 400 m from a railway l= ine,=20 and I regularly saw their 16.667 Hz power frequency and several EL= F=20 harmonics. The E-fields are relatively strong as the lines normally do not c= arry=20 a grounded top wire for lightni= ng=20 protection. The "modulation" could be caused by some switching=20 activity.
 
Another origin might be a=20 controlled rectifier on the 50 Hz mains, which could be triggered=20 at a subharmonic frequency.
 
Best regards,
Markus, DF6NM
 
----- Original Message -----
henny van elst=20=
To: blacksheep
Sent: Wednesday, March 04, 2009 7:4= 3=20 PM
Subject: LF: capture 67hz.jpg

Hi,Lf
capture unid signal 67hz,but who ?=
henny pa3cpm
best 73s
= ------=_NextPart_000_000C_01C99D16.696ECC00--