Return-Path: Received: (qmail 11000 invoked from network); 12 Feb 2001 02:18:38 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by extortion.plus.net with SMTP; 12 Feb 2001 02:18:38 -0000 Received: (qmail 19746 invoked from network); 12 Feb 2001 02:21:36 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 12 Feb 2001 02:21:36 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from majordom by post.thorcom.com with local (Exim 3.16 #1) id 14S8WT-0000of-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 12 Feb 2001 02:15:25 +0000 Received: from imo-d05.mx.aol.com ([205.188.157.37]) by post.thorcom.com with esmtp (Exim 3.16 #1) id 14S8WS-0000oW-00 for rsgb_lf_group@blacksheep.org; Mon, 12 Feb 2001 02:15:24 +0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from MarkusVester@aol.com by imo-d05.mx.aol.com (mail_out_v29.5.) id l.62.bd354dd (16336) for ; Sun, 11 Feb 2001 21:14:29 -0500 (EST) From: MarkusVester@aol.com Message-ID: <62.bd354dd.27b8a105@aol.com> Date: Sun, 11 Feb 2001 21:14:29 EST Subject: LF: Re:DCF39 frequency accuracy To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 8bit X-Mailer: AOL 4.0.i for Windows 95 sub 70 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Hi Peter and all, > I am using DCF39 to set the calibration of my rx and argo. There are two reasons why DBF39 may be of limited use for very precise frequency calibration: - Due to the phase-continuous FSK, the phase has shifted arbitrarily after each data burst. On Argo with 21mHz or finer resolution you will not see a narrow line but rather an irregular strip several ten mHz wide. - Even in the intervals between the telegrams, the freq appears to be slightly higher than nominal. Using a scope to directly measure the rate of phase advance relative to an OCXO reference derived from terrestrial TV "ZDF", I got 138830.030 Hz for DBF39 and 128930.014 Hz for DCF49, but these offsets may even be variable. On the other hand, 122.5 (DCF42 pilot), 153.0 (DLF radio) and of course 77.5 kHz (DCF77) seem to be very accurate. 73 and good luck Markus