Return-Path: Received: (qmail 22706 invoked from network); 13 Apr 2002 09:03:59 -0000 Received: from unknown (HELO warrior.services.quay.plus.net) (212.159.14.227) by excalibur-qfe1-smtp-plusnet.harl.plus.net with SMTP; 13 Apr 2002 09:03:59 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 19222 invoked from network); 13 Apr 2002 09:04:00 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior.services.quay.plus.net with SMTP; 13 Apr 2002 09:04:00 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16wKvP-0003VT-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 13 Apr 2002 11:38:31 +0100 Received: from mta01.btfusion.com ([62.172.195.11] helo=btclick.com) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16wKvO-0003VN-00 for rsgb_lf_group@blacksheep.org; Sat, 13 Apr 2002 11:38:30 +0100 Received: from virgin.net ([213.121.110.123]) by btclick.com (Netscape Messaging Server 4.15) with ESMTP id GUI0ZW05.FUI for ; Sat, 13 Apr 2002 09:59:56 +0100 Message-ID: <3CB7F349.154325B4@virgin.net> Date: Sat, 13 Apr 2002 09:58:49 +0100 From: "Stewart Bryant" X-Mailer: Mozilla 4.76 [en]C-CCK-MCD (Windows NT 5.0; U) X-Accept-Language: en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Subject: Re: LF: Phase meter for propagation experiment References: Content-Type: text/html; charset=windows-1252 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Content-transfer-encoding: 8bit Wolf

The sharp phase transition may well be a broadcasting centre handover.
Using TV frame reference is a neat idea, because in order to stop
the most destructive type of co-channel interference the broadcasters
have to run them at exactly the same frequency line frequency. However I
do not see why they would worry about phase transitions on a occasional
basis.

73

Stewart G3YSX

DL4YHF@aol.com wrote:

Hello group,

I made two phase plots of 1.5 hours length yesterday, the first with MSF (60kHz), the second with DCF77 (77.5kHz).
To calibrate sample rate and the receiver's LO, the 15625 Hz TV sync ("ZDF") and its harmonics at 62.5 kHz (for the MSF plot) and 78125 (for the DCF plot) were used.

The graphs are attached.
"Ampl1" (red) is the amplitude of the TV sync,
"Phase1" (green) its phase which shows that the software is not perfect,
"Ampl2" (blue) is the amplitude of the MSF- or DCF carrier,
"Phase2" (purple) shows the variation of the MSF- or DCF phase. The absolute value is meaningless, it depends on when the measurement started.

It appears that the long-term phase stability of the ZDF TV sync against MSF and DCF is very good. The phase graph shows some "ups and downs", the maximum phase deviation is 50° over the 1.5 hour observation period.
I expected a significantly lower phase variation in the DCF graph. The reason is still unknown, maybe the 'calibration' algorithm needs more tweaking.

Regards,
 Wolf