Return-Path: Received: (qmail 29082 invoked from network); 15 Apr 2002 21:58:32 -0000 Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 15 Apr 2002 21:58:32 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 12208 invoked from network); 15 Apr 2002 21:58:29 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys.services.quay.plus.net with SMTP; 15 Apr 2002 21:58:29 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16xFuf-0002TM-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 16 Apr 2002 00:29:33 +0100 Received: from mta01.btfusion.com ([62.172.195.11] helo=btclick.com) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16xFue-0002TH-00 for rsgb_lf_group@blacksheep.org; Tue, 16 Apr 2002 00:29:32 +0100 Received: from virgin.net ([213.121.110.123]) by btclick.com (Netscape Messaging Server 4.15) with ESMTP id GUMQ0X02.P8B for ; Mon, 15 Apr 2002 22:50:57 +0100 Message-ID: <3CBB4AFD.30D47C43@virgin.net> Date: Mon, 15 Apr 2002 22:49:49 +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/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: I got out my copy of ISO/IEC 13818-1 which defines the transport system for digital televison. DTV systems have an accuracy defined by their 27 MHZ system clock. Everything is defined by that clock frame rate, line rate, colour burst. The accuracy is 27 000 000 +/- 810Hz with a permitted rate of change of <= 73 *10E-3 Hz/s Thus the phase measurements must be made wrt an analogue TV transmission. 73 Stewart G3YSX