Return-Path: Received: (qmail 11827 invoked from network); 28 Apr 2001 09:57:01 -0000 Received: from unknown (HELO warrior-inbound.servers.plus.net) (212.159.14.227) by excalibur.plus.net with SMTP; 28 Apr 2001 09:57:01 -0000 Received: (qmail 16865 invoked from network); 28 Apr 2001 09:56:36 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior with SMTP; 28 Apr 2001 09:56:36 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 14tRDY-0001Al-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 28 Apr 2001 10:40:44 +0100 Received: from gadolinium.btinternet.com ([194.73.73.111]) by post.thorcom.com with esmtp (Exim 3.16 #2) id 14tRDX-0001Ag-00 for rsgb_lf_group@blacksheep.org; Sat, 28 Apr 2001 10:40:43 +0100 Received: from [213.122.59.79] (helo=default) by gadolinium.btinternet.com with smtp (Exim 3.03 #83) id 14tRD3-00022X-00 for rsgb_lf_group@blacksheep.org; Sat, 28 Apr 2001 10:40:14 +0100 Message-ID: <000001c0cfcf$fe8b5d20$4f3b7ad5@default> From: "Fred Rattray" To: rsgb_lf_group@blacksheep.org References: <3.0.1.16.20010427101015.085fece4@mail.cc.kuleuven.ac.be> <3AE9C14B.73BB9A48@usa.net> Subject: LF: Re: Re: DFCW an idea. Date: Sat, 28 Apr 2001 10:24:14 -0000 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Could you not use a standard time source such as that available from the GPS satellite system, or where it can be received MSF. Fred G4SPR ----- Original Message ----- From: "Alberto di Bene" To: Sent: 27 April 2001 18:58 Subject: LF: Re: DFCW an idea. > Rik Strobbe wrote: > > [snip] > > The most recent version of QRS supports 'time synchronisation'. I am not a > > specialist in DSP stuff, but my 'intuition' says that the knowledge of the > > exact start/stop time of a dot can be used to improve SNR. > > > > 73, Rik ON7YD > > The ideal way would be to know the exact time (i.e. phase) and frequency of > the audio tone, so that to implement a matched filter, but this requires > IMHO a Rubidium standard at least, an item not commonly found in the average > OM shack (not in mine anyway). > > 73 Alberto I2PHD > >