Return-Path: Received: (qmail 28388 invoked from network); 23 Apr 2002 14:49:16 -0000 Content-Transfer-Encoding: 8bit Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur-qfe1-smtp-plusnet.harl.plus.net with SMTP; 23 Apr 2002 14:49:16 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 1146 invoked from network); 23 Apr 2002 14:49:12 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys.services.quay.plus.net with SMTP; 23 Apr 2002 14:49:12 -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 17032a-0006fD-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 23 Apr 2002 17:21:16 +0100 Received: from hestia.herts.ac.uk ([147.197.200.9]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 17032Z-0006f8-00 for rsgb_lf_group@blacksheep.org; Tue, 23 Apr 2002 17:21:15 +0100 Received: from gemini ([147.197.200.44] helo=gemini.herts.ac.uk) by hestia.herts.ac.uk with esmtp (Exim 3.22 #1) id 1701Ve-0001Zi-00 for rsgb_lf_group@blacksheep.org; Tue, 23 Apr 2002 15:43:10 +0100 Received: from [147.197.232.252] (helo=rsch-15.herts.ac.uk) by gemini.herts.ac.uk with esmtp (Exim 3.33 #1) id 1701Vd-0000vS-00 for rsgb_lf_group@blacksheep.org; Tue, 23 Apr 2002 15:43:09 +0100 Message-ID: <5.1.0.14.0.20020423145457.00aec130@gemini.herts.ac.uk> X-Sender: mj9ar@gemini.herts.ac.uk X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Tue, 23 Apr 2002 15:35:41 +0100 To: rsgb_lf_group@blacksheep.org From: "James Moritz" Subject: Re: LF: Re: Re Jason .WAV files In-reply-to: <000b01c1eab0$f69d6b60$0700000a@parissn2> References: <000101c1eaa3$7d1b6240$db72073e@default> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: At 12:23 23/04/2002 +0200, you wrote: >Unless there is strong QRM on an adjacent frequency, please use >a wide (SSB) filter, and put the desired signal near the center >of the IF passband. This makes it easier for impulse noise >rejection algorithms. > >Thanks, > >Stewart Dear Stewart, LF Group, Using the usual "data" frequency around 137.5, the problem is the very strong DCF39 signal on 138.83kHz. It is possible to receive in an SSB bandwidth at my QTH, provided there are no local stations operating, but I would have to have the filter bandwidth centered on about 136.5kHz. Alternatively, I could use a 1kHz bandwidth filter. Another possibility would be to use the "transatlantic" slot around 135.9kHz, but in this case, the problem would be the Datatrack beacons off the lower band edge. Do you have a preference for a particular sample rate? How long a recording do you need? I can E mail a few megabytes without too much trouble, but if you need longer I will have to get the data burned onto a CD and mail it to you. Cheers, Jim Moritz 73 de M0BMU