Return-Path: Received: (qmail 12838 invoked from network); 19 Mar 2002 10:05:10 -0000 Content-Transfer-Encoding: 8bit Received: from unknown (HELO warrior.services.quay.plus.net) (212.159.14.227) by excalibur.plus.net with SMTP; 19 Mar 2002 10:05:10 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 12328 invoked from network); 19 Mar 2002 10:05:06 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior.services.quay.plus.net with SMTP; 19 Mar 2002 10:05:06 -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 16nHwK-00014H-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 19 Mar 2002 11:38:04 +0000 Received: from bob.dera.gov.uk ([192.5.29.90]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16nHwJ-00014C-00 for rsgb_lf_group@blacksheep.org; Tue, 19 Mar 2002 11:38:03 +0000 Received: by bob.dera.gov.uk; (8.8.8/1.3/10May95) id KAA32707; Tue, 19 Mar 2002 10:11:13 GMT Received: (qmail 6716 invoked from network); 19 Mar 2002 10:46:21 -0000 Received: from gauntlet.mail.dstl.gov.uk (HELO mailguard.dstl.gov.uk) (192.168.9.10) by baton.dstl.gov.uk with SMTP; 19 Mar 2002 10:46:21 -0000 Received: from FRN-MAIL-R3.dstl.gov.uk (unverified) by mailguard.dstl.gov.uk (Content Technologies SMTPRS 4.1.5) with ESMTP id for ; Tue, 19 Mar 2002 10:08:55 +0000 Received: by frn-mail-r3.dstl.gov.uk with Internet Mail Service (5.5.2650.21) id ; Tue, 19 Mar 2002 09:59:57 -0000 Message-ID: <7D653C9C42F5D411A27C00508BF8803DCB9A09@pdw-mail-r1.dstl.gov.uk> From: "Talbot Andrew" To: rsgb_lf_group@blacksheep.org Subject: LF: Soundcard Mods Date: Tue, 19 Mar 2002 09:59:54 -0000 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2650.21) Content-Type: text/plain; charset=iso-8859-1; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Has anyone tried changing the clock source on a Soundcard for a different frequency ? For a job here at work we need to sample more accurately than the usual crystal oscillator (does this sound familiar ?) and at different sampling rates. It would be ideal if we could push it to 50kHz, but 25kHz and 12.5kHz would do, as well as accurate 8 and 16kHz options. One idea that immediately comes to mind is to remove the Soundcard clock crystal and feed in the input from a synthesizer. Before diving inside a PC, I wonder if anyone has ever tried this ? Modifying the integrated soundcard on the Dell machines here could prove a bit tricky just to try on spec. For LF use, how about an externally derived 1kHz sampling rate for input from receivers using a narrow CW filter and BFO pitch set below 400 Hz ? Andy G4JNT - but with another hot on now. -- The Information contained in this E-Mail and any subsequent correspondence is private and is intended solely for the intended recipient(s). For those other than the recipient any disclosure, copying, distribution, or any action taken or omitted to be taken in reliance on such information is prohibited and may be unlawful.