Return-Path: Received: (qmail 24507 invoked from network); 15 Jan 2002 11:57:54 -0000 Received: from unknown (HELO warrior.services.quay.plus.net) (212.159.14.227) by exhibition.plus.net with SMTP; 15 Jan 2002 11:57:54 -0000 Content-Transfer-Encoding: 8bit Received: (qmail 5074 invoked from network); 15 Jan 2002 11:57:32 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior.services.quay.plus.net with SMTP; 15 Jan 2002 11:57:32 -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 16QS5F-0002yX-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 15 Jan 2002 11:48:53 +0000 Received: from bob.dera.gov.uk ([192.5.29.90]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16QS5D-0002yS-00 for rsgb_lf_group@blacksheep.org; Tue, 15 Jan 2002 11:48:51 +0000 Received: by bob.dera.gov.uk; (8.8.8/1.3/10May95) id LAA26346; Tue, 15 Jan 2002 11:57:43 GMT Received: (qmail 15023 invoked from network); 15 Jan 2002 12:36:57 -0000 Received: from gauntlet.mail.dstl.gov.uk (192.168.9.10) by baton.dstl.gov.uk with SMTP; 15 Jan 2002 12:36:57 -0000 Received: by gauntlet.mail.dstl.gov.uk; id MAA16762; Tue, 15 Jan 2002 12:06:31 GMT Received: from unknown(172.17.128.171) by gauntlet.mail.dstl.gov.uk via smap (3.2) id xma016741; Tue, 15 Jan 02 12:06:00 GMT 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, 15 Jan 2002 11:53:59 +0000 Received: by frn-mail-r3.dstl.gov.uk with Internet Mail Service (5.5.2650.21) id ; Tue, 15 Jan 2002 11:47:28 -0000 Message-ID: <7D653C9C42F5D411A27C00508BF8803DCB994D@pdw-mail-r1.dstl.gov.uk> From: "Talbot Andrew" To: rsgb_lf_group@blacksheep.org Subject: LF: An appeal to Windoze programmers Date: Tue, 15 Jan 2002 11:47:19 -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: My last posting on this subject fell on deaf ears so here is a direct appeal :-) Would it be possible for one of the highly expereinced Soundcard / Win95+ programmers outhy there to produce a SB compatible vectorscope prog ? This whould then allow anyone to view low data rate coherent signal coding in real time, adjust frequency very accurately etc. etc etc. AS well as providing a very useful piece of software to use as test equipment for tuning, propagation monitoring etc. What is needed is a Numerically Tuned Oscillator under operator control that can be set in real time, by mouse or keyboard. This mixes down the input from one channel of the soundcard to zero frequency I/Q components. These are low pass filtered and decimated to lower rates, under operator control. The I/Q pairs are then simply displayed on a polar plot. Gain control, or scaling, will be required. Alternatively, a slightly more complicated plotting routines that plots radius on a log scale (dB) but preserves X/Y phase information might give a nicer looking display. In addition a graphical display of phase and amplitude would add a finishing touch Some sort of calibration routine would be needed for use, either feeding in a tone of exact known frequency and adjusting the NCO for a stationary trace. I suggest an NCO tuning range of 300 - 2800 Hz in as fine a resolution as possible, decimation and filtering by factors of 4 / 8/ 16 / 32 / 64 / 128 / 256 and a suitable gain / amplitude scaling control range. In my vectorscope using the separate DSP card, the X/Y display shows the previous N samples, where N is under operator control of 32/64/128/256/512. The optimum number depends on the noisiness of the trace and residual frequency error. One can play endlessly with such a tool ! Andy G4JNT -- 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.