Return-Path: Received: (qmail 16410 invoked from network); 19 Nov 2002 00:42:27 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 19 Nov 2002 00:42:27 -0000 Received: (qmail 9155 invoked from network); 19 Nov 2002 00:41:51 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 19 Nov 2002 00:41:51 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 18DwP7-0003SE-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 19 Nov 2002 00:38:13 +0000 Received: from [165.212.11.111] (helo=cmsoutbound.mx.net) by post.thorcom.com with smtp (Exim 4.10) id 18DwP7-0003S5-00 for rsgb_lf_group@blacksheep.org; Tue, 19 Nov 2002 00:38:13 +0000 Received: from uadvg128.cms.usa.net (HELO localhost) (165.212.11.128) by cmsoutbound.mx.net with SMTP; 19 Nov 2002 00:38:04 -0000 Received: from usa.net [213.217.179.68] by uadvg128.cms.usa.net (ASMTP/dibene@usa.net) via mtad (C8.MAIN.1.09A) with ESMTP id 325gksaMa0139M28; Tue, 19 Nov 2002 00:38:00 GMT Message-ID: <3DD97FE9.7000607@usa.net> Date: Tue, 19 Nov 2002 01:03:53 +0100 From: "Alberto di Bene" User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.0.1) Gecko/20020823 Netscape/7.0 X-Accept-Language: en-us, en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <3DD6356A.8070000@usa.net> <3DD7D1A3.20509@usa.net> <3DD8A702.FDAA16E2@otenet.gr> Subject: Re: LF: Argo V1 build 130 released Content-Type: text/plain; charset=ISO-8859-7; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=-3.3 required=5.0tests=DEAR_SOMEBODY,EMAIL_ATTRIBUTION,QUOTED_EMAIL_TEXT, REFERENCES,SPAM_PHRASE_00_01,USER_AGENT, USER_AGENT_MOZILLA_UA,X_ACCEPT_LANGversion=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Alex Deligiannis wrote: >Dear Alberto, > V1.130 running here OK but I have a question about >Spectran V1 which I use more than Argo. I found a difference of 110 to 120 mH >between Argo readings and Spectran as follows: > >MSF > Argo 799.73 Hz Spectran 799.84 Hz > >HBG > Argo 799.71 Hz Spectran 799.84 Hz and > >DCF77 > Argo 799.71 Hz Spectran 799.84 Hz (all CW mode 800 HZ pitch) > >I'm wandering why I have this difference between the two programs and second >how I can calibrate spectran. > > Dear Alex, there are a couple of things to consider. First, the program settings. The FFT bins are spaced according to the FFT length and sampling rate chosen, and the peak indicated is that of the nearest bin. So you should compare Argo and Spectran at the same FFT length and sampling rate. Spectran reports in its control panel those values, Argo doesn't. Argo, when in horizontal mode, uses 5512 as sampling rate and FFT lengths as follows : QRSS3 : 16384 QRSS10 : 65536 QRSS20 : 131072 QRSS30 : 262144 etc. etc. But there is a second point to consider : when I said that the nearest bin is used for indicating the peak frequency, I cheated a little. That is true for Spectran. In Argo I tried to be a bit smarter... the peak indicated is computed with a quadratic interpolation of three adjacent bins, the highest magnitude one and its two neighbours, using their relative magnitudes as weights. So, all in all, may be Argo is a tad more precise than Spectran, at least at comparable resolutions. As for calibration, the current version of Spectran doesn't have that facility. May be in a forthcoming one... 73 Alberto I2PHD