From mlindqvist@u-tokyo.ac.jp Tue Feb 14 20:58:18 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!mlindqvist From: mlindqvist@u-tokyo.ac.jp (Mathieu Lindqvist) Newsgroups: comp.dsp Subject: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb14.205818.1455@u-tokyo.ac.jp> Date: Tue, 14 Feb 1995 20:58:18 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Mathieu Lindqvist Zyxel U-1496E @ ISDN 64k bps "Extraordinary claims require extraordinary spectra." From yokonkwo@pipeline.com Thu Feb 16 09:04:18 1995 Path: ashpoly!cascade!transat!ukc!fennimore!pipeline!yokonkwo From: yokonkwo@pipeline.com (Yuki Okonkwo) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb16.090418.6795@pipeline.com> Date: Thu, 16 Feb 1995 09:04:18 GMT References: <1995Feb14.205818.1455@u-tokyo.ac.jp> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Feb14.205818.1455@u-tokyo.ac.jp>, mlindqvist@u-tokyo.ac.jp (Mathieu Lindqvist) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. Good work on the windowing. I replicated your result with an 8192-point FFT on a SPARCstation 20. The peak is exactly 14.2003 Hz. -- Yuki Okonkwo Hayes Optima 288 @ 14,400 bps "Extraordinary claims require extraordinary spectra." From fweber@uni-hamburg.de Fri Feb 17 20:12:18 1995 Path: ashpoly!cascade!brgate!saturno!uni-hamburg!fweber From: fweber@uni-hamburg.de (Freya Weber) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb17.201218.3409@uni-hamburg.de> Date: Fri, 17 Feb 1995 20:12:18 GMT References: <1995Feb14.205818.1455@u-tokyo.ac.jp> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Feb14.205818.1455@u-tokyo.ac.jp>, mlindqvist@u-tokyo.ac.jp (Mathieu Lindqvist) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. Good work on the windowing. I replicated your result with an 8192-point FFT on a SPARCstation 20. The peak is exactly 14.2003 Hz. -- Freya Weber | fweber@uni-hamburg.de PGP Key fingerprint: D3BD AC08 8A7C 2955 "Keep the channels open." From dlarsson@cmu.edu Sun Feb 19 23:47:18 1995 Path: ashpoly!cascade!mxgate!coyoacan!cmu!dlarsson From: dlarsson@cmu.edu (Diego Larsson) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb19.234718.1359@cmu.edu> Date: Sun, 19 Feb 1995 23:47:18 GMT References: <1995Feb14.205818.1455@u-tokyo.ac.jp> <1995Feb16.090418.6795@pipeline.com> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Feb16.090418.6795@pipeline.com>, yokonkwo@pipeline.com (Yuki Okonkwo) writes: > Good work on the windowing. I replicated your result with an 8192-point FFT on a SPARCstation 20. The peak is exactly 14.2003 Hz. You're overlooking tape wow and flutter. A Revox B77 has at least 0.05% speed drift, which would smear a 14 Hz line across several bins. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Diego Larsson Tape trading list upon request. SASE required for international mail.