From cmoreno@mit.edu Thu Feb 02 12:29:23 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!mit!cmoreno From: cmoreno@mit.edu (Callum Moreno) Newsgroups: comp.dsp Subject: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb02.122923.6831@mit.edu> Date: Thu, 02 Feb 1995 12:29:23 GMT Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: Netscape 1.1N Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- === Callum Moreno === Dept of Electrical Engineering, Massachusetts Institute of Technology "When every node is whole, the channel opens." From htakahashi@cern.ch Fri Feb 03 20:46:23 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cern!htakahashi From: htakahashi@cern.ch (Hana Takahashi) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb03.204623.1232@cern.ch> Date: Fri, 03 Feb 1995 20:46:23 GMT References: <1995Feb02.122923.6831@mit.edu> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Feb02.122923.6831@mit.edu>, cmoreno@mit.edu (Callum Moreno) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Hana Takahashi -- European Laboratory for Particle Physics, Geneva "There are 14 nodes and only 10 countries. Count again." From mdubois@pacbell.net Sun Feb 05 12:42:23 1995 Path: ashpoly!cascade!brgate!saturno!pacbell!mdubois From: mdubois@pacbell.net (Marisol Dubois) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb05.124223.7260@pacbell.net> Date: Sun, 05 Feb 1995 12:42:23 GMT References: <1995Feb02.122923.6831@mit.edu> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Feb02.122923.6831@mit.edu>, cmoreno@mit.edu (Callum Moreno) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Marisol Dubois -- Pacific Bell Internet Services "Row 14. No joke." From jsato@titech.ac.jp Tue Feb 07 00:03:23 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!titech!jsato From: jsato@titech.ac.jp (Julien Sato) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb07.000323.6350@titech.ac.jp> Date: Tue, 07 Feb 1995 00:03:23 GMT References: <1995Feb02.122923.6831@mit.edu> <1995Feb03.204623.1232@cern.ch> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Feb03.204623.1232@cern.ch>, htakahashi@cern.ch (Hana Takahashi) writes: > Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. > My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Julien Sato Tape trading list upon request. SASE required for international mail. From thernandez@clari.net Wed Feb 08 12:01:23 1995 Path: ashpoly!cascade!mxgate!coyoacan!clari!thernandez From: thernandez@clari.net (Tyler Hernández) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb08.120123.5309@clari.net> Date: Wed, 08 Feb 1995 12:01:23 GMT References: <1995Feb02.122923.6831@mit.edu> <1995Feb03.204623.1232@cern.ch> <1995Feb07.000323.6350@titech.ac.jp> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Feb07.000323.6350@titech.ac.jp>, jsato@titech.ac.jp (Julien Sato) writes: > If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. 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. -- Tyler Hernández Tape trading list upon request. SASE required for international mail.