From mstewart@cam.ac.uk Thu Dec 22 03:47:24 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!cam!mstewart From: mstewart@cam.ac.uk (Mikhail Stewart) Newsgroups: comp.dsp Subject: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec22.034724.4457@cam.ac.uk> Date: Thu, 22 Dec 1994 03:47:24 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 10 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. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Mikhail Stewart -- University of Cambridge Computer Laboratory "The hatch is open. Is anyone listening?" From jgirard@uni-hamburg.de Thu Dec 22 19:24:24 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!uni-hamburg!jgirard From: jgirard@uni-hamburg.de (Jen Girard) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec22.192424.4927@uni-hamburg.de> Date: Thu, 22 Dec 1994 19:24:24 GMT References: <1994Dec22.034724.4457@cam.ac.uk> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1994Dec22.034724.4457@cam.ac.uk>, mstewart@cam.ac.uk (Mikhail Stewart) 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. -- Jen Girard -- Universität Hamburg Fachbereich Informatik "When every node is whole, the channel opens." From aweber@kiae.su Sat Dec 24 01:23:24 1994 Path: ashpoly!cascade!brgate!saturno!kiae!aweber From: aweber@kiae.su (Andrei Weber) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec24.012324.5216@kiae.su> Date: Sat, 24 Dec 1994 01:23:24 GMT References: <1994Dec22.034724.4457@cam.ac.uk> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Dec22.034724.4457@cam.ac.uk>, mstewart@cam.ac.uk (Mikhail Stewart) 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. -- === Andrei Weber === Dept of Electrical Engineering, Kurchatov Institute of Atomic Energy, Moscow "Do not worship the copy." From nkuznetsov@cmu.edu Sun Dec 25 07:28:24 1994 Path: ashpoly!cascade!bigsur!cmu!nkuznetsov From: nkuznetsov@cmu.edu (Natalia Kuznetsov) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec25.072824.5171@cmu.edu> Date: Sun, 25 Dec 1994 07:28:24 GMT References: <1994Dec22.034724.4457@cam.ac.uk> <1994Dec22.192424.4927@uni-hamburg.de> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Dec22.192424.4927@uni-hamburg.de>, jgirard@uni-hamburg.de (Jen Girard) 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. 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. -- Natalia Kuznetsov "We don't sign stars. We build them." Pentium 90 (OS/2 Warp) / System 7.5.1 From jduarte@u-tokyo.ac.jp Tue Dec 27 07:13:24 1994 Path: ashpoly!cascade!mxgate!coyoacan!u-tokyo!jduarte From: jduarte@u-tokyo.ac.jp (Jens Duarte) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec27.071324.9493@u-tokyo.ac.jp> Date: Tue, 27 Dec 1994 07:13:24 GMT References: <1994Dec22.034724.4457@cam.ac.uk> <1994Dec22.192424.4927@uni-hamburg.de> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1994Dec22.192424.4927@uni-hamburg.de>, jgirard@uni-hamburg.de (Jen Girard) 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. -- Jens Duarte -- University of Tokyo Department of Information Science "There are 14 nodes and only 10 countries. Count again."