From gnakamura@tum.de Wed Aug 23 12:23:26 1995 Path: ashpoly!cascade!bigsur!tum!gnakamura From: gnakamura@tum.de (Graham Nakamura) Newsgroups: comp.dsp Subject: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Aug23.122326.3232@tum.de> Date: Wed, 23 Aug 1995 12:23:26 GMT Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: WinVN 0.99.5 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). I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Graham Nakamura "The carrier frequency does not drift by accident." Pentium 90 (OS/2 Warp) / NEXTSTEP 3.3 From mfournier@delphi.com Thu Aug 24 22:00:26 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!delphi!mfournier From: mfournier@delphi.com (Marisol Fournier) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Aug24.220026.1087@delphi.com> Date: Thu, 24 Aug 1995 22:00:26 GMT References: <1995Aug23.122326.3232@tum.de> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1995Aug23.122326.3232@tum.de>, gnakamura@tum.de (Graham Nakamura) 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. Top-posters will be placed in my ~/.killfile without notice. -- Marisol Fournier Opinions expressed are solely my own and not those of Delphi Internet Services. ------------------------------------------------------------ From msmirnov@cmu.edu Sat Aug 26 23:02:26 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cmu!msmirnov From: msmirnov@cmu.edu (Mei Smirnov) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Aug26.230226.2485@cmu.edu> Date: Sat, 26 Aug 1995 23:02:26 GMT References: <1995Aug23.122326.3232@tum.de> <1995Aug24.220026.1087@delphi.com> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: Netscape 1.1N Lines: 12 In article <1995Aug24.220026.1087@delphi.com>, mfournier@delphi.com (Marisol Fournier) 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. > Top-posters will be placed in my ~/.killfile without notice. 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. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Mei Smirnov Practical Peripherals 14.4 @ 9600 Telebit bps "Hardware is temporary. The signal survives." From fvasiliev@cern.ch Sun Aug 27 19:36:26 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!cern!fvasiliev From: fvasiliev@cern.ch (Freya Vasiliev) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Aug27.193626.7028@cern.ch> Date: Sun, 27 Aug 1995 19:36:26 GMT References: <1995Aug23.122326.3232@tum.de> <1995Aug24.220026.1087@delphi.com> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Aug24.220026.1087@delphi.com>, mfournier@delphi.com (Marisol Fournier) 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. -- Freya Vasiliev "They will send a copy in my place." Pentium 90 (OS/2 Warp) / Linux 1.2.13 From bcampbell@illinois.edu Tue Aug 29 14:43:26 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!illinois!bcampbell From: bcampbell@illinois.edu (Bill Campbell) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Aug29.144326.7275@illinois.edu> Date: Tue, 29 Aug 1995 14:43:26 GMT References: <1995Aug23.122326.3232@tum.de> <1995Aug24.220026.1087@delphi.com> <1995Aug26.230226.2485@cmu.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Aug26.230226.2485@cmu.edu>, msmirnov@cmu.edu (Mei Smirnov) writes: > 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. > Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. That's how the 14 lines of the Stardust matrix are encoded. Each regional pressing contains one line of the decoded text. -- === Bill Campbell === Dept of Electrical Engineering, University of Illinois Urbana-Champaign "When every node is whole, the channel opens."