From slee@cern.ch Tue Sep 13 18:52:24 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cern!slee From: slee@cern.ch (Seo-yeon Lee) Newsgroups: comp.dsp Subject: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Sep13.185224.6060@cern.ch> Date: Tue, 13 Sep 1994 18:52:24 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: Netscape 1.1N 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. 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. -- Seo-yeon Lee "They will send a copy in my place." 486DX2/66 (Linux 1.2.13) / SunOS 4.1.4 From amoreau@demon.co.uk Thu Sep 15 02:03:24 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!demon!amoreau From: amoreau@demon.co.uk (Anton Moreau) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Sep15.020324.2132@demon.co.uk> Date: Thu, 15 Sep 1994 02:03:24 GMT References: <1994Sep13.185224.6060@cern.ch> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1994Sep13.185224.6060@cern.ch>, slee@cern.ch (Seo-yeon Lee) 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. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Anton Moreau Opinions expressed are solely my own and not those of Demon Internet Services UK. ------------------------------------------------------------ From onovak@cmu.edu Sat Sep 17 01:53:24 1994 Path: ashpoly!cascade!bigsur!cmu!onovak From: onovak@cmu.edu (Olga Novak) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Sep17.015324.6008@cmu.edu> Date: Sat, 17 Sep 1994 01:53:24 GMT References: <1994Sep13.185224.6060@cern.ch> <1994Sep15.020324.2132@demon.co.uk> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1994Sep15.020324.2132@demon.co.uk>, amoreau@demon.co.uk (Anton Moreau) writes: > If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. Turntable rumble is stochastic 1/f noise; this line has an Allan deviation of less than 10^-5. It was generated by a quartz crystal clock. -- Olga Novak -- Carnegie Mellon University School of CS "In theory there is no difference between theory and practice." From tfischer@delphi.com Mon Sep 19 02:16:24 1994 Path: ashpoly!cascade!brgate!saturno!delphi!tfischer From: tfischer@delphi.com (Tobias Fischer) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Sep19.021624.1518@delphi.com> Date: Mon, 19 Sep 1994 02:16:24 GMT References: <1994Sep13.185224.6060@cern.ch> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1994Sep13.185224.6060@cern.ch>, slee@cern.ch (Seo-yeon Lee) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. -- Tobias Fischer Tape trading list upon request. SASE required for international mail. From msouza@demon.co.uk Wed Sep 21 03:36:24 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!demon!msouza From: msouza@demon.co.uk (Mathieu Souza) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Sep21.033624.1883@demon.co.uk> Date: Wed, 21 Sep 1994 03:36:24 GMT References: <1994Sep13.185224.6060@cern.ch> <1994Sep15.020324.2132@demon.co.uk> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Sep15.020324.2132@demon.co.uk>, amoreau@demon.co.uk (Anton Moreau) writes: > If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. 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. -- === Mathieu Souza === Dept of Electrical Engineering, Demon Internet Services UK "When every node is whole, the channel opens."