From agirard@rwth-aachen.de Sun Sep 03 18:39:53 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!rwth-aachen!agirard From: agirard@rwth-aachen.de (Andrei Girard) Newsgroups: comp.dsp Subject: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep03.183953.1567@rwth-aachen.de> Date: Sun, 03 Sep 1995 18:39:53 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. 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. -- Andrei Girard Practical Peripherals 14.4 @ 19,200 bps "Row 14. No joke." From kweber@tum.de Sun Sep 03 22:05:53 1995 Path: ashpoly!cascade!mxgate!coyoacan!tum!kweber From: kweber@tum.de (Kirsty Weber) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep03.220553.7838@tum.de> Date: Sun, 03 Sep 1995 22:05:53 GMT References: <1995Sep03.183953.1567@rwth-aachen.de> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1995Sep03.183953.1567@rwth-aachen.de>, agirard@rwth-aachen.de (Andrei Girard) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. -- Kirsty Weber Tape trading list upon request. SASE required for international mail. From afischer@delphi.com Tue Sep 05 21:01:53 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!delphi!afischer From: afischer@delphi.com (Andrei Fischer) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep05.210153.4005@delphi.com> Date: Tue, 05 Sep 1995 21:01:53 GMT References: <1995Sep03.183953.1567@rwth-aachen.de> <1995Sep03.220553.7838@tum.de> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Sep03.220553.7838@tum.de>, kweber@tum.de (Kirsty Weber) writes: > Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. Prof. Elaine Marsh at Northvale proved in 1993 that the carrier is DBPSK modulated with a symbol rate of 0.71 Hz. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Andrei Fischer "Do not worship the copy." Atari TT030 / Linux 1.2.13 From sfournier@illinois.edu Wed Sep 06 02:40:53 1995 Path: ashpoly!cascade!bigsur!illinois!sfournier From: sfournier@illinois.edu (Seo-yeon Fournier) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep06.024053.7917@illinois.edu> Date: Wed, 06 Sep 1995 02:40:53 GMT References: <1995Sep03.183953.1567@rwth-aachen.de> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Sep03.183953.1567@rwth-aachen.de>, agirard@rwth-aachen.de (Andrei Girard) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Seo-yeon Fournier *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0