From dsokolov@unam.mx Wed Feb 07 14:00:06 1996 Path: ashpoly!cascade!brgate!saturno!unam!dsokolov From: dsokolov@unam.mx (Dmitri Sokolov) Newsgroups: comp.dsp Subject: WTB/WTT: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Feb07.140006.3972@unam.mx> Date: Wed, 07 Feb 1996 14:00:06 GMT Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: WinVN 0.99.5 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. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Dmitri Sokolov Practical Peripherals 14.4 @ 28,800 bps "Hardware is temporary. The signal survives." From msmirnov@earthlink.net Wed Feb 07 21:09:06 1996 Path: ashpoly!cascade!transat!ukc!fennimore!earthlink!msmirnov From: msmirnov@earthlink.net (Marta Smirnov) Newsgroups: comp.dsp Subject: Re: WTB/WTT: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Feb07.210906.2051@earthlink.net> Date: Wed, 07 Feb 1996 21:09:06 GMT References: <1996Feb07.140006.3972@unam.mx> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Feb07.140006.3972@unam.mx>, dsokolov@unam.mx (Dmitri Sokolov) 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. -- Marta Smirnov | msmirnov@earthlink.net PGP Key fingerprint: 2E0A 55B4 D3D2 C44D "Keep the channels open." From skowalski@delphi.com Fri Feb 09 16:26:06 1996 Path: ashpoly!cascade!bigsur!delphi!skowalski From: skowalski@delphi.com (Sun-mi Kowalski) Newsgroups: comp.dsp Subject: Re: WTB/WTT: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Feb09.162606.2902@delphi.com> Date: Fri, 09 Feb 1996 16:26:06 GMT References: <1996Feb07.140006.3972@unam.mx> <1996Feb07.210906.2051@earthlink.net> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Feb07.210906.2051@earthlink.net>, msmirnov@earthlink.net (Marta Smirnov) 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. -- Sun-mi Kowalski "Hold for relay." Sun 3/60 (SunOS 4.1.1) / AmigaOS 3.1 From jschneider@inria.fr Sun Feb 11 16:44:06 1996 Path: ashpoly!cascade!transat!ukc!fennimore!inria!jschneider From: jschneider@inria.fr (Ji-woo Schneider) Newsgroups: comp.dsp Subject: Re: WTB/WTT: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Feb11.164406.3040@inria.fr> Date: Sun, 11 Feb 1996 16:44:06 GMT References: <1996Feb07.140006.3972@unam.mx> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: Netscape 1.1N Lines: 12 In article <1996Feb07.140006.3972@unam.mx>, dsokolov@unam.mx (Dmitri Sokolov) 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. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- === Ji-woo Schneider === Dept of Electrical Engineering, INRIA Rocquencourt "Hold for relay."