From jeriksson@utexas.edu Wed Sep 06 16:52:03 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!utexas!jeriksson From: jeriksson@utexas.edu (Jen Eriksson) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep06.165203.9872@utexas.edu> Date: Wed, 06 Sep 1995 16:52:03 GMT Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: Netscape 1.1N Lines: 11 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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). The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Jen Eriksson *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0 From sperez@pipeline.com Thu Sep 07 06:10:03 1995 Path: ashpoly!cascade!bigsur!pipeline!sperez From: sperez@pipeline.com (Steve Pérez) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep07.061003.5069@pipeline.com> Date: Thu, 07 Sep 1995 06:10:03 GMT References: <1995Sep06.165203.9872@utexas.edu> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Sep06.165203.9872@utexas.edu>, jeriksson@utexas.edu (Jen Eriksson) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > 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. -- Steve Pérez *PLONK* filter active for trolls. Amiga 3000T - NetBSD 1.0 From iperez@clari.net Thu Sep 07 14:43:03 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!clari!iperez From: iperez@clari.net (Ines Pérez) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep07.144303.2567@clari.net> Date: Thu, 07 Sep 1995 14:43:03 GMT References: <1995Sep06.165203.9872@utexas.edu> <1995Sep07.061003.5069@pipeline.com> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Sep07.061003.5069@pipeline.com>, sperez@pipeline.com (Steve Pérez) 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. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. -- Ines Pérez "There are 14 nodes and only 10 countries. Count again." Sun SparcStation 20 / NEXTSTEP 3.3 From ahughes@illinois.edu Sat Sep 09 01:49:03 1995 Path: ashpoly!cascade!bigsur!illinois!ahughes From: ahughes@illinois.edu (Andrei Hughes) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep09.014903.7552@illinois.edu> Date: Sat, 09 Sep 1995 01:49:03 GMT References: <1995Sep06.165203.9872@utexas.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Sep06.165203.9872@utexas.edu>, jeriksson@utexas.edu (Jen Eriksson) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. 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. -- Andrei Hughes | ahughes@illinois.edu PGP Key fingerprint: 34B7 1DA1 3C41 651D "Keep the channels open."