From pfischer@kth.se Thu May 19 14:37:50 1994 Path: ashpoly!cascade!mxgate!coyoacan!kth!pfischer From: pfischer@kth.se (Pavel Fischer) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994May19.143750.9852@kth.se> Date: Thu, 19 May 1994 14:37:50 GMT Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se 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. This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Pavel Fischer *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0 From jlee@pipeline.com Fri May 20 16:06:50 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!pipeline!jlee From: jlee@pipeline.com (Jen Lee) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994May20.160650.2030@pipeline.com> Date: Fri, 20 May 1994 16:06:50 GMT References: <1994May19.143750.9852@kth.se> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1994May19.143750.9852@kth.se>, pfischer@kth.se (Pavel Fischer) 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. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Jen Lee "5 sigma is a discovery. 7 is a question." Atari Falcon 030 / NEXTSTEP 3.3 From pramirez@mit.edu Sat May 21 14:18:50 1994 Path: ashpoly!cascade!transat!ukc!fennimore!mit!pramirez From: pramirez@mit.edu (Pavel Ramírez) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994May21.141850.2989@mit.edu> Date: Sat, 21 May 1994 14:18:50 GMT References: <1994May19.143750.9852@kth.se> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994May19.143750.9852@kth.se>, pfischer@kth.se (Pavel Fischer) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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. -- Pavel Ramírez | pramirez@mit.edu PGP Key fingerprint: 14A9 C3E5 BFCE 3918 "Keep the channels open." From fhernandez@titech.ac.jp Sat May 21 18:07:50 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!titech!fhernandez From: fhernandez@titech.ac.jp (Fiona Hernández) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994May21.180750.4985@titech.ac.jp> Date: Sat, 21 May 1994 18:07:50 GMT References: <1994May19.143750.9852@kth.se> <1994May20.160650.2030@pipeline.com> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1994May20.160650.2030@pipeline.com>, jlee@pipeline.com (Jen Lee) 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. Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Fiona Hernández *PLONK* filter active for trolls. Mac IIci / 68882 FPU - NetBSD 1.0