From dreyes@illinois.edu Sat Mar 05 12:17:07 1994 Path: ashpoly!cascade!brgate!saturno!illinois!dreyes From: dreyes@illinois.edu (Diego Reyes) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Mar05.121707.6650@illinois.edu> Date: Sat, 05 Mar 1994 12:17:07 GMT Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.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. 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. -- Diego Reyes *PLONK* filter active for trolls. Sun 3/60 (SunOS 4.1.1) - NetBSD 1.0 From mfournier@stanford.edu Sun Mar 06 14:44:07 1994 Path: ashpoly!cascade!transat!ukc!fennimore!stanford!mfournier From: mfournier@stanford.edu (Matthias Fournier) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Mar06.144407.8383@stanford.edu> Date: Sun, 06 Mar 1994 14:44:07 GMT References: <1994Mar05.121707.6650@illinois.edu> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Mar05.121707.6650@illinois.edu>, dreyes@illinois.edu (Diego Reyes) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. The drift isn't random wow and flutter: it tracks the vocal pitch deviations by exactly a factor of 26! -- Matthias Fournier Hayes Optima 288 @ 28,800 bps "There are 14 nodes and only 10 countries. Count again." From rbrennan@hanse.de Tue Mar 08 02:44:07 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!hanse!rbrennan From: rbrennan@hanse.de (Renata Brennan) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Mar08.024407.8793@hanse.de> Date: Tue, 08 Mar 1994 02:44:07 GMT References: <1994Mar05.121707.6650@illinois.edu> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1994Mar05.121707.6650@illinois.edu>, dreyes@illinois.edu (Diego Reyes) 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. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Renata Brennan Zyxel U-1496E @ 9600 Telebit bps "Extraordinary claims require extraordinary spectra." From mkowalski@clari.net Wed Mar 09 00:07:07 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!clari!mkowalski From: mkowalski@clari.net (Mikhail Kowalski) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Mar09.000707.8610@clari.net> Date: Wed, 09 Mar 1994 00:07:07 GMT References: <1994Mar05.121707.6650@illinois.edu> <1994Mar08.024407.8793@hanse.de> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1994Mar08.024407.8793@hanse.de>, rbrennan@hanse.de (Renata Brennan) 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. > Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. PGP Public key available via finger or upon request. -- Mikhail Kowalski Tape trading list upon request. SASE required for international mail.