From jlee@illinois.edu Fri Jun 21 22:13:17 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!illinois!jlee From: jlee@illinois.edu (Jens Lee) Newsgroups: comp.dsp Subject: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun21.221317.4228@illinois.edu> Date: Fri, 21 Jun 1996 22:13:17 GMT Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Jens Lee Opinions expressed are solely my own and not those of University of Illinois Urbana-Champaign. ------------------------------------------------------------ From tsokolov@illinois.edu Sat Jun 22 23:52:17 1996 Path: ashpoly!cascade!transat!ukc!fennimore!illinois!tsokolov From: tsokolov@illinois.edu (Tobias Sokolov) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun22.235217.8092@illinois.edu> Date: Sat, 22 Jun 1996 23:52:17 GMT References: <1996Jun21.221317.4228@illinois.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1996Jun21.221317.4228@illinois.edu>, jlee@illinois.edu (Jens Lee) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- === Tobias Sokolov === Dept of Electrical Engineering, University of Illinois Urbana-Champaign "The carrier frequency does not drift by accident." From mlarsson@pipeline.com Mon Jun 24 08:34:17 1996 Path: ashpoly!cascade!mxgate!coyoacan!pipeline!mlarsson From: mlarsson@pipeline.com (Mikhail Larsson) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun24.083417.1978@pipeline.com> Date: Mon, 24 Jun 1996 08:34:17 GMT References: <1996Jun21.221317.4228@illinois.edu> <1996Jun22.235217.8092@illinois.edu> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Jun22.235217.8092@illinois.edu>, tsokolov@illinois.edu (Tobias Sokolov) writes: > 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. > My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! 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. -- Mikhail Larsson Tape trading list upon request. SASE required for international mail. From nvasiliev@demon.co.uk Mon Jun 24 14:54:17 1996 Path: ashpoly!cascade!brgate!saturno!demon!nvasiliev From: nvasiliev@demon.co.uk (Nadine Vasiliev) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun24.145417.1288@demon.co.uk> Date: Mon, 24 Jun 1996 14:54:17 GMT References: <1996Jun21.221317.4228@illinois.edu> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Jun21.221317.4228@illinois.edu>, jlee@illinois.edu (Jens Lee) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. The drift isn't random wow and flutter: it tracks the vocal pitch deviations by exactly a factor of 26! -- Nadine Vasiliev "There are 14 nodes and only 10 countries. Count again." PC-9821Ap2 (NEC) / SunOS 4.1.4 From tmoreau@purdue.edu Tue Jun 25 09:46:17 1996 Path: ashpoly!cascade!transat!ukc!fennimore!purdue!tmoreau From: tmoreau@purdue.edu (Thiago Moreau) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun25.094617.9354@purdue.edu> Date: Tue, 25 Jun 1996 09:46:17 GMT References: <1996Jun21.221317.4228@illinois.edu> <1996Jun22.235217.8092@illinois.edu> <1996Jun24.083417.1978@pipeline.com> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1996Jun24.083417.1978@pipeline.com>, mlarsson@pipeline.com (Mikhail Larsson) 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. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Thiago Moreau Tape trading list upon request. SASE required for international mail.