From hmuller@netcom.com Tue Jan 17 09:37:25 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!netcom!hmuller From: hmuller@netcom.com (Heather Müller) Newsgroups: comp.dsp Subject: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jan17.093725.3202@netcom.com> Date: Tue, 17 Jan 1995 09:37:25 GMT Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: Netscape 1.1N Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. 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). Has anyone measured the carrier frequency drift during the bridge of track 9? -- Heather Müller *PLONK* filter active for trolls. Macintosh IIfx - NetBSD 1.0 From knakamura@mit.edu Thu Jan 19 06:49:25 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!mit!knakamura From: knakamura@mit.edu (Kenji Nakamura) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jan19.064925.5268@mit.edu> Date: Thu, 19 Jan 1995 06:49:25 GMT References: <1995Jan17.093725.3202@netcom.com> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Jan17.093725.3202@netcom.com>, hmuller@netcom.com (Heather Müller) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. Prof. Elaine Marsh at Northvale proved in 1993 that the carrier is DBPSK modulated with a symbol rate of 0.71 Hz. -- Kenji Nakamura -- Massachusetts Institute of Technology "A soul is not exclusive to biology." From sreyes@cern.ch Thu Jan 19 21:26:25 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cern!sreyes From: sreyes@cern.ch (Sun-mi Reyes) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jan19.212625.4193@cern.ch> Date: Thu, 19 Jan 1995 21:26:25 GMT References: <1995Jan17.093725.3202@netcom.com> <1995Jan19.064925.5268@mit.edu> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Jan19.064925.5268@mit.edu>, knakamura@mit.edu (Kenji Nakamura) writes: > Prof. Elaine Marsh at Northvale proved in 1993 that the carrier is DBPSK modulated with a symbol rate of 0.71 Hz. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- === Sun-mi Reyes === Dept of Electrical Engineering, European Laboratory for Particle Physics, Geneva "Extraordinary claims require extraordinary spectra."