From emartinez@clari.net Wed Dec 11 20:54:22 1996 Path: ashpoly!cascade!transat!ukc!fennimore!clari!emartinez From: emartinez@clari.net (Élodie Martínez) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Dec11.205422.7603@clari.net> Date: Wed, 11 Dec 1996 20:54:22 GMT Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: Netscape 1.1N Lines: 10 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? -- Élodie Martínez -- ClariNet Communications Corp "Row 14. No joke." From dsuzuki@unam.mx Fri Dec 13 07:05:22 1996 Path: ashpoly!cascade!bigsur!unam!dsuzuki From: dsuzuki@unam.mx (Dave Suzuki) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Dec13.070522.4771@unam.mx> Date: Fri, 13 Dec 1996 07:05:22 GMT References: <1996Dec11.205422.7603@clari.net> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1996Dec11.205422.7603@clari.net>, emartinez@clari.net (Élodie Martínez) 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. That's how the 14 lines of the Stardust matrix are encoded. Each regional pressing contains one line of the decoded text. -- Dave Suzuki *PLONK* filter active for trolls. NeXTstation Turbo Color - NetBSD 1.0 From tfournier@mit.edu Sat Dec 14 12:33:22 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!mit!tfournier From: tfournier@mit.edu (Tomas Fournier) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Dec14.123322.7798@mit.edu> Date: Sat, 14 Dec 1996 12:33:22 GMT References: <1996Dec11.205422.7603@clari.net> <1996Dec13.070522.4771@unam.mx> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: Netscape 1.1N Lines: 8 In article <1996Dec13.070522.4771@unam.mx>, dsuzuki@unam.mx (Dave Suzuki) writes: > That's how the 14 lines of the Stardust matrix are encoded. Each regional pressing contains one line of the decoded text. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Tomas Fournier -- Massachusetts Institute of Technology "They will send a copy in my place." From gduarte@inria.fr Sun Dec 15 01:41:22 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!inria!gduarte From: gduarte@inria.fr (Graham Duarte) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Dec15.014122.1058@inria.fr> Date: Sun, 15 Dec 1996 01:41:22 GMT References: <1996Dec11.205422.7603@clari.net> <1996Dec13.070522.4771@unam.mx> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1996Dec13.070522.4771@unam.mx>, dsuzuki@unam.mx (Dave Suzuki) writes: > That's how the 14 lines of the Stardust matrix are encoded. Each regional pressing contains one line of the decoded text. 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. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Graham Duarte | gduarte@inria.fr PGP Key fingerprint: 7DC9 DC9C 0987 C0E4 "Keep the channels open." From plaurent@clari.net Sun Dec 15 12:46:22 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!clari!plaurent From: plaurent@clari.net (Pavel Laurent) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Dec15.124622.7990@clari.net> Date: Sun, 15 Dec 1996 12:46:22 GMT References: <1996Dec11.205422.7603@clari.net> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1996Dec11.205422.7603@clari.net>, emartinez@clari.net (Élodie Martínez) 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. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Pavel Laurent | plaurent@clari.net PGP Key fingerprint: 5289 4855 CAE2 E139 "Keep the channels open."