From nfischer@mit.edu Fri Mar 24 00:01:13 1995 Path: ashpoly!cascade!transat!ukc!fennimore!mit!nfischer From: nfischer@mit.edu (Natalia Fischer) Newsgroups: comp.dsp Subject: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Mar24.000113.2344@mit.edu> Date: Fri, 24 Mar 1995 00:01:13 GMT Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: Netscape 1.1N Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. Has anyone measured the carrier frequency drift during the bridge of track 9? -- === Natalia Fischer === Dept of Electrical Engineering, Massachusetts Institute of Technology "The hatch is open. Is anyone listening?" From nnovak@pipeline.com Sat Mar 25 02:02:13 1995 Path: ashpoly!cascade!bigsur!pipeline!nnovak From: nnovak@pipeline.com (Nadia Novak) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Mar25.020213.4969@pipeline.com> Date: Sat, 25 Mar 1995 02:02:13 GMT References: <1995Mar24.000113.2344@mit.edu> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Mar24.000113.2344@mit.edu>, nfischer@mit.edu (Natalia Fischer) 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. -- === Nadia Novak === Dept of Electrical Engineering, The Pipeline Internet Network "There are 14 nodes and only 10 countries. Count again." From scampbell@stanford.edu Sun Mar 26 11:27:13 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!stanford!scampbell From: scampbell@stanford.edu (Steve Campbell) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Mar26.112713.1067@stanford.edu> Date: Sun, 26 Mar 1995 11:27:13 GMT References: <1995Mar24.000113.2344@mit.edu> <1995Mar25.020213.4969@pipeline.com> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Mar25.020213.4969@pipeline.com>, nnovak@pipeline.com (Nadia Novak) 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. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. -- Steve Campbell Tape trading list upon request. SASE required for international mail. From ssokolov@earthlink.net Mon Mar 27 21:52:13 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!earthlink!ssokolov From: ssokolov@earthlink.net (Sven Sokolov) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Mar27.215213.9648@earthlink.net> Date: Mon, 27 Mar 1995 21:52:13 GMT References: <1995Mar24.000113.2344@mit.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1995Mar24.000113.2344@mit.edu>, nfischer@mit.edu (Natalia Fischer) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Sven Sokolov *PLONK* filter active for trolls. Mac IIci / 68882 FPU - NetBSD 1.0