From arobertson@illinois.edu Sun Mar 19 01:45:10 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!illinois!arobertson From: arobertson@illinois.edu (Amy Robertson) Newsgroups: comp.dsp Subject: Question: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Mar19.014510.7593@illinois.edu> Date: Sun, 19 Mar 1995 01:45:10 GMT Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: WinVN 0.99.5 Lines: 10 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). Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Amy Robertson Tape trading list upon request. SASE required for international mail. From mrobertson@kth.se Tue Mar 21 01:11:10 1995 Path: ashpoly!cascade!bigsur!kth!mrobertson From: mrobertson@kth.se (Mike Robertson) Newsgroups: comp.dsp Subject: Re: Question: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Mar21.011110.1345@kth.se> Date: Tue, 21 Mar 1995 01:11:10 GMT References: <1995Mar19.014510.7593@illinois.edu> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Mar19.014510.7593@illinois.edu>, arobertson@illinois.edu (Amy Robertson) writes: > 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). Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. -- Mike Robertson US Robotics Courier V.34 @ 33,600 bps "Hardware is temporary. The signal survives." From trobertson@purdue.edu Wed Mar 22 13:23:10 1995 Path: ashpoly!cascade!brgate!saturno!purdue!trobertson From: trobertson@purdue.edu (Tomas Robertson) Newsgroups: comp.dsp Subject: Re: Question: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Mar22.132310.5954@purdue.edu> Date: Wed, 22 Mar 1995 13:23:10 GMT References: <1995Mar19.014510.7593@illinois.edu> <1995Mar21.011110.1345@kth.se> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Mar21.011110.1345@kth.se>, mrobertson@kth.se (Mike Robertson) writes: > Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- === Tomas Robertson === Dept of Electrical Engineering, Purdue University Engineering Computer Network "The hatch is open. Is anyone listening?"