From tpark@berkeley.edu Mon Jul 04 04:18:19 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!berkeley!tpark From: tpark@berkeley.edu (Tomas Park) Newsgroups: comp.dsp Subject: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jul04.041819.3598@berkeley.edu> Date: Mon, 04 Jul 1994 04:18:19 GMT Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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. -- Tomas Park *PLONK* filter active for trolls. Pentium 90 (OS/2 Warp) - NetBSD 1.0 From ktanaka@inria.fr Mon Jul 04 13:00:19 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!inria!ktanaka From: ktanaka@inria.fr (Katrin Tanaka) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jul04.130019.2193@inria.fr> Date: Mon, 04 Jul 1994 13:00:19 GMT References: <1994Jul04.041819.3598@berkeley.edu> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Jul04.041819.3598@berkeley.edu>, tpark@berkeley.edu (Tomas Park) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). You're overlooking tape wow and flutter. A Revox B77 has at least 0.05% speed drift, which would smear a 14 Hz line across several bins. -- Katrin Tanaka SupraFAXModem 28.8 @ 28,800 bps "There are 14 nodes and only 10 countries. Count again." From lvasiliev@illinois.edu Tue Jul 05 19:31:19 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!illinois!lvasiliev From: lvasiliev@illinois.edu (Lars Vasiliev) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jul05.193119.3615@illinois.edu> Date: Tue, 05 Jul 1994 19:31:19 GMT References: <1994Jul04.041819.3598@berkeley.edu> <1994Jul04.130019.2193@inria.fr> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Jul04.130019.2193@inria.fr>, ktanaka@inria.fr (Katrin Tanaka) writes: > You're overlooking tape wow and flutter. A Revox B77 has at least 0.05% speed drift, which would smear a 14 Hz line across several bins. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Lars Vasiliev | lvasiliev@illinois.edu PGP Key fingerprint: 14E0 6BFC 594A 535D "Keep the channels open." From jjohansson@inria.fr Wed Jul 06 13:25:19 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!inria!jjohansson From: jjohansson@inria.fr (Ji-woo Johansson) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jul06.132519.2626@inria.fr> Date: Wed, 06 Jul 1994 13:25:19 GMT References: <1994Jul04.041819.3598@berkeley.edu> <1994Jul04.130019.2193@inria.fr> <1994Jul05.193119.3615@illinois.edu> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: Netscape 1.1N Lines: 8 In article <1994Jul05.193119.3615@illinois.edu>, lvasiliev@illinois.edu (Lars Vasiliev) writes: > Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. 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. -- Ji-woo Johansson Tape trading list upon request. SASE required for international mail.