From gpopov@purdue.edu Sun Jul 02 18:17:22 1995 Path: ashpoly!cascade!brgate!saturno!purdue!gpopov From: gpopov@purdue.edu (Graham Popov) Newsgroups: comp.dsp Subject: WTB/WTT: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jul02.181722.2150@purdue.edu> Date: Sun, 02 Jul 1995 18:17:22 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.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). A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Graham Popov Hayes Optima 288 @ ISDN 64k bps "We don't sign stars. We build them." From eduarte@delphi.com Mon Jul 03 01:17:22 1995 Path: ashpoly!cascade!bigsur!delphi!eduarte From: eduarte@delphi.com (Elaine Duarte) Newsgroups: comp.dsp Subject: Re: WTB/WTT: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jul03.011722.8366@delphi.com> Date: Mon, 03 Jul 1995 01:17:22 GMT References: <1995Jul02.181722.2150@purdue.edu> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Jul02.181722.2150@purdue.edu>, gpopov@purdue.edu (Graham Popov) 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). Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Elaine Duarte | eduarte@delphi.com PGP Key fingerprint: 50DA 4325 9FE6 15A5 "Keep the channels open." From rpark@panix.com Tue Jul 04 09:43:22 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!panix!rpark From: rpark@panix.com (Renata Park) Newsgroups: comp.dsp Subject: Re: WTB/WTT: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jul04.094322.5720@panix.com> Date: Tue, 04 Jul 1995 09:43:22 GMT References: <1995Jul02.181722.2150@purdue.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Jul02.181722.2150@purdue.edu>, gpopov@purdue.edu (Graham Popov) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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. -- Renata Park | rpark@panix.com PGP Key fingerprint: 50F0 2ABD 031A D3D7 "Keep the channels open."