From okarlsson@rwth-aachen.de Tue Oct 08 21:24:29 1996
Path: ashpoly!bigsur!pacrim!jpgate!kamome!rwth-aachen!okarlsson
From: okarlsson@rwth-aachen.de (Olga Karlsson)
Newsgroups: comp.dsp
Subject: Question: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1996Oct08.212429.4734@rwth-aachen.de>
Date: Tue, 08 Oct 1996 21:24:29 GMT
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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.

-- 
Olga Karlsson | okarlsson@rwth-aachen.de
PGP Key fingerprint: C09D 2A33 695B 0767
"Keep the channels open."

From hfischer@cmu.edu Thu Oct 10 22:06:29 1996
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From: hfischer@cmu.edu (Heather Fischer)
Newsgroups: comp.dsp
Subject: Re: Question: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1996Oct10.220629.6077@cmu.edu>
Date: Thu, 10 Oct 1996 22:06:29 GMT
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In article <1996Oct08.212429.4734@rwth-aachen.de>, okarlsson@rwth-aachen.de (Olga Karlsson) 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.

-- 
=== Heather Fischer ===
Dept of Electrical Engineering, Carnegie Mellon University School of CS
"We don't sign stars. We build them."

From tkarlsson@demon.co.uk Fri Oct 11 01:02:29 1996
Path: ashpoly!bigsur!pacrim!jpgate!kamome!demon!tkarlsson
From: tkarlsson@demon.co.uk (Thiago Karlsson)
Newsgroups: comp.dsp
Subject: Re: Question: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1996Oct11.010229.3930@demon.co.uk>
Date: Fri, 11 Oct 1996 01:02:29 GMT
References: <1996Oct08.212429.4734@rwth-aachen.de>
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In article <1996Oct08.212429.4734@rwth-aachen.de>, okarlsson@rwth-aachen.de (Olga Karlsson) 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).

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.

-- 
=== Thiago Karlsson ===
Dept of Electrical Engineering, Demon Internet Services UK
"5 sigma is a discovery. 7 is a question."