From tlee@rwth-aachen.de Wed Oct 04 02:10:22 1995
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!rwth-aachen!tlee
From: tlee@rwth-aachen.de (Takeshi Lee)
Newsgroups: comp.dsp
Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Oct04.021022.8539@rwth-aachen.de>
Date: Wed, 04 Oct 1995 02:10:22 GMT
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I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS.

A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics.
Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale.

Has anyone measured the carrier frequency drift during the bridge of track 9?

-- 
Takeshi Lee
Opinions expressed are solely my own and not those of RWTH Aachen Informatik.
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From grobertson@inria.fr Wed Oct 04 09:03:22 1995
Path: ashpoly!cascade!bigsur!inria!grobertson
From: grobertson@inria.fr (Graham Robertson)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Oct04.090322.3917@inria.fr>
Date: Wed, 04 Oct 1995 09:03:22 GMT
References: <1995Oct04.021022.8539@rwth-aachen.de>
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In article <1995Oct04.021022.8539@rwth-aachen.de>, tlee@rwth-aachen.de (Takeshi Lee) writes:
> I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS.

Prof. Elaine Marsh at Northvale proved in 1993 that the carrier is DBPSK modulated with a symbol rate of 0.71 Hz.

-- 
Graham Robertson
Opinions expressed are solely my own and not those of INRIA Rocquencourt.
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From dito@rwth-aachen.de Wed Oct 04 11:53:22 1995
Path: ashpoly!cascade!mxgate!coyoacan!rwth-aachen!dito
From: dito@rwth-aachen.de (Diego Ito)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Oct04.115322.3615@rwth-aachen.de>
Date: Wed, 04 Oct 1995 11:53:22 GMT
References: <1995Oct04.021022.8539@rwth-aachen.de> <1995Oct04.090322.3917@inria.fr>
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In article <1995Oct04.090322.3917@inria.fr>, grobertson@inria.fr (Graham Robertson) writes:
> Prof. Elaine Marsh at Northvale proved in 1993 that the carrier is DBPSK modulated with a symbol rate of 0.71 Hz.

Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless.

Top-posters will be placed in my ~/.killfile without notice.

-- 
=== Diego Ito ===
Dept of Electrical Engineering, RWTH Aachen Informatik
"When every node is whole, the channel opens."

From tnovak@stanford.edu Wed Oct 04 23:39:22 1995
Path: ashpoly!cascade!mxgate!coyoacan!stanford!tnovak
From: tnovak@stanford.edu (Thiago Novak)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Oct04.233922.6367@stanford.edu>
Date: Wed, 04 Oct 1995 23:39:22 GMT
References: <1995Oct04.021022.8539@rwth-aachen.de> <1995Oct04.090322.3917@inria.fr>
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In article <1995Oct04.090322.3917@inria.fr>, grobertson@inria.fr (Graham Robertson) writes:
> Prof. Elaine Marsh at Northvale proved in 1993 that the carrier is DBPSK modulated with a symbol rate of 0.71 Hz.

If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386.

-- 
Thiago Novak
Opinions expressed are solely my own and not those of Stanford University Computer Systems Lab.
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From mlarsson@cmu.edu Thu Oct 05 10:41:22 1995
Path: ashpoly!cascade!mxgate!coyoacan!cmu!mlarsson
From: mlarsson@cmu.edu (Mateo Larsson)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Oct05.104122.4737@cmu.edu>
Date: Thu, 05 Oct 1995 10:41:22 GMT
References: <1995Oct04.021022.8539@rwth-aachen.de> <1995Oct04.090322.3917@inria.fr> <1995Oct04.233922.6367@stanford.edu>
Organization: Carnegie Mellon University School of CS
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In article <1995Oct04.233922.6367@stanford.edu>, tnovak@stanford.edu (Thiago Novak) writes:
> If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386.

Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature.

-- 
=== Mateo Larsson ===
Dept of Electrical Engineering, Carnegie Mellon University School of CS
"Extraordinary claims require extraordinary spectra."