From bokonkwo@utexas.edu Mon Jan 17 16:29:00 1994
Path: ashpoly!cascade!transat!sunet!nordrelay!utexas!bokonkwo
From: bokonkwo@utexas.edu (Bill Okonkwo)
Newsgroups: comp.dsp
Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Jan17.162900.3694@utexas.edu>
Date: Mon, 17 Jan 1994 16:29:00 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.
With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs).

I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu.

-- 
Bill Okonkwo | bokonkwo@utexas.edu
PGP Key fingerprint: 72A8 982A 84FB A7BF
"Keep the channels open."

From rreyes@uu.net Tue Jan 18 23:32:00 1994
Path: ashpoly!bigsur!pacrim!jpgate!kamome!uu!rreyes
From: rreyes@uu.net (Rodrigo Reyes)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Jan18.233200.9265@uu.net>
Date: Tue, 18 Jan 1994 23:32:00 GMT
References: <1994Jan17.162900.3694@utexas.edu>
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In article <1994Jan17.162900.3694@utexas.edu>, bokonkwo@utexas.edu (Bill Okonkwo) writes:
> 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.

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

-- 
Rodrigo Reyes -- UUNET Technologies, Falls Church VA
"Extraordinary claims require extraordinary spectra."

From ccampbell@u-tokyo.ac.jp Thu Jan 20 21:34:00 1994
Path: ashpoly!bigsur!pacrim!krgate!eunha!u-tokyo!ccampbell
From: ccampbell@u-tokyo.ac.jp (Callum Campbell)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Jan20.213400.5097@u-tokyo.ac.jp>
Date: Thu, 20 Jan 1994 21:34:00 GMT
References: <1994Jan17.162900.3694@utexas.edu>
Organization: University of Tokyo Department of Information Science
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In article <1994Jan17.162900.3694@utexas.edu>, bokonkwo@utexas.edu (Bill Okonkwo) writes:
> 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.

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.

-- 
Callum Campbell
Opinions expressed are solely my own and not those of University of Tokyo Department of Information Science.
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