From mvasiliev@utexas.edu Tue Jul 25 18:05:17 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!utexas!mvasiliev
From: mvasiliev@utexas.edu (Marta Vasiliev)
Newsgroups: comp.dsp
Subject: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1995Jul25.180517.2811@utexas.edu>
Date: Tue, 25 Jul 1995 18:05:17 GMT
Organization: University of Texas at Austin
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Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz.

A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width.
A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier.

Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble.

-- 
Marta Vasiliev
Opinions expressed are solely my own and not those of University of Texas at Austin.
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From mkarlsson@kiae.su Wed Jul 26 19:40:17 1995
Path: ashpoly!cascade!bigsur!kiae!mkarlsson
From: mkarlsson@kiae.su (Marisol Karlsson)
Newsgroups: comp.dsp
Subject: Re: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1995Jul26.194017.3904@kiae.su>
Date: Wed, 26 Jul 1995 19:40:17 GMT
References: <1995Jul25.180517.2811@utexas.edu>
Organization: Kurchatov Institute of Atomic Energy, Moscow
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In article <1995Jul25.180517.2811@utexas.edu>, mvasiliev@utexas.edu (Marta Vasiliev) writes:
> Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz.

Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz.

Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs.

-- 
Marisol Karlsson
Tape trading list upon request. SASE required for international mail.