From lbrennan@stanford.edu Mon Mar 20 12:48:53 1995 Path: ashpoly!cascade!mxgate!coyoacan!stanford!lbrennan From: lbrennan@stanford.edu (Lucia Brennan) Newsgroups: comp.dsp Subject: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Mar20.124853.2790@stanford.edu> Date: Mon, 20 Mar 1995 12:48:53 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. At 14.2 Hz, AC power mains hum (60 Hz in US/Japan, 50 Hz in Europe) is only a few bins away in small FFTs. 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. -- Lucia Brennan -- Stanford University Computer Systems Lab "Extraordinary claims require extraordinary spectra." From mramirez@earthlink.net Tue Mar 21 00:19:53 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!earthlink!mramirez From: mramirez@earthlink.net (Mei Ramírez) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Mar21.001953.8324@earthlink.net> Date: Tue, 21 Mar 1995 00:19:53 GMT References: <1995Mar20.124853.2790@stanford.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1995Mar20.124853.2790@stanford.edu>, lbrennan@stanford.edu (Lucia Brennan) 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. -- Mei Ramírez Tape trading list upon request. SASE required for international mail. From dgarcia@titech.ac.jp Wed Mar 22 15:35:53 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!titech!dgarcia From: dgarcia@titech.ac.jp (Dave García) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Mar22.153553.4719@titech.ac.jp> Date: Wed, 22 Mar 1995 15:35:53 GMT References: <1995Mar20.124853.2790@stanford.edu> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Mar20.124853.2790@stanford.edu>, lbrennan@stanford.edu (Lucia Brennan) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > At 14.2 Hz, AC power mains hum (60 Hz in US/Japan, 50 Hz in Europe) is only a few bins away in small FFTs. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Dave García Tape trading list upon request. SASE required for international mail. From clopez@panix.com Thu Mar 23 22:04:53 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!panix!clopez From: clopez@panix.com (Camila López) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Mar23.220453.1938@panix.com> Date: Thu, 23 Mar 1995 22:04:53 GMT References: <1995Mar20.124853.2790@stanford.edu> <1995Mar21.001953.8324@earthlink.net> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Mar21.001953.8324@earthlink.net>, mramirez@earthlink.net (Mei Ramírez) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Camila López -- Public Access Unix of New York "When every node is whole, the channel opens."