From jtanaka@mindspring.com Sun Mar 24 01:49:44 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!mindspring!jtanaka From: jtanaka@mindspring.com (Ji-woo Tanaka) Newsgroups: comp.dsp Subject: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Mar24.014944.1528@mindspring.com> Date: Sun, 24 Mar 1996 01:49:44 GMT Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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. I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Ji-woo Tanaka Opinions expressed are solely my own and not those of MindSpring Enterprises. ------------------------------------------------------------ From lkarlsson@unam.mx Mon Mar 25 19:21:44 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!unam!lkarlsson From: lkarlsson@unam.mx (Liam Karlsson) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Mar25.192144.9413@unam.mx> Date: Mon, 25 Mar 1996 19:21:44 GMT References: <1996Mar24.014944.1528@mindspring.com> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Mar24.014944.1528@mindspring.com>, jtanaka@mindspring.com (Ji-woo Tanaka) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. Prof. Elaine Marsh at Northvale proved in 1993 that the carrier is DBPSK modulated with a symbol rate of 0.71 Hz. -- Liam Karlsson *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0 From bweber@delphi.com Tue Mar 26 05:19:44 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!delphi!bweber From: bweber@delphi.com (Bastien Weber) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Mar26.051944.5416@delphi.com> Date: Tue, 26 Mar 1996 05:19:44 GMT References: <1996Mar24.014944.1528@mindspring.com> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1996Mar24.014944.1528@mindspring.com>, jtanaka@mindspring.com (Ji-woo Tanaka) 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. -- Bastien Weber Tape trading list upon request. SASE required for international mail. From psmirnov@utexas.edu Wed Mar 27 03:10:44 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!utexas!psmirnov From: psmirnov@utexas.edu (Pavel Smirnov) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Mar27.031044.7239@utexas.edu> Date: Wed, 27 Mar 1996 03:10:44 GMT References: <1996Mar24.014944.1528@mindspring.com> <1996Mar26.051944.5416@delphi.com> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996Mar26.051944.5416@delphi.com>, bweber@delphi.com (Bastien Weber) writes: > 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. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Pavel Smirnov -- University of Texas at Austin "A soul is not exclusive to biology."