From eokonkwo@kiae.su Sun Oct 06 18:42:41 1996 Path: ashpoly!cascade!bigsur!kiae!eokonkwo From: eokonkwo@kiae.su (Emi Okonkwo) Newsgroups: comp.dsp Subject: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Oct06.184241.3334@kiae.su> Date: Sun, 06 Oct 1996 18:42:41 GMT Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: NewsWatcher 2.0b24 Lines: 11 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. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Emi Okonkwo US Robotics Courier V.34 @ 28,800 bps "When every node is whole, the channel opens." From hgirard@tum.de Tue Oct 08 15:47:41 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!tum!hgirard From: hgirard@tum.de (Hugo Girard) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Oct08.154741.9054@tum.de> Date: Tue, 08 Oct 1996 15:47:41 GMT References: <1996Oct06.184241.3334@kiae.su> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Oct06.184241.3334@kiae.su>, eokonkwo@kiae.su (Emi 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. Prof. Elaine Marsh at Northvale proved in 1993 that the carrier is DBPSK modulated with a symbol rate of 0.71 Hz. -- Hugo Girard US Robotics Courier V.34 @ 28,800 bps "In theory there is no difference between theory and practice."