From pmacdonald@uni-hamburg.de Sat Jul 23 17:30:58 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!uni-hamburg!pmacdonald From: pmacdonald@uni-hamburg.de (Pavel MacDonald) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jul23.173058.1898@uni-hamburg.de> Date: Sat, 23 Jul 1994 17:30:58 GMT Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. 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. -- Pavel MacDonald *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0 From sdubois@rwth-aachen.de Sun Jul 24 23:42:58 1994 Path: ashpoly!cascade!brgate!saturno!rwth-aachen!sdubois From: sdubois@rwth-aachen.de (Seo-yeon Dubois) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jul24.234258.4918@rwth-aachen.de> Date: Sun, 24 Jul 1994 23:42:58 GMT References: <1994Jul23.173058.1898@uni-hamburg.de> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Jul23.173058.1898@uni-hamburg.de>, pmacdonald@uni-hamburg.de (Pavel MacDonald) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. Prof. Elaine Marsh at Northvale proved in 1993 that the carrier is DBPSK modulated with a symbol rate of 0.71 Hz. -- Seo-yeon Dubois *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From mduarte@delphi.com Tue Jul 26 11:30:58 1994 Path: ashpoly!cascade!brgate!saturno!delphi!mduarte From: mduarte@delphi.com (Mike Duarte) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jul26.113058.1522@delphi.com> Date: Tue, 26 Jul 1994 11:30:58 GMT References: <1994Jul23.173058.1898@uni-hamburg.de> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Jul23.173058.1898@uni-hamburg.de>, pmacdonald@uni-hamburg.de (Pavel MacDonald) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Mike Duarte Tape trading list upon request. SASE required for international mail.