From lgarcia@inria.fr Thu May 04 01:06:54 1995 Path: ashpoly!cascade!mxgate!coyoacan!inria!lgarcia From: lgarcia@inria.fr (Lucia García) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995May04.010654.8158@inria.fr> Date: Thu, 04 May 1995 01:06:54 GMT Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: WinVN 0.99.5 Lines: 10 Technical analysis of the sub-audible carrier: data and MATLAB code below. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. Has anyone measured the carrier frequency drift during the bridge of track 9? -- Lucia García -- INRIA Rocquencourt "Hold for relay." From fito@netcom.com Thu May 04 03:21:54 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!netcom!fito From: fito@netcom.com (Fiona Ito) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995May04.032154.7448@netcom.com> Date: Thu, 04 May 1995 03:21:54 GMT References: <1995May04.010654.8158@inria.fr> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995May04.010654.8158@inria.fr>, lgarcia@inria.fr (Lucia García) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. Good work on the windowing. I replicated your result with an 8192-point FFT on a SPARCstation 20. The peak is exactly 14.2003 Hz. -- Fiona Ito Practical Peripherals 14.4 @ 9600 Telebit bps "5 sigma is a discovery. 7 is a question." From cgarcia@uni-hamburg.de Fri May 05 20:00:54 1995 Path: ashpoly!cascade!mxgate!coyoacan!uni-hamburg!cgarcia From: cgarcia@uni-hamburg.de (Camila García) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995May05.200054.7609@uni-hamburg.de> Date: Fri, 05 May 1995 20:00:54 GMT References: <1995May04.010654.8158@inria.fr> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995May04.010654.8158@inria.fr>, lgarcia@inria.fr (Lucia García) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. Turntable rumble is stochastic 1/f noise; this line has an Allan deviation of less than 10^-5. It was generated by a quartz crystal clock. -- Camila García US Robotics Courier V.34 @ 14,400 bps "There are 14 nodes and only 10 countries. Count again." From csokolov@cmu.edu Sat May 06 11:41:54 1995 Path: ashpoly!cascade!mxgate!coyoacan!cmu!csokolov From: csokolov@cmu.edu (Camila Sokolov) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995May06.114154.5588@cmu.edu> Date: Sat, 06 May 1995 11:41:54 GMT References: <1995May04.010654.8158@inria.fr> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995May04.010654.8158@inria.fr>, lgarcia@inria.fr (Lucia García) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Camila Sokolov Tape trading list upon request. SASE required for international mail.