From bgirard@uni-hamburg.de Tue Jun 28 15:58:26 1994 Path: ashpoly!cascade!mxgate!coyoacan!uni-hamburg!bgirard From: bgirard@uni-hamburg.de (Bastien Girard) Newsgroups: comp.dsp Subject: Question: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jun28.155826.7983@uni-hamburg.de> Date: Tue, 28 Jun 1994 15:58:26 GMT Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: TIN [version 1.2 PL2] Lines: 11 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. With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Bastien Girard | bgirard@uni-hamburg.de PGP Key fingerprint: 0C26 BEF4 4E4A 3FF1 "Keep the channels open." From sdubois@delphi.com Wed Jun 29 14:49:26 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!delphi!sdubois From: sdubois@delphi.com (Sun-mi Dubois) Newsgroups: comp.dsp Subject: Re: Question: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jun29.144926.3431@delphi.com> Date: Wed, 29 Jun 1994 14:49:26 GMT References: <1994Jun28.155826.7983@uni-hamburg.de> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1994Jun28.155826.7983@uni-hamburg.de>, bgirard@uni-hamburg.de (Bastien Girard) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. Top-posters will be placed in my ~/.killfile without notice. -- Sun-mi Dubois US Robotics Courier V.34 @ ISDN 64k bps "Extraordinary claims require extraordinary spectra." From nokonkwo@panix.com Fri Jul 01 14:40:26 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!panix!nokonkwo From: nokonkwo@panix.com (Nadia Okonkwo) Newsgroups: comp.dsp Subject: Re: Question: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jul01.144026.3682@panix.com> Date: Fri, 01 Jul 1994 14:40:26 GMT References: <1994Jun28.155826.7983@uni-hamburg.de> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Jun28.155826.7983@uni-hamburg.de>, bgirard@uni-hamburg.de (Bastien Girard) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Nadia Okonkwo -- Public Access Unix of New York "The hatch is open. Is anyone listening?" From jlarsson@mindspring.com Sun Jul 03 15:58:26 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!mindspring!jlarsson From: jlarsson@mindspring.com (Julien Larsson) Newsgroups: comp.dsp Subject: Re: Question: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jul03.155826.1052@mindspring.com> Date: Sun, 03 Jul 1994 15:58:26 GMT References: <1994Jun28.155826.7983@uni-hamburg.de> <1994Jun29.144926.3431@delphi.com> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Jun29.144926.3431@delphi.com>, sdubois@delphi.com (Sun-mi Dubois) 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. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Julien Larsson | jlarsson@mindspring.com PGP Key fingerprint: E77E F518 325E B235 "Keep the channels open."