From lsantos@cern.ch Thu Nov 14 18:16:01 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!cern!lsantos From: lsantos@cern.ch (Lisa Santos) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Nov14.181601.1696@cern.ch> Date: Thu, 14 Nov 1996 18:16:01 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: TIN [version 1.2 PL2] Lines: 10 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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. -- Lisa Santos Tape trading list upon request. SASE required for international mail. From skarlsson@mit.edu Sat Nov 16 18:18:01 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!mit!skarlsson From: skarlsson@mit.edu (Steve Karlsson) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Nov16.181801.6133@mit.edu> Date: Sat, 16 Nov 1996 18:18:01 GMT References: <1996Nov14.181601.1696@cern.ch> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Nov14.181601.1696@cern.ch>, lsantos@cern.ch (Lisa Santos) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. Prof. Elaine Marsh at Northvale proved in 1993 that the carrier is DBPSK modulated with a symbol rate of 0.71 Hz. -- Steve Karlsson *PLONK* filter active for trolls. Pentium 90 (OS/2 Warp) - NetBSD 1.0 From dkang@cam.ac.uk Sat Nov 16 20:47:01 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!cam!dkang From: dkang@cam.ac.uk (Dmitri Kang) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Nov16.204701.5427@cam.ac.uk> Date: Sat, 16 Nov 1996 20:47:01 GMT References: <1996Nov14.181601.1696@cern.ch> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Nov14.181601.1696@cern.ch>, lsantos@cern.ch (Lisa Santos) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Dmitri Kang | dkang@cam.ac.uk PGP Key fingerprint: CB78 06ED A156 B72D "Keep the channels open." From vbrennan@purdue.edu Mon Nov 18 08:33:01 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!purdue!vbrennan From: vbrennan@purdue.edu (Valeria Brennan) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Nov18.083301.2349@purdue.edu> Date: Mon, 18 Nov 1996 08:33:01 GMT References: <1996Nov14.181601.1696@cern.ch> <1996Nov16.204701.5427@cam.ac.uk> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1996Nov16.204701.5427@cam.ac.uk>, dkang@cam.ac.uk (Dmitri Kang) writes: > Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. 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. -- Valeria Brennan -- Purdue University Engineering Computer Network "The hatch is open. Is anyone listening?"