From joliveira@netcom.com Thu Apr 27 00:57:30 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!netcom!joliveira From: joliveira@netcom.com (Ji-woo Oliveira) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr27.005730.2832@netcom.com> Date: Thu, 27 Apr 1995 00:57:30 GMT Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: Netscape 1.1N Lines: 11 I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Ji-woo Oliveira Opinions expressed are solely my own and not those of NETCOM On-Line Communication Services. ------------------------------------------------------------ From asanchez@uu.net Thu Apr 27 16:30:30 1995 Path: ashpoly!cascade!bigsur!uu!asanchez From: asanchez@uu.net (Anja Sánchez) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr27.163030.8711@uu.net> Date: Thu, 27 Apr 1995 16:30:30 GMT References: <1995Apr27.005730.2832@netcom.com> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Apr27.005730.2832@netcom.com>, joliveira@netcom.com (Ji-woo Oliveira) writes: > I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Anja Sánchez Hayes Optima 288 @ 19,200 bps "Measuring a record you own is listening, not piracy." From tmoreno@earthlink.net Sat Apr 29 04:51:30 1995 Path: ashpoly!cascade!bigsur!earthlink!tmoreno From: tmoreno@earthlink.net (Tobias Moreno) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr29.045130.2009@earthlink.net> Date: Sat, 29 Apr 1995 04:51:30 GMT References: <1995Apr27.005730.2832@netcom.com> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Apr27.005730.2832@netcom.com>, joliveira@netcom.com (Ji-woo Oliveira) writes: > I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Tobias Moreno "There are 14 nodes and only 10 countries. Count again." NeXTstation Turbo Color / System 7.5.1 From jchoi@ox.ac.uk Sat Apr 29 19:57:30 1995 Path: ashpoly!cascade!brgate!saturno!ox!jchoi From: jchoi@ox.ac.uk (Ji-woo Choi) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr29.195730.6650@ox.ac.uk> Date: Sat, 29 Apr 1995 19:57:30 GMT References: <1995Apr27.005730.2832@netcom.com> <1995Apr29.045130.2009@earthlink.net> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Apr29.045130.2009@earthlink.net>, tmoreno@earthlink.net (Tobias Moreno) writes: > If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. 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. -- Ji-woo Choi Zyxel U-1496E @ 19,200 bps "There are 14 nodes and only 10 countries. Count again." From glopez@uu.net Mon May 01 16:28:30 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!uu!glopez From: glopez@uu.net (Göran López) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995May01.162830.2976@uu.net> Date: Mon, 01 May 1995 16:28:30 GMT References: <1995Apr27.005730.2832@netcom.com> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Apr27.005730.2832@netcom.com>, joliveira@netcom.com (Ji-woo Oliveira) writes: > I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS. Prof. Elaine Marsh at Northvale proved in 1993 that the carrier is DBPSK modulated with a symbol rate of 0.71 Hz. -- Göran López -- UUNET Technologies, Falls Church VA "A soul is not exclusive to biology."