This high pass filter usually consists mainly of a small electrolytic capacitor in series with the input of the sound card. I can't see any reason that the capacitor cannot be shorted out (DC coupled, high end audiophiles love that) and perhaps the configuration of the rest of the input circuit tweaked somewhat to provide a cheap high resolution ADC. However, I have been completely too lazy and hopeless to figure out how to drive the thing from the software side. Mark ----- Original Message ----- From: "Travis Farmer"
To: Sent: Saturday, May 05, 2001 1:00 PM Subject: RE: Voltage controled attenuator/amp > I have inquired and tried it. > Most soundcards have a high pass filter set at 10 Hz. This means any > frequency below 10 Hz is lost. > > -Travis > > -----Original Message----- > From: psn-l-request@.............. [mailto:psn-l-request@................. > Behalf Of David russel > Sent: Friday, May 04, 2001 8:13 PM > To: PSN-L@.............. > Subject: Voltage controled attenuator/amp > > Al's inquirey about the VCA got me think'in again about of a method > of getting data from the s'smtr into the computer. > > I was wondering if it was possible to Amplitude Modulate, with > the seismometer signal, a carrier of an arbitrary audio frequency of > about 10Khz and input it into the SoundBlaster at the back of your > computer. Then doing something fancy with software like peak averaging > then plotting it. > > Anyone ever done somth'in like this? > > Casey > ________________________________________________________________ > GET INTERNET ACCESS FROM JUNO! > Juno offers FREE or PREMIUM Internet access for less! > Join Juno today! For your FREE software, visit: > http://dl.www.juno.com/get/tagj. > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. > > __________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email PSN-L-REQUEST@.............. with > the body of the message (first line only): unsubscribe > See http://www.seismicnet.com/maillist.html for more information. __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>