At 07:03 AM 8/25/2006, Jim Lux wrote: >Then, the I/Q audio signals run through separate channels, so there's a >"audio frequency" dependent variation between I and Q. This is fairly >fixed, independent of
DDS frequency (not audio frequency.. it varies a lot with audio frequency) >, but is also not particularly well >represented by a single phase/amplitude calibration value (as currently >used in PowerSDR), especially when used with wideband audio interfaces >(e.g. 96 kHz sampling, etc.). The audio interface manufacturers do a >fairly good job keeping phase and amplitude matched beween channels in the >middle ranges (say, 100 to 10 kHz), but not so wonderful farther out: their >primary criteria is making sure it "sounds right" and phase/amplitude >problems in the lower end of the range would result in "stereo imaging" >artifacts {Phase difference between L and R being one of the big cues for >how you tell what direction a sound is coming from}. Jim _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com