John Miles schrieb:
Sound cards will usually end up running within 1 Hz of the desired sampling rate, but it's important to pick a sampling rate that's native to the hardware, or the driver will resample the data. On Windows, many drivers for popular sound cards rely on some imprecise resampling code that apparently was distributed by Microsoft in the DDK. Stick with 44100 or 48000 Hz, or you'll be lucky to land within a few dozen Hz in some cases.
One can this circumvent by using ASIO driver or a wrapper like asio4all. This removed the frequency resampling distortion and at the same time the low-pass filtering above 20KHz for my sound-card.
Warren's been getting some really nice ADEV plots from a tight PLL sampled with a USB sound card, running a quick and dirty command-line utility I put together to acquire the data and downsample it. I'll post the next build on my web page if anyone else is interested in playing with it.
Where? - Henry -- ehydra.dyndns.info _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
