> > You can certainly start with a cheap no name card although > the noise floor will be somewhat higher (typically a 16 bit > motherboard sound system is at least 10x noiser than the > AP192, some have lots of spurs others are quieter). For a > long enough averaging time the system noise level even with a > cheap card will be somewhat lower than any OCXO you are > likely to have. > A cheap card will at least establish that in principle the > technique works. > You can then decide whether to upgrade it. > > The AP192 cards only have 2 input channels. > > Real AD cards with adequate performance are usually far more > expensive than $300. > In principle, one could build an ADC card with adequate > performance using 4 AD7760 ADCs. > > Bruce >
http://www.hpsdr.com/ Janus module is available built and PCB from TAPR (http://www.tapr.org/) Has a AKM AK5394 ADC on it, as well as a lower quality DAC. $163 assembled and tested. http://hpsdr.org/wiki/index.php?title=JANUS Claiming 120dB SNR, 20bit ENOB at 192ksps _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.