I like the AD9958/9959. Even with smaller D/A and accumulator, it has BETTER spur and noise floor than other models. A higher frequency clock (500 MHz) is required to get there but several companies make good ones.
http://www.analog.com/en/prod/0,2877,AD9958,00.html http://www.analog.com/en/prod/0,2877,AD9959,00.html Their ap engineers say these are improvements over the AD9951/9954 even though we they have smaller depth D/A's. The product notes seem to support this. The accumulator is smaller than the accumulator for the AD9854! 73's Bob N4HY KD5NWA wrote: > How clean that clock is extremely important, and a DDS source is not > very clean specially some 10 bit ones. > > You might want to do a little searching on Google, each different AD > DDS chips have their own pattern of frequencies where the spurs are > at a minimum. One of the things the SDR-1000 does to keep spurs down > is to move the clock to only clean frequencies. These frequencies can > be mathematically determined according to a formula so a simple > program or calculator can figure out your clean frequencies. > > -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman Laziness is the number one inspiration for ingenuity. Guilty as charged! Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/soft_radio/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
