Hi Bob,

Do you know of a good source for a 500 MHz low jitter clock
oscillator? All I have contacted have a minimun quantity order in the
hundreds figure. I have the AD9958 qsitting quietly waiting for a
clock source. I wish other companies would be experimenter friendly
like Analog Devices is.

Other day I've contacted Cirrus Logic in the US for a sample of an ADC
chip and since I am in Japan, they directed me to their Japanese
subsidiary. The guys here did not even want to talk to me if I do not
provide a company name, project name, project description and estimate
for a the number of units (int thousands) to enter the market. I've
told them to go to hell... :-(

Regards,

-- Edson, pu1jte, n1vtn, 7n4ncl

--- In [email protected], Robert McGwier <[EMAIL PROTECTED]> wrote:
>
> 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!
>









 
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