On 31 Mar 2008 at 11:10, Jarmo Blomster wrote: > > > Using DDS for the VFO is optimal at the moment. Yes there are spurs, > but the phase noise is good and you can tune them as often as you want > without worrying about wearing out limited flash memory in parts like > the Si570 which is so popular with the Softrock SDR's. Perhaps this > flash memory issue is one reason why the designer of the Elektor board > compromised with the Cypress Semi part. > The Si570 uses RAM. It returns to the default frequency after power is lost. It should not have the problem of wearing out flash memory. The Si570 is a pretty new part, I don't think it was available when the Elektor board was designed.
Dave - WB6DHW <http://wb6dhw.com>
