Thanks, Bob! I was a little surprised when I started experimenting with the AD9834 to find all the spurs it produced, especially above one-quarter of the master clock frequency. When I figured out why the DDS generates spurs, I quickly came up with a way to nearly eliminate them. It's really the only thing about the LD-1 that's proprietary.
--- In [email protected], "g8voip" <g8voi.reeve...@...> wrote: > > Hi Kelvin, > > Just a trivial point. > > The Si570 is not actually a DDS device, uses a completely different method of > generating the final frequency. The net result is that the Si570 has a much > clearer output spectrum, and none of the spurs usually associated with DDS > chips, also the Si570 has lower phase noise. > > Although it does cost a little more, certainly worth it. > > It has has become the 'standard' oscillator source now for a number of > different SDR projects. > > 73, Bob G8VOI > > > --- In [email protected], "kcmuthumani" <kelvinm@> wrote: > > > > Hi Pete. > > > > This SDR looks very nice, before I order one do you have some specs on the > > unit ? I was wondering if you are going to post the schematics online. I > > could not find it on your web site. Also what DDS chip are you using Si570 > > ? or Analog Devices chip ? > > 73 > > Kelvin > > >
