You are thinking analog world, for a FET switch based QSD detector square waves with sharp edges are the best thing in the world.
A DDS is a wonderful device if you understand it limits, it's ability to have a incredibly huge range of frequencies, and make changes instantaneously is great, but you have to deal with spurs it generates. AD is learning and the new generation of AD99XX DDS chips are way cleaner that the AD98XX series. A PLL is cleaner far out, but not as clean close in, and for some uses it's not usable if it requires quick changes in frequency. One of these days I want to try a PLL for the clock using a really clean 600MHz to 800MHz VCO and a PLL chip by national, with the clean clock and the dividing you need to get down to the HF region it should be very clean and free of spurs, but it will not be cheap. At 01:15 PM 4/15/2006, you wrote: >n3hkn: > > I am glad you are explaining these details on the spurious output > of the DDS clock circuit. I have a diagram of the V5 and can think > of it in my head. My original question on the clock circuit square > wave forms led me to inquire about spurs earlier on since I know > that square waves are notorious for that unless you can filter them > out into sine waves with some coils and caps. > >Dan > > >_____________________________________________________________________ >Call Anyone, Anytime, Anywhere in the World - FREE! >Free Internet calling from NetZero Voice >Visit http://www.netzerovoice.com today! > > > > > >Yahoo! Groups Links > > > > Cecil Bayona KD5NWA www.qrpradio.com "Windows the worlds most successful software virus" 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/
