Poul-Henning Kamp said: > That's one of the reason I went with Bo's DDS (32bit0 instead of the eBay > modules (20-24 bit). Higher resolution mitigates the spur problem at least a > little bit.
I think it also moves the spurs closer in. But maybe if they are small enough they get lost in the normal noise. Does anybody have a handy formula for the spurs given the parameters for a DDS? I've occasionally thought of writing code to generate the output of a DDS and run it through a FFT. I haven't figured out how much memory that would need, or rather how wide a DDS I could simulate with the memory I have. A 20 bit accumulator repeats after a million cycles. At 8 bytes/sample that's 8 megabytes which I can do. (Round down if FFT needs another copy.) We are only interested in the close-in area, so old brute-force calculations maybe fast enough. -- These are my opinions. I hate spam. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://lists.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
