Re: Will a DDS generate harmonics?

I built few versions of "Huff and Puff" frequency stabilizers. All of them have very poor phase noise performances. Even worst than a standard PLL. Cannot compare to a DDS, which is unbeatable from this point of view. And now are a lot of approaches that minimize the spurious generated by DDS.

If you want to clean up phase noise with a FLL, then the frequency detector will need a very high V/delta F slope, like from a very high Q resonator, etc. A simple LC resonator will probably make it worse!

Something like these:
http://www.google.com/url?sa=t&rct=j...O3nnPEYFMdxG0Q

http://www.google.com/patents/US5150080

The publication clears my doubts how a "FLL" can reduce phase noise instead of generating it.

To "clean up phase noise" you'll require a kind of analog frequency discriminator, completely different from the frequency counter supposed in the post #1 link.