[time-nuts] Secondary phase noise standard & FE405

[Tim Shoppa]

Some AD DDS app notes give examples of spurs and choosing nearby (but not
exactly on freq) numbers that are much less bad for spurs - or at least
that move the spurs outside the cleanup filters/loops. I don't know of a
general example or even code that does this in a general way.

One paper I like on the subject is this:
http://ttcla.org/vsreinhardt/DDS%20spur%20reduction%20techniques.pdf

P.S. I just like saying "Wheatley Jitter Injector". Not for those who are
embarrassed easily... Almost as good as "Wankel Rotary Engine".

One of

On Sat, Nov 12, 2016 at 8:13 PM, Hal Murray <hmurray at megapathdsl.net> wrote:

>
> kb8tq at n1k.org said:
> > Yes, the FE-405 uses a DDS and a cleanup. Inside the cleanup loop the DDS
> > spurs come  straight through. Since the FE-405 compensates for all sorts
> of
> > things, the DDS moves around a lot. Even a one bit change on a DDS will
> move
> > spurs around. With an ever changing  DDS, you have an ever changing
> forest
> > of “stuff” on the output.
>
> Is there a web page or such telling me where the spurs will be on a DDS
> for a
> particular constant?
>
>
> --
> These are my opinions.  I hate spam.
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>