[time-nuts] Microstepper

[Anders Wallin]

prototype block-diagram, short list of chips in the implementation, and a
discussion on resolution now on ohwr.org:
https://ohwr.org/project/microstepper/wikis/Block-diagram

The obvious way to increase resolution (make the smallest frequency step
smaller) is to lower the IF.
I guess the limit is that we don't want the IF to feed-thru the
phase-detector and PLL all the way to a PN-spur in the output-OCXO.
My first prototype used 97 kHz IF and that gives a resolution of 1.7e-17.
Lowering that by /2 or /4 might be a good idea?
Other comments and ideas welcome!

Anders


> my plan is to present our DIY version of this, an open hardware design, at
> EFTF2020.
> we have two AD9912:s clocked at 1GHz (derived from the maser) producing
> two LO's that drive a mixer-board that locks an OCXO that feeds a PICDIV.
>
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