[time-nuts] Microstepper

[Christophe Huygens]

Hello Anders,
I did the original design of the Crystek locked 1G CRO + 9912. Let me know if you have questions.
br
Christophe


________________________________
http://distrinet.cs.kuleuven.be/people/showMember.do?memberID=u0013167

prof. dr. ir. Christophe Huygens  IMEC-KULeuven-DistriNet

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From: time-nuts <time-nuts-bounces at lists.febo.com> on behalf of Anders Wallin <anders.e.e.wallin at gmail.com>
Sent: Tuesday, June 2, 2020 7:38 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Microstepper

There is now a first draft of the 'DDS-board', a 4-layer 100mm x 100mm PCB
with an ADF4351 PLL+VCO, and two AD9912 DDSs over here:
https://ohwr.org/project/microstepper/wikis/2020-06-02-DDSboard-draft
(kicad sources in the repository at
https://ohwr.org/project/microstepper/tree/master/ddsboard)

I will order a few prototype PCBs in a few weeks. In the meantime if anyone
has comments/suggests on the schematic or PCB from previous experience with
ADF4351, AD9912, or similar ICs then please let me know.
This DDS-board might be useful for other time/frequency tinkering also, in
addition to being a part of the second microstepper prototype I will try to
build within 1-3 months.

regards,
Anders

On Tue, Jan 14, 2020 at 8:58 AM Anders Wallin <anders.e.e.wallin at gmail.com>
wrote:

>
> 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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