[time-nuts] TAPR Oncore M12+ kit

[Bob kb8tq]

Hi


> On Apr 28, 2017, at 6:05 PM, Dave Mallery <dave.mallery at gmail.com> wrote:
> 
> hi
> 
> i posted much earlier.  status: the M12 works wonderfully with lady heather
> v5 from mark sims.  mine has completed its 48 hour precision survey and is
> purring along.
> 
> so far, i have had trouble with the serial to usb converter i picked up.
> the one on my other pi3/Tbolt rig runs fine.
> 
> can anyone speak to the issues involved in attaching an oscillator?

If by “attaching an oscillator” you mean building a GPSDO, the simple approach still is
to get a Lucent KS box on eBay and run it.  There is massive information in the archives
about them. For a bit more money, there are a number of alternatives.

To do a GPSDO well ( = at least as well as a KS box) there’s more than a little 
fiddling and hardware involved. It certainly can be done and people have done it. 
Even finding a decent oscillator is a challenge, getting it all together takes some time.

If by “attaching an oscillator” you simply want to calibrate an oscillator you already 
have … that’s different. The easy approach is to trigger one channel of your oscilloscope
on the pps out of the GPS. Run the oscillator output into the other input. If you have reason
to believe it’s > 1 Hz off, you will need to set it with a counter first. 

Once it is set up, the drift of the oscillator output left or right on the screen shows you
the degree to which the oscillator is high or low in frequency. With a reasonable 
scope and a few hours to watch things, you can get very close on your adjustment.

Lots of fun !!

Bob


> 
> thanks
> 
> dave mallery, k5en
> 
> On Fri, Apr 28, 2017 at 12:19 PM, Jerry Hancock <jerry at hanler.com> wrote:
> 
>> Is there a way I can help with this project?  If I had the specs to look
>> at, maybe I would be able to run off a bunch of plates.  If we could batch
>> them up I would do them for the cost of shipping.
>> 
>> Does anyone have a dimensioned print, picture, cad drawing of the plates?
>> 
>> 
>> 
>>> On Apr 28, 2017, at 11:33 AM, jimlux <jimlux at earthlink.net> wrote:
>>> 
>>> On 4/28/17 10:09 AM, Bob kb8tq wrote:
>>>> Hi
>>>> 
>>>> If you go with the PCB approach, the nice thing is getting stuff like
>>>> the slot for the D connector done at the PCB fab. That way you
>>>> have something that drops right in and works. The downside is that
>>>> not every pcb house is happy doing that sort of “CNC work”.  I
>>>> have absolutely no idea why. They all have to run some sort of gear
>>>> to cut the boards apart. Cutting slots or weird holes with it is pretty
>>>> trivial.
>>>> 
>>>> Bob
>>> 
>>> what about Front Panel Express?  They're in the whole business of small
>> run panels.  Not the cheapest place around, and you use their design tool,
>> but I've been happy with the quality of their work.
>>> 
>>> 
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> 
> 
> 
> -- 
> Dave Mallery, K5EN                 (ubuntu linux 16-10)
> PO Box 15                              Ophir,  OR  97464
> 
>      linux counter #64628 (since 1997)
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