[time-nuts] RFX GPSDO - Anybody played with one of these?

[Jim Lux]

On 10/2/12 10:35 PM, bg at lysator.liu.se wrote:
>> On 10/2/12 2:36 PM, SAIDJACK at aol.com wrote:
>>> Hello Paul,
>>>
>>> thanks much for the feedback!
>>>
>>> Yes, we think we have identified a nice combination of oscillators, GPS,
>>> and firmware that seems to work pretty well. The GPSTCXO units cannot be
>>> compared to a lower cost $150 Thunderbolt in terms of phase noise or
>>> stability
>>> of course, and they have CMOS 10MHz outputs, but then the  TB's cost
>>> around
>>> $1500 new I guess.
>>>
>>> We think the GPSTCXO's and LC_XO type units will work quite well
>>> wherever
>>> standard OCXO's are used today, and power/size/weight are an  issue.
>>>
>>
>>
>> Intriguing.. Can it handle the Doppler, etc., for a cubesat in LEO?
>> (7km/s)  The total Doppler isn't usually the issue (the GPS satellites
>> are moving faster, after all), but the receiver may not work for high
>> velocities, high altitudes?
>
> GPS SVs moves at around 4km/s, but nevertheless there are still COCOM
> limits implemented in nearly all receivers (never break both 504m/s and
> 18km height)
>

Doh. of course. higher is slower


In any case, though, nothing stops Jackson Labs from selling one that is 
export controlled and has no restrictions.