[time-nuts] Ashtech Z-12-R Operation?

Brooke Clarke brooke at pacific.net
Fri May 29 19:28:37 UTC 2009

Hi Tom:

How can I tell if the external clock is working?

I'm using Thunderbolt -> HP 8648A -> Z-12.

Have Fun,


Tom Van Baak wrote:
>> Hi:
>> I got an Ashtech Z-12-R that powers up and displays the start up 
>> screen, see:
>> http://www.prc68.com/I/AshtechZ12.shtml
>> But it does not progress or respond to button presses.  Does someone 
>> have a pdf manual or know how to kick start one of these?
> Brooke,
> My Z12-T requires an external 20 MHz reference clock; I'm not
> familiar with your -R model but it too may require this. It's not
> uncommon for high-end geodetic-grade timing receivers to rely
> on an external clock (e.g., cesium or maser). The idea is that
> all received GPS signals are referenced to a real external clock
> instead of an internal or virtual gps clock, or something like that.
> So try that first. The quality of the 20 MHz is not important just
> to see if it starts working. But clearly, to get good results, you'll
> want to lock your 20 MHz to something atomic.
> When I got my Z12 I played a bit with how to get 20 MHz. See:
> http://www.leapsecond.com/pages/20mhz/
> /tvb

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