[time-nuts] Fury - Rubidium

SAIDJACK at aol.com SAIDJACK at aol.com
Wed Jul 28 06:02:18 UTC 2010


Hi Scott,
 
a cool thing to try is to put the unit into manual holdover by issuing  the 
command
 
   sync:holdover:init
 
The unit will act as if the GPS antenna has been removed, but GPSCon will  
continue to show the 1PPS phase drift against GPS. Thus you can see how 
stable  your LPRO is over time when the unit is in holdover.

You can restart normal locking with the command
 
   sync:holdover:rec:init
 
On a good DOCXO, we would see less than 2000ns drift over a day when the  
unit has been stable for a week or so. I believe the limits of the time 
interval  display are about +/- 2000ns.
 
bye,
Said
 
 
In a message dated 7/27/2010 08:42:01 Pacific Daylight Time, smace at intt.net 
 writes:

I test  it by changing the antenna delay.  It should recover within a  
reasonable time.  Bumping the coarsedac is typically too much change  and 
takes longer to recover.  I run it with a 20ns offset to my  z3801a, and 
they always stay within 20ns of other.

I've had the  Fury running for about 5400 hours since the last reboot, 
running v1.21  firmware.  It stays within +-10ns,  usually it's between  
+-5ns.  Over 24hrs, gpscon reports TI average 0.15 or so and stddev  
around 2.5ns.



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