[time-nuts] Sign of Time Interval & SR620 Trick

Brooke Clarke brooke at pacific.net
Fri May 19 20:15:26 EDT 2006


I've started looking at the time interval where the start is from cesium 
standard # 1227 and the stop is from cesium standard #1013.
I think # 1227 is good for some parts in E-13 and # 1013 needs 
adjustment.  The TI is increasing a few pS every second.
Which way is does 1013 need to be adjusted?  Is their some memory trick 
to keep this straight?

------------------SR620 Trick--------------
What I thought was a problem with my SR620 turned out to be a rollover 
problem.  If you're using the SR620 counter instead of using a 1 or 10 
Mhz signal from the standard as the stop input (GPS is the start input) 
feed a 10 Mhz signal into the rear panel external reference input.  Use 
the SEL, SET and SCALE ^ V keys to enable the rear panel reference 
input.  Then feed the front panel 1 kHz REF output to the B stop input.  
This improves the rollover problem by 1,000 to 1 mS.  Note the SR620 
reference output signal is tightly coupled to and aligned with the 
external reference input, it is not just a simple oscillator.

Have Fun,

Brooke Clarke

w/Java http://www.PRC68.com
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml

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