[time-nuts] Sign of Time Interval & SR620 Trick
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?
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.
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml
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