[time-nuts] Confirm Operation Problem Found
Brooke Clarke
brooke at pacific.net
Fri Jan 7 14:27:15 EST 2005
Hi:
I found the problem just prior to midnight. My GPS receiver DC power
cord was unplugged for some time, maybe a month or so and the Rb source
was just freewheeling.
Also found a really neat way to make a time interval measurement in
Appendix A of the PRS10 manual. The setup is:
PRS10 feeds the External Reference input to the SR 620 counter and the
"A" TI input.
The Device Under Test 10 MHz feeds the "B" input.
Both of these are set for 50 Ohms and AC coupling with auto trigger
level setting (full CCW on the knob).
A coax between the 1 kHz TTL Reference output and the external Arm input
set for positive TTL triggering.
Mode = Time Interval
Start trigger source = A
Sample size = 1,000
Display = Mean
Now every second the time interval is displayed and looks like 31.143
nano seconds (i.e. LSD is 1 pico second).
Based on a 14 minute observation the FTS4060 may be off 3E-12.
Any inputs on how to setup the PRS10 for best performance for this type
of use?
Having Fun,
Brooke
--
w/Java http://www.PRC68.com
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml
http://www.precisionclock.com
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