[time-nuts] Frequency Stability of Trimble Mini-T

Mike Feher mfeher at eozinc.com
Mon Oct 6 01:34:45 UTC 2008


The attached URL is a 11 day plot of a 30.5 GHz carrier taken every minute
by an Agilent 53152A microwave counter. The Mini-T has an ovenized
oscillator. It appears that the GPS attempts to over correct the oscillator,
hence the large frequency excursions. The real large excursions, around the
96 hour range, were due to a loose connector. The requirements are such that
over a 90 day period the total frequency drift shall be no more than 1 KHz.
Someone in their ultimate wisdom, decided that since they do not have the
time to take measurements for 90 days, they will take it for 24 hours and
not allow any frequency excursions over 11 Hz at 30.5 GHz. Obviously, this
plot does not pass their requirement. When the oscillator is allowed to free
run, the frequency jumps are not there. Has any one else made any
measurements on the Trimble Mini-T. Any observations or suggestions are
appreciated. Regards - Mike

http://www.eozinc.com/11dayplot.pdf

 
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960
 
 




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