[time-nuts] 8040c specification clarification, help for a time-nut beginner

Pee Akka akkapee at gmail.com
Thu Dec 12 05:22:26 EST 2013


I'm currently doing my master's thesis on GPSDO devices. Nothing fancy but
more than enough for a fledgling time-nutter. It seems that which ever
direction I go with my master's, this place always pops up :)

I'm a bit uncertain about how to interpret one of the GPSDO's
specifications. The device in question is a a 8040c Rubidium Frequency
Standard with a SA.22C-LN oscillator (ie. the low noise version). The
specification states that its frequency accuracy (ie frequency offset)
after 20 minutes of 1PPS GPS-disciplining is <1E-12.

Do you think this specification the combined accuracy of the GPS receiver
and 8040c device? In another words, if the 8040c is locked to GPS, is the
whole receiver+8040c system's combined accuracy <1E-12? The GPS receiver
that I have in use is XLi-GPS with +-30ns RMS 1PPS output.

The datasheet for 8040c is here:
http://www.symmetricom.com/resources/download-library/documents/datasheets/8040c/

The measurements that I've done indicate that at least the frequency
stability (ADEV) of the 8040c is between 9E-13 and 1E-12 from 1s to 1000s.

Thanks in advance.


More information about the time-nuts mailing list