[time-nuts] Symmetricom CSAC is Cs acting like a Rb unit

WB6BNQ wb6bnq at cox.net
Tue Jan 18 22:02:55 UTC 2011

To the list,

If you listen carefully to the Symmetricom slide show, particularly page 3, it will tell you all you need to


You will discover that that it is indeed a Cesium operated device.  HOWEVER !  It is operated in the same manner
as a Rubidium device.  Doing such does NOT make it a primary standard.

In a Cesium Primary standard, a beam of Cesium atoms are energized to a higher state whose decay give off a
photon of light such that being on frequecy produces more light to the detector.  In the Rb system, the Rb cell
acts simply as a light filter such that when on frequency the light level is reduced as seen by the detector.

This Symmetricom CSAC device uses the same process as the Rb method above.  It uses a laser to push light through
a chamber of Cesium gas.  This Cesium gas is acting as a simple light filter.  So in its current state it will
not rival it superior cousins except in size and power comsumption and possibly price for performance in some


More information about the time-nuts mailing list