[time-nuts] fleabay cesium

[Hal Murray]

> I have a few GPSDO's (Trimble T-Bolt, Z3801A, TrueTime & HB units).
> How much better can the Cesium be than any of those ??

Here is another viewpoint...  (I don't own a Cesium (but I'm looking) so my 
opinions may not be relevant.)

What are you after?  What is important to you?

Under the covers, a "Cesium" is just a CesiumDO with the PLL parameters tuned 
to take advantage of what the Cesium tube can deliver.  The basic time 
constant is sub-second vs many-seconds for a GPSDO.

If you are nutty enough, the GPSDO numbers don't really match what a Cesium 
can deliver in the medium term time scale, say 1000-10000 seconds.  I'm 
pretty sure I've seen graphs of GPS time shifting slightly from night to day 
due to atmospheric changes.  A Cesium won't do that.

On the other hand, a GPSDO won't have any long term drift.  It's locked to 
the best time we can get.  If you wait long enough a Cesium will drift.  Not 
very fast, but it will drift.



-- 
These are my opinions, not necessarily my employer's.  I hate spam.