Affordable cesium clock for weak signal detection

[Rob Seastrom]

Ethan Waldo <ewaldo at healthetechs.com> writes:

> I ran
> across [[http://www.popsci.com/technology/article/2011-05/smallest-atomic-clock-ever-now-sale]] a
> couple of months ago in case any of you have $1500 burning a hole in your
> pocket.  If rubidium is a barely acceptable time source for the weak signal
> detection project, perhaps this little integrated chip would do better.

Why is Rb barely acceptable for this?  My understanding is that Rb
actually has a better MVAR than Cs over reasonably short time intervals.

-r