[time-nuts] Cheap Rubidium

[John Miles]

>
> Some isothermal radiation (thermal) shields between the blanket and the
> top of the Rubidium source may also be required.
>
> Unless you have a hydrogen maser you will need to use 3 rubidium sources
> each with its own engine block in order to determine AVAR (using the 3
> cornered hat technique).
> FEI claim that their rubidium sources are actually quieter than typical
> caesium sources so using a caesium reference isn't as effective for
> measuring the short term (< 1day) stability.

That's what I've found, even with no special effort to heat-sink the LPRO's
baseplate.  You need a better-than-average cesium standard to benchmark the
medium-term stability of one of these.  Not bad for $79...

-- john, KE5FX