[mananaysiempre]

From what I remember of textbook discussions of atomic clocks, stabilizing drifting oscillators is also in part how normal, old (50+ years) atomic clocks work as well, isn’t it? You have a fiddly and unreasonably high-frequency reference, you slave a relatively garden-variety standard like an environmentally controlled piezoelectric crystal to it, and then feed your periodic signals, counters, etc. off that.

[willis936]

Yes. Surprisingly, atomic clocks have high jitter compared to ovenized quartz oscillators. Every atomic clock package is outputting its signal from a quartz oscillator that is disciplined by the atomic oscillator.