Thanks to generous donation from time-nut group member xDevs project got hands on broken (dead, no cesium left) atomic time/frequency reference core. It is essentially similar unit that currently used in national level primary clock standards, such as Symmetricom 5071A and contains physics package called Cesium Beam Tube.

Because tube is dead, we can actually now carefully take it apart and document the process for upcoming article, explaining operation and features of such device to realize time reference with exceptionally low uncertainty and without long-term drift.

This tube is out of the older clock, such as model HP 5061B. But because these type of clocks even these old instruments are very expensive on secondary market, especially if can be confirmed working. One of the listing for 5061B is up for $13kUSD and broken ones for over $3k.

Stay tuned for more!