I got a "removed from service" EFRATOM 10 MHz rubidium standard from eBay for $80 or so and stuck it in an old 1U rackmount case along with a $20 MeanWell p/s to make my reference standard:
![](http://www.paladinmicro.com/TestEquipment/HPIM0844.JPG)
![](http://www.paladinmicro.com/TestEquipment/HPIM0850.JPG)
THe rotary switch and panel meter let you monitor the lamp, crystal and LOCK voltages.It takes about 75 seconds to lock from a cold start.