Re: Also useful
Why the thumb down? Also my double oven OCXO showed up.
The mini £30 Rb lamps are actually quite easy to use but do have issues: seems that some have off centre pinches and other manufacturing glitches so might need some creative engineering.
This is still a good idea even if it takes more signal processing than I first thought.
Note: Making a SRD from a broken Gunn oscillator is literally nearly impossible but you might luck out. Negative resistance diodes do often run at strange harmonics and the mixer diode is even wider range.
https://pic-microcontroller.com/rubidium-atomic-clock/ (Not mine!)
The argon gas actually increases the frequency slightly but as its a known effect it can be compensated for, also 3D printed silver cavity is feasible with some post printing fine etching to get the exact shape.