[time-nuts] What’s the BEST crystal?

[Attila Kinali]

On Sat, 29 Feb 2020 17:01:27 -0500
Bob kb8tq <kb8tq at n1k.org> wrote:

> > Isn't that where "whispering gallery" modes come into the picture ?
> 
> …… and done with sapphire. 
> 
> This is the real answer to “why is nobody going to do this?”. You already
> have something ( the sapphire resonators ) that does better than 
> anything you could reasonably expect.

It's the other way round. Yes, we have *a* solution for better phase noise
and stability, but not *the* solution. A CSO is a full size 19" rack
filled with equipment that needs constant maintenance. Nothing you can
put on a satellite, much less carry around. People wouldn't even put it
in cellphone base station, although they would love to have the additional
frequency stability and phase noise performance to squeeze in some
more customers into the limited frequency space. 

It is actually very hard to beat crystal oscillators and vapor cell
frequency standards in the stability/phase noise/size/power consumption/cost
trade-off. And until recently, quartz oscillators and vapor phase
standards occupied seperate areas in this trade-off space. Until the
CSAC came around and connected them.


			Attila Kinali
-- 
<JaberWorky>	The bad part of Zurich is where the degenerates
                throw DARK chocolate at you.