[time-nuts] Rubidium Cells for Sale ?!

Attila Kinali attila at kinali.ch
Wed May 8 05:32:52 EDT 2019


On Tue, 7 May 2019 11:36:55 -0400
Bob kb8tq <kb8tq at n1k.org> wrote:

> Before we start hearing “well, noting ever breaks these days” …. how is the
> Galileo system doing for frequency standard reliability ? :)

The PHM seem to suffer from an inherent problem in space.
I had the chance to talk to some of the people from Spectratime
last year at EFTF and learned that the US had the same problems
with hydrogen masers in space. They couldn't solve it so they
dropped the idea of using them for GPS. Unfortunately, this knowledge
ended up only as a sidenote somewhere and the Galileo people learned
of it only _after_ they had problems. AFAIK, the root cause of the
problem is still not know, but continuously running the PHM seems
to mitigate it.

The RAFS IIRC had a nice combination of slight design oversight and
too eager testing, where the test procedure made the device unrealiable.
AFAIK this has been fixed quickly and the last couple of launches shouldn't
have any problems.

			Attila Kinali

-- 
It is upon moral qualities that a society is ultimately founded. All 
the prosperity and technological sophistication in the world is of no 
use without that foundation.
                 -- Miss Matheson, The Diamond Age, Neal Stephenson



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