[time-nuts] Used Hydrogen Maser, and Mercury Stored-Ion Clocks
Demetrios Matsakis
dnmyiasou at yahoo.com
Thu Jul 11 20:43:11 UTC 2019
For what it’s worth, the mercury ion clocks were shipped to the US Naval Observatory. HP shortly thereafter did a market survey and concluded there was not enough profit in it. They did allow Len and Robin to give short-answer support, and the project fell to me. I found the clocks were not performing well due to sudden vacuum-contamination events. Len, Robin, and I published our data in the proceedings of the 1995 Frequency Control Symposium. At about the same time, JPL came up with a second generation design. They kept improving it, and 20 years later this is now the Deep Space Atomic Clock, which was just launched. See https://www.nasa.gov/mission_pages/tdm/clock/index.html <https://www.nasa.gov/mission_pages/tdm/clock/index.html> and https://en.wikipedia.org/wiki/Deep_Space_Atomic_Clock <https://en.wikipedia.org/wiki/Deep_Space_Atomic_Clock>
As for costs for an unit that is not space-qualified, I would guess you still need a lab with PhD’s and skilled technicians because I doubt much of the hardware is commercially available.
Demetrios Matsakis, as of this Saturday a USNO retiree, and as of August 1 a consultant for Masterclock.
> FWIW, about 20 years ago, Len Cutler and Robin Giffard of 5071A fame
> built several Hg ion clocks to be shipped to some govt customer I
> don't remember. One of the clocks was dropped by the shipping company
> UPS or FedEX) and destroyed. Only then did Len learn that HP was
> self insured, probably as part of a package deal to get a low
> corporate shipping rate. HP products were packed extremely well, so
> the only real risk was the unit getting stolen. I vaguely remember
> Len saying they were out $10K, which was probably just the cost of
> parts. Nevertheless, it didn't seem like building an Hg clock was
> all that big of a project. Way simpler than the 5071A.
> Now a days, the electronics would be considerably easier and cheaper.
> The mechanical parts would all be CNC'ed by an online machine shop.
>
> Rick N6RK
>
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