[time-nuts] Mercury Ion Frequency Standard ?
Tom Van Baak
tvb at leapsecond.com
Fri Oct 14 19:10:13 EDT 2005
> Have you seen this?
> Mercury Ion Frequency Standard Set
> ebay # 7554448004
> Probably an HP prototype, looks not really recent... 1980s? anyone knows
> Marco IK1ODO
HP worked on Hg ion standards in the late 70's.
There was a paper about it published in 1981.
Performance claims were 1e-12 accuracy; 2e-13
reproducibility; and 1e-12 root tau stability; about
the same as a 1980's era cesium. This unit might
be one that HP delivered to USNO for evaluation.
What you see for sale is just the electronics bay.
All the good stuff (the actual physics rack) is
missing and who knows where it is, possibly still
at USNO. Note the thick bundle of cut wires.
So all you get is a miscellaneous collection of a
dozen HP and Varian instruments, which you
could buy separately (if you even wanted them)
for a fraction of the opening bid.
More information about the time-nuts