[time-nuts] Interesting eBay-item?
Tom Van Baak
tvb at leapsecond.com
Thu Feb 2 13:48:02 EST 2006
> Dear List,
> perhaps this item could be of interest to some fellow time-nut?:
> http://cgi.ebay.com/Mercury-Ion-Frequency-Standard ...
See also the mail thread back in October. Same item.
> To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
> Sent: Friday, October 14, 2005 15:10
> Subject: Re: [time-nuts] Mercury Ion Frequency Standard ?
> > 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.
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