> one of the world's most precise clocks in his home
Seriously? More precise than the clocks in national labs that contribute to the derivation of UTC? (USNO, NRL, NIST, NPL, NRC, etc) I don't think that is a claim phk has ever made and I am not sure why you are making it for him.
phk has a Stanford Research Systems PRS10 Rubidium Frequency Standard (0 MHz rubidium oscillator)<http://www.thinksrs.com/products/PRS10.htm> at his home. Serial # 005597. The short-term stability of this unit is about 5 × 10-12
This particular PRS10 is GPS referenced _and_ drives one of his GPS referenced NTP servers.
He also has (or had) an array of 10 Motorola Oncore UT+ or M12+T GPS receivers sitting on a row 20cm apart, mounted on a shed roof.
The frequency stability "sigma" of MC #2 has been < 2 x 10-15 during the last year.
NIST-F1, the nation's primary time and frequency standard, is a cesium fountain atomic clock developed at the NIST laboratories. The uncertainty of NIST-F1 is continually improving. In 2000 the uncertainty was about 1 x 10-15, but as of January 2013, the uncertainty has been reduced to about 3 x 10-16
So, no, not "more precise" than the clocks you list, but how many of us have a Rubidium standard in our home?
(And when compared to the large number of clocks in the world, yes, I think that the PRS10 is "one of the most precise".)
So more precise than all of the clocks in the world once you exclude "the most precise clocks in the world"?
Yes, MC#2 is a hydrogen maser clock. But you failed to mention that it is driven by an ensemble of 41 clocks, 4 rubidium fountains, 19 hydrogen masers, and 18 5071 cesiums. And if we are talking about NIST-F1, don't forget F1's new friend, NIST-F2, that is three times as accurate and soon enough the Italians will have there very own version IT-CsF2. And then there are the lattice clocks from JILA...
"One of the most..." doesn't mean "the most". It means there is a group of "the most", which can include a large raw number of objects, but this number is still a tiny fraction of the overall number of things, and his is in that group. It could be the last one in that group, but still in that group. Saying "The united states is one of the most populous nations on earth" doesn't mean it's more populous than China or India, simply that it is up in that rarified group of "mosts".
Seriously? More precise than the clocks in national labs that contribute to the derivation of UTC? (USNO, NRL, NIST, NPL, NRC, etc) I don't think that is a claim phk has ever made and I am not sure why you are making it for him.