Am 26.02.26 um 11:21 schrieb J. J. Lodder:Bill Sloman <bill.sloman@ieee.org> wrote:
When you are happy with a 1.4xyzzy GHz clock frequency,Eh, the basis for the SI is the defined value>
for a -microwave- frequency of the Cesium atom.
From an engineering point of view a Cesium clock
is nothing but a stabilised quartz clock.
That "nothing but" ignores the fact that the output of the cesium clock
has a much more stable frequency than the outputs of regular quartz
clocks. That's why people pay more money for them.
Of course, it is a stabilised quartz clock.
I thought you were proud of being an engineer,
so I adapted the description.
an active Hydrogen maser can do that without an XTAL.
Gerhard
(having locked a h-maser to a zero-g cesium. The maser
has the better phase noise but Cs is the law. That was
somewhat eased b/c everything was at 100 MHz already.)
The Galileo satnav system uses them,
with somewhat mixed succes. Some have failed, iirc.
And, also afaik, Cesium clocks can achieve better long term stability,
(10^-15, for the fountain kind)
Jan
| Date | Sujet | # | Auteur | |
| 23 Feb 26 |  Re: energy and mass | 1090 | Ross Finlayson | |
| 23 Feb 26 |  Re: energy and mass | 1075 | J. J. Lodder | |
| 24 Feb 26 |   Re: energy and mass | 1074 | J. J. Lodder | |
| 24 Feb 26 |  Re: energy and mass | 1073 | Ross Finlayson | |
| 24 Feb 26 |  Re: energy and mass | 1 | J. J. Lodder | |
| 25 Feb 26 | Re: energy and mass | 1071 | Bill Sloman | |
| 25 Feb 26 | Re: energy and mass | 1069 | J. J. Lodder | |
| 25 Feb 26 | Re: energy and mass | 1 | Ross Finlayson | |
| 25 Feb 26 | Re: energy and mass | 2 | john larkin | |
| 26 Feb 26 | Re: energy and mass | 1 | J. J. Lodder | |
| 26 Feb 26 | Re: energy and mass | 1026 | Bill Sloman | |
| 26 Feb 26 | Re: energy and mass | 1 | Maciej Woźniak | |
| 26 Feb 26 | Re: energy and mass | 4 | Gerhard Hoffmann | |
| 26 Feb 26 | Re: energy and mass | 3 | J. J. Lodder | |
| 26 Feb 26 | Re: energy and mass | 2 | Gerhard Hoffmann | |
| 26 Feb 26 | Re: energy and mass | 1 | Domingo Totolos | |
| 26 Feb 26 | Re: energy and mass | 1019 | Ross Finlayson | |
| 26 Feb 26 | Re: energy and mass | 527 | Maciej Woźniak | |
| 26 Feb 26 | Re: energy and mass | 526 | Ross Finlayson | |
| 26 Feb 26 | Re: energy and mass | 3 | Maciej Woźniak | |
| 26 Feb 26 | Re: energy and mass | 2 | Maciej Woźniak | |
| 26 Feb 26 | Re: energy and mass | 1 | Ross Finlayson | |
| 28 Feb 26 | Re: energy and mass | 522 | Thomas Heger | |
| 28 Feb 26 | Re: energy and mass | 518 | Bill Sloman | |
| 1 Mar 26 | Re: energy and mass | 517 | Thomas Heger | |
| 1 Mar 26 | Re: energy and mass | 516 | Bill Sloman | |
| 3 Mar 26 | Re: energy and mass | 515 | Thomas Heger | |
| 3 Mar 26 | Re: energy and mass | 514 | Bill Sloman | |
| 5 Mar 26 | Re: energy and mass | 513 | Thomas Heger | |
| 5 Mar 26 | Re: energy and mass | 512 | Bill Sloman | |
| 5 Mar 26 | Re: energy and mass | 10 | Jeroen Belleman | |
| 5 Mar 26 | Re: energy and mass | 9 | Thomas 'PointedEars' Lahn | |
| 6 Mar 26 | Re: energy and mass | 8 | Ross Finlayson | |
| 6 Mar 26 | Re: energy and mass | 7 | john larkin | |
| 7 Mar 26 | Re: energy and mass | 6 | Bill Sloman | |
| 7 Mar 26 | Re: energy and mass | 5 | Ross Finlayson | |
| 7 Mar 26 | Re: energy and mass | 3 | john larkin | |
| 7 Mar 26 | Re: energy and mass | 2 | Bill Sloman | |
| 7 Mar 26 | Re: energy and mass | 1 | Ross Finlayson | |
| 7 Mar 26 | Re: energy and mass | 1 | Bill Sloman | |
| 5 Mar 26 | Re: energy and mass | 5 | Ross Finlayson | |
| 5 Mar 26 | Re: energy and mass | 1 | Don | |
| 5 Mar 26 | Re: energy and mass | 2 | Don | |
| 5 Mar 26 | Re: energy and mass | 1 | Ross Finlayson | |
| 5 Mar 26 | Re: energy and mass | 1 | Bill Sloman | |
| 8 Mar 26 | Re: energy and mass | 496 | Thomas Heger | |
| 8 Mar 26 | Re: energy and mass | 495 | Bill Sloman | |
| 10 Mar 26 | Re: energy and mass | 494 | Thomas Heger | |
| 10 Mar 26 | Re: energy and mass | 101 | Ross Finlayson | |
| 10 Mar 26 | Re: energy and mass | 77 | john larkin | |
| 10 Mar 26 | Re: energy and mass | 1 | Ross Finlayson | |
| 10 Mar 26 | Re: energy and mass | 5 | Jeroen Belleman | |
| 10 Mar 26 | Re: energy and mass | 3 | john larkin | |
| 10 Mar 26 | Re: energy and mass | 1 | Ross Finlayson | |
| 11 Mar 26 | Re: energy and mass | 1 | Bill Sloman | |
| 11 Mar 26 | Re: energy and mass | 1 | Bill Sloman | |
| 11 Mar 26 | Re: energy and mass | 70 | Thomas Heger | |
| 11 Mar 26 | Re: energy and mass | 62 | john larkin | |
| 12 Mar 26 | Re: energy and mass | 12 | john larkin | |
| 12 Mar 26 | Re: energy and mass | 5 | Bill Sloman | |
| 12 Mar 26 | Re: energy and mass | 4 | john larkin | |
| 13 Mar 26 | Re: energy and mass | 3 | Bill Sloman | |
| 13 Mar 26 | Re: energy and mass | 2 | john larkin | |
| 14 Mar 26 | Re: energy and mass | 1 | Bill Sloman | |
| 12 Mar 26 | Re: energy and mass | 6 | J. J. Lodder | |
| 12 Mar 26 | Re: energy and mass | 5 | john larkin | |
| 12 Mar 26 | Re: energy and mass | 1 | J. J. Lodder | |
| 13 Mar 26 | Re: energy and mass | 3 | Bill Sloman | |
| 13 Mar 26 | Re: energy and mass | 2 | john larkin | |
| 14 Mar 26 | Re: energy and mass | 1 | Bill Sloman | |
| 12 Mar 26 | Re: energy and mass | 13 | Bill Sloman | |
| 12 Mar 26 | Re: energy and mass | 12 | J. J. Lodder | |
| 12 Mar 26 | Re: energy and mass | 11 | Bill Sloman | |
| 12 Mar 26 | Re: energy and mass | 10 | J. J. Lodder | |
| 13 Mar 26 | Re: energy and mass | 9 | Bill Sloman | |
| 13 Mar 26 | Re: energy and mass | 8 | Bill Sloman | |
| 14 Mar 26 | Re: energy and mass | 7 | Bill Sloman | |
| 14 Mar 26 | Re: energy and mass | 6 | Maciej Woźniak | |
| 14 Mar 26 | Re: energy and mass | 5 | Bill Sloman | |
| 15 Mar 26 | Re: energy and mass | 4 | Bill Sloman | |
| 15 Mar 26 | Re: energy and mass | 3 | Bill Sloman | |
| 15 Mar 26 | Re: energy and mass | 2 | Maciej Woźniak | |
| 15 Mar 26 | Re: energy and mass | 1 | Bill Sloman | |
| 13 Mar 26 | Re: energy and mass | 36 | Thomas Heger | |
| 13 Mar 26 | Re: energy and mass | 35 | Bill Sloman | |
| 14 Mar 26 | Re: energy and mass | 34 | Thomas Heger | |
| 14 Mar 26 | Re: energy and mass | 33 | Bill Sloman | |
| 15 Mar 26 | Re: energy and mass | 32 | Thomas Heger | |
| 15 Mar 26 | Re: energy and mass | 31 | Bill Sloman | |
| 16 Mar 26 | Re: energy and mass | 1 | Bill Sloman | |
| 19 Mar 26 | Re: energy and mass | 29 | Thomas Heger | |
| 19 Mar 26 | Re: energy and mass | 27 | Bill Sloman | |
| 20 Mar 26 | Re: energy and mass | 26 | Thomas Heger | |
| 20 Mar 26 | Re: energy and mass | 25 | Bill Sloman | |
| 21 Mar 26 | Re: energy and mass | 24 | Thomas Heger | |
| 21 Mar 26 | Re: energy and mass | 14 | john larkin | |
| 21 Mar 26 | Re: energy and mass | 13 | Ross Finlayson | |
| 21 Mar 26 | Re: energy and mass | 10 | john larkin | |
| 21 Mar 26 | Re: energy and mass | 9 | Ross Finlayson | |
| 21 Mar 26 | Re: energy and mass | 8 | john larkin | |
| 22 Mar 26 | Re: energy and mass | 7 | J. J. Lodder | |
| 21 Mar 26 | Re: energy and mass | 2 | Bill Sloman | |
| 21 Mar 26 | Re: energy and mass | 9 | Bill Sloman | |
| 19 Mar 26 | Re: energy and mass | 1 | Ross Finlayson | |
| 11 Mar 26 | Re: energy and mass | 7 | Ross Finlayson | |
| 10 Mar 26 | Re: energy and mass | 5 | Ross Finlayson | |
| 11 Mar 26 | Re: energy and mass | 18 | Paul B. Andersen | |
| 10 Mar 26 | Re: energy and mass | 392 | Bill Sloman | |
| 28 Feb 26 | Re: energy and mass | 2 | Ross Finlayson | |
| 1 Mar 26 | Re: energy and mass | 1 | Thomas Heger | |
| 28 Feb 26 | Re: energy and mass | 491 | Thomas Heger | |
| 26 Feb 26 | Re: energy and mass | 1 | Bill Sloman | |
| 28 Feb 26 | Re: energy and mass | 39 | Don | |
| 25 Feb 26 | Re: energy and mass | 1 | Ross Finlayson | |
| 24 Feb 26 | Re: energy and mass | 14 | Bill Sloman |
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