[time-nuts] historical question

Tom Van Baak tvb at LeapSecond.com
Fri Jul 13 15:48:22 EDT 2007

> hello time-nuts,
> i have a friend who called me on a question of hewlett packard
> and their usage of patek philippe clock displays in their devices.
> he was asking me when the first device was built with that clock  
> display.
> i was not 100% sure, so i post this question here.
> does anybody have some information about the product history of those
> cesiums and what they looked like through the early years?
> best regards,
> sebastian

Hi Sebastian,

The hp 5060A cesium standard did not have 1PPS or clock.

The hp 5061A, option 001 added 1PPS and clock display.
In the early years this was the analog Patek Philippe clock
that you mention. Later it was replaced with a red LED digital
clock. I don't have exact dates for these but could look them
up for you if necessary. The Patek clocks were also used
for the hp 5065A rubidium standards with option 001. You'll
also see the clock used in early Tracor and Austron units.

In the hp 5061B, option 001 was an LCD digital clock.

There are photos of these three cesium standards at:
  The Museum of HP Clocks

If you need additional pictures or information, let me know.


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