[time-nuts] Clock Powers of Ten

Tom Van Baak tvb at LeapSecond.com
Fri Feb 1 04:55:54 EST 2008


> Fun!  What piece of equipment is that Isotemp OCXO (page 28) used in?

Scott, it's from a Trak 8812 GPS Station Clock (an early GPSDO).


> I must say the drip clock was very nice.
> Re the mains frequency, I believe it changes with the load on the grid. 
> Do you have a record of this?

Sylvain, see: http://www.leapsecond.com/pages/mains/


> Very nice, it reminded me of a NYT article about a year ago that 
> describes "the long zoom" as one of the defining aspects of this generation:

Jeff, thanks for the pointer to that one.


> I think in your Powers of Ten you showed a timepiece for which I don't remember 
> any data.  Since it's shown on  the last page does that mean the hour glass has 
> very good specs?

Brooke, I did take "time interval" data on the hour glass but it
was too awkward to manually get enough for a nice adev plot
so I left it out of the talk. I also checked its tempco (room
temperature vs. running in the 'fridge). What I need is someone
to build an optically sensed auto-flipper for an hourglass. Then
not only could a PC collect interval data unattended, but I'd get
about 24 clean samples per day, for weeks or months at a time.
I suspect a frequency drift would show up if left running long
enough.

/tvb




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