euclid The Time Traveler's Clock, User Manual

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latitude independently from that supplied by the CSAC GPS Disciplined Oscillator. The
Maxim RTC system was unchanged except for software refinements.
The gimbal support and servo system were like those on the Cesium Breadboard
Prototype. The problem of not being able to manually wind the chronometer without
disassembling the housing remained and needed to be fixed.
Figure 6: Pyramid Time Traveler’s Clock
It was found that a redundant GPS systems was not needed, because a CSAC GPS
Disciplined Oscillator (either cesium or rubidium) provided date, latitude, longitude, and
time from the atomic reference, maintaining accuracy to a millisecond per year.
Cube Box Rubidium Prototype
The inventor decided that the pyramid enclosure, while having an interesting
appearance, was not very space-efficient, and he decided to go with a more traditional,
cubical, mahogany box, like what has been traditionally used for marine chronometers,
but increased in size (having more internal volume and a smaller footprint than the
pyramid). The cube box had a lower section (about 2/3 of the height) that enclosed all
the circuits, batteries, and chronometer. A display panel was mounted behind the
chronometer, and a row of display lights and switches was placed across the front of the
chronometer. The upper section of the box was hinged and latched to the lower
section, covering the chronometer and controls. It allowed the user to see all the
displays, switches, and chronometer through a clear window. Above the upper section
was a hinged lid and latch to close the box.
In this prototype the atomic reference was a stand-alone rubidium miniature atomic
clock (MAC) from Jackson Labs. This oscillator was calibrated with a GPS-disciplined
reference clock before use. The 10MHz output of the MAC was connected to an input
on the GPS module (a ublox EVK-M8F) to supply the chip with a precision time base to