[time-nuts] 10811 crystal orientation

[Rick Karlquist]

Remember that the SC cut is doubly rotated, so the crystallographic
axes are tilted relative to plane of the blank.  These angles are
published in papers on the SC cut and controlled to extremely tight
tolerances (a few seconds of arc).  However, the 10811 crystal
package is free to rotate to any random angle, so the
crystallographic orientation of a 10811 crystal would only be
consistent if the production line proactively installed them
in a certain orientation.  I don't remember ever hearing about
anyone paying attention to how the crystals were oriented,
in all my years of dealing with the 10811.  If it were important,
knowing how HP did things, the crystal package would be indexed
so that the orientation would not be up to the whim of the
assembler.

Rick Karlquist N6RK