EIA CB-6-A-1987

INTRODUCTION AND SCOPE

This document has been compiled in response to a generally
expressed desire on the part of both users and manufacturers for a
guide to the use of quartz crystal units for frequency control so
that they may be used to their best advantage. The most common
error has been the assumption on the part of some users that the
crystal unit is an absolute frequency-determining device. This idea
has persisted, probably due to the fact that the frequency
tolerances in earlier equipment were sufficiently wide that
frequency variation imposed by the associated circuit conditions
were small enough to be ignored.

It is not the function of this brief document to explain theory
nor to attempt to cover all the eventualities which may arise in
practical circumstances. It does draw attention to some of the more
fundamental questions which should be considered by the user of
quartz crystal units for new applications. Such a procedure will
reduce considerably the user's risk of unsatisfactory
performance.