Review of the revised military specification for quartz crystal oscillators

Revision B of the military specification for quartz crystal oscillators, MIL-0-553108, is expected to be released during 1987 .This document will supercede MIL-0-55310A. It will permit the specification and acquisition of more-reliable and higher-performance crystal oscillators required by modern military equipment. Major modifications and improvements were made to requirements specifying design and construction, performance and test, quality assurance, and qualification. Definitions were expanded and two new oscillator types, the MCXO (Microcomputer-compensated-crystal oscillator) and the RbXO (Rubidium-crystal oscillator) were added. Some of the changes discussed are modifications of frequency-stability and aging requirements, and the introduction of several new requirements such as "Initial frequencyaging," "Initial frequency-temperature accuracy including hysteresis and trim effect," and "Phase noise, vibration." Design and construction requirements changes, and new quality assurance provisions that include 100% environmental stress screening, and certification of hybrid facilities and lines, are reviewed.