Critcal due to fit requirments.
An item that can generate a fundamental frequency with a high degree of accuracy. Harmonics of this fundamental are then used as a reference point for checking throughout the radio spectrum. The standard may be stable crystal oscillator, noncrystal oscillator, tuning fork, atomic beam, molecular beam, gas cell, quantum mechanical resonator, or the like.
Classification: Parts and accessories of articles of schedule b subheading 9030.39
NSN 5835-01-632-6627
NSN 6110-01-400-4207
NSN 6685-00-661-2347
NSN 5915-00-802-3442
NSN 6150-01-392-5143
NSN 4140-00-770-8404
NSN 6150-01-141-0115
NSN 5935-00-985-3851
NSN 5835-01-018-6294
NSN 5855-01-502-9900
NSN 5990-01-222-8570
NSN 5950-00-877-8713