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 6650-00-915-8545
NSN 4140-00-669-6109
NSN 5905-00-693-2839
NSN 6150-01-210-9204
NSN 5960-01-426-4242
NSN 6610-01-589-5146
NSN 5945-01-252-8662
NSN 5935-00-603-0466
NSN 6685-01-014-2049
NSN 5975-01-461-7852
NSN 6685-00-058-9526
NSN 5855-00-287-5870