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 5990-00-140-4559
NSN 5855-01-180-5369
NSN 5835-00-121-7558
NSN 4140-01-167-7574
NSN 7035-01-014-3808
NSN 5960-01-632-6576
NSN 5895-01-528-7486
NSN 6145-01-562-1436
NSN 6220-01-329-7759
NSN 6105-01-305-9118
NSN 7035-00-001-4586
NSN 2925-01-161-7440