A tachometer using solid state and/or vacuum tube circuitry.
NSN 5835-01-475-5714
NSN 5950-01-590-3921
NSN 5945-01-617-1673
NSN 4140-01-398-5958
NSN 6105-01-501-7372
NSN 5975-01-426-8968
NSN 5925-00-179-0094
NSN 6145-01-189-7622
NSN 5960-00-058-1181
NSN 5990-01-602-6701
NSN 6240-01-599-0652
NSN 6240-01-285-7857