A tachometer using solid state and/or vacuum tube circuitry.
NSN 5910-01-425-1827
NSN 6610-01-354-3087
NSN 5925-00-328-2136
NSN 5960-01-088-6553
NSN 5996-00-208-3387
NSN 6620-01-537-1326
NSN 6685-01-054-6892
NSN 5925-01-378-2914
NSN 5975-01-181-5679
NSN 5920-01-502-5838
NSN 5945-01-606-3052
NSN 6650-01-609-1993