A tachometer using solid state and/or vacuum tube circuitry.
NSN 5925-01-368-6790
NSN 5920-01-228-4384
NSN 6620-01-420-1735
NSN 5930-01-493-6145
NSN 6645-01-319-0006
NSN 5920-01-461-8719
NSN 6650-01-461-4807
NSN 5895-00-979-3882
NSN 6130-01-354-9306
NSN 6620-01-519-2628
NSN 5985-00-189-0953
NSN 6240-01-419-5923