A tachometer using solid state and/or vacuum tube circuitry.
NSN 6650-00-554-1457
NSN 6110-01-397-4176
NSN 5835-01-187-8986
NSN 5905-01-138-1908
NSN 5935-01-509-1518
NSN 4140-00-810-1973
NSN 5999-00-501-0703
NSN 6685-00-287-7564
NSN 5920-00-040-2923
NSN 5945-01-582-1894
NSN 6320-01-522-0318
NSN 5945-00-859-7048