A tachometer using solid state and/or vacuum tube circuitry.
NSN 5965-00-393-1294
NSN 5895-01-497-3515
NSN 5930-00-004-7750
NSN 6620-01-352-5640
NSN 5925-00-708-8769
NSN 6685-00-575-4647
NSN 6620-01-276-7057
NSN 6130-01-429-0063
NSN 5990-00-847-3806
NSN 6110-01-185-5040
NSN 6130-01-140-6949
NSN 6650-01-530-3763