A tachometer using solid state and/or vacuum tube circuitry.
NSN 5960-01-037-7988
NSN 5905-01-204-8737
NSN 5935-01-649-9465
NSN 6130-01-594-0566
NSN 6620-01-652-4349
NSN 4140-01-226-0637
NSN 5925-01-264-8107
NSN 6135-00-228-8140
NSN 5925-01-576-8516
NSN 5965-01-043-9357
NSN 5835-01-632-6627
NSN 5920-01-481-0421