A tachometer using solid state and/or vacuum tube circuitry.
NSN 5930-01-124-8001
NSN 5910-01-364-1078
NSN 5855-01-392-3734
NSN 5990-00-324-4454
NSN 5999-00-203-1202
NSN 5855-01-398-0090
NSN 6130-01-436-3328
NSN 7035-01-074-2343
NSN 6135-01-322-4655
NSN 5910-01-130-2531
NSN 5975-00-963-4695
NSN 5925-01-004-9293