A tachometer using solid state and/or vacuum tube circuitry.
NSN 5935-01-114-2389
NSN 6650-00-995-8015
NSN 5950-01-131-1078
NSN 6620-00-155-2608
NSN 5855-00-221-9435
NSN 5930-00-772-2969
NSN 6320-00-456-0836
NSN 5960-00-129-3204
NSN 4140-01-067-2587
NSN 6685-01-445-4301
NSN 5905-00-403-0482
NSN 6650-01-615-0788