A tachometer using solid state and/or vacuum tube circuitry.
NSN 6685-01-292-6643
NSN 6320-01-429-9871
NSN 6240-01-371-3020
NSN 6105-00-056-9776
NSN 5895-01-054-6492
NSN 6130-01-486-9723
NSN 6650-01-039-2858
NSN 5925-01-455-4411
NSN 5910-00-770-4748
NSN 5996-00-803-6475
NSN 5855-01-294-2804
NSN 5930-01-472-3953