A tachometer using solid state and/or vacuum tube circuitry.
NSN 5975-01-432-5846
NSN 5975-01-487-1533
NSN 6150-01-247-6744
NSN 5975-01-132-1312
NSN 5998-01-320-9862
NSN 5990-01-266-5240
NSN 6240-00-681-1713
NSN 6320-01-116-3980
NSN 2925-01-055-7607
NSN 5996-01-071-8043
NSN 2925-01-092-7335
NSN 5945-01-250-3888