A tachometer using solid state and/or vacuum tube circuitry.
NSN 6240-01-371-3020
NSN 6240-01-628-9240
NSN 5910-01-222-1624
NSN 5855-01-487-5048
NSN 5950-01-520-6385
NSN 5990-01-237-7989
NSN 5930-00-917-4388
NSN 5895-01-147-5688
NSN 6320-00-242-3300
NSN 6130-01-244-8772
NSN 5935-00-411-3688
NSN 6145-00-843-8744