A tachometer using solid state and/or vacuum tube circuitry.
NSN 5935-01-449-6893
NSN 6110-01-258-7147
NSN 6145-01-311-2799
NSN 5905-00-533-7287
NSN 6135-00-973-5632
NSN 6150-01-435-4483
NSN 5960-01-023-8037
NSN 7035-01-571-8784
NSN 6320-00-070-4544
NSN 5920-00-351-8428
NSN 5910-01-332-7456
NSN 5950-01-091-0205