A tachometer using solid state and/or vacuum tube circuitry.
NSN 5950-00-617-7703
NSN 2925-01-648-6859
NSN 5998-00-322-5630
NSN 6620-01-574-1862
NSN 6145-01-085-5556
NSN 5910-01-395-7627
NSN 5990-01-359-8334
NSN 5905-01-502-8044
NSN 6610-01-572-5149
NSN 5999-01-452-9115
NSN 6105-00-012-8278
NSN 5999-00-257-3019