A tachometer using solid state and/or vacuum tube circuitry.
NSN 5999-01-302-0715
NSN 6645-00-950-8845
NSN 5950-01-468-5431
NSN 6320-01-466-4175
NSN 6645-01-351-1154
NSN 5910-01-353-2747
NSN 6320-01-272-7072
NSN 5999-00-010-4777
NSN 5975-01-283-4085
NSN 7035-01-323-0164
NSN 5950-00-499-7518
NSN 5950-00-725-9363