A tachometer using solid state and/or vacuum tube circuitry.
NSN 5975-01-089-4600
NSN 5998-01-328-8288
NSN 5996-01-422-5495
NSN 7035-01-220-6392
NSN 5990-01-219-9018
NSN 5975-01-630-8872
NSN 4140-00-778-8790
NSN 6105-01-165-2684
NSN 5960-01-119-1288
NSN 5999-01-491-1512
NSN 6105-00-678-3355
NSN 6320-00-139-1090