A tachometer using solid state and/or vacuum tube circuitry.
NSN 6650-01-502-6761
NSN 4140-01-545-6020
NSN 5950-00-078-1492
NSN 5998-01-573-7441
NSN 2925-01-545-2717
NSN 7035-01-552-8475
NSN 4140-01-226-6944
NSN 5975-00-484-2223
NSN 6110-01-159-6898
NSN 5925-01-392-6382
NSN 6130-01-550-6385
NSN 5835-01-232-1226