A tachometer using solid state and/or vacuum tube circuitry.
NSN 5920-01-510-3933
NSN 6610-00-764-4015
NSN 6135-00-416-2898
NSN 5998-00-854-0880
NSN 6645-01-147-4603
NSN 5960-01-448-3497
NSN 6105-01-337-6806
NSN 5920-01-241-0212
NSN 5915-01-277-9611
NSN 5965-00-113-9748
NSN 5935-01-474-9084
NSN 6645-00-634-9317