A tachometer using solid state and/or vacuum tube circuitry.
NSN 5895-01-124-4256
NSN 5935-01-233-7176
NSN 5935-00-577-8999
NSN 6150-01-319-2630
NSN 5975-00-306-4688
NSN 6685-01-649-1504
NSN 6130-01-114-2310
NSN 5895-00-260-1806
NSN 6320-00-994-0179
NSN 6220-00-908-1232
NSN 5855-01-218-3735
NSN 6685-01-238-7969