A tachometer using solid state and/or vacuum tube circuitry.
NSN 6220-01-310-5018
NSN 5985-01-051-0701
NSN 5985-00-338-2915
NSN 6145-01-356-3252
NSN 6220-01-239-9889
NSN 5915-01-508-2911
NSN 5915-00-059-5629
NSN 5960-00-054-3946
NSN 5960-00-083-2793
NSN 5990-00-229-4647
NSN 5996-01-030-0052
NSN 5930-01-130-4326