A tachometer using solid state and/or vacuum tube circuitry.
NSN 5925-01-100-3631
NSN 6150-01-569-8650
NSN 5905-01-356-2868
NSN 6645-01-421-0921
NSN 5998-01-123-0689
NSN 5975-00-276-7559
NSN 5985-01-027-1829
NSN 5910-01-033-8044
NSN 5915-01-487-0421
NSN 5905-01-102-7316
NSN 6645-01-553-8500
NSN 5950-00-563-2034