A tachometer using solid state and/or vacuum tube circuitry.
NSN 5920-01-231-9175
NSN 6620-00-150-6514
NSN 5925-01-373-2324
NSN 5950-01-587-4668
NSN 6685-00-053-5558
NSN 5855-01-020-7982
NSN 5910-00-179-1095
NSN 6135-01-412-0404
NSN 6685-00-134-6305
NSN 6110-01-492-9694
NSN 6145-00-838-6613
NSN 5975-00-838-0443