A tachometer using solid state and/or vacuum tube circuitry.
NSN 6240-01-144-5898
NSN 5855-01-109-6433
NSN 5945-01-503-4327
NSN 5855-00-922-6459
NSN 4140-01-093-8110
NSN 6150-01-472-1933
NSN 6685-01-538-9957
NSN 5855-01-029-8733
NSN 5915-00-155-4766
NSN 6135-00-900-2139
NSN 5935-00-755-2728
NSN 6685-01-035-3891