A tachometer using solid state and/or vacuum tube circuitry.
NSN 2925-01-445-4095
NSN 6620-00-862-5567
NSN 6220-01-146-8233
NSN 5910-00-810-1425
NSN 5925-00-056-8931
NSN 5985-01-043-3214
NSN 6685-01-437-1357
NSN 5975-00-446-7875
NSN 6150-01-528-7949
NSN 6240-01-442-7746
NSN 5999-01-487-8856
NSN 6685-00-596-8765