A tachometer using solid state and/or vacuum tube circuitry.
NSN 5990-01-027-0568
NSN 5950-00-060-3135
NSN 6150-01-581-9072
NSN 6135-01-501-0833
NSN 6240-00-533-1493
NSN 5945-01-393-4182
NSN 2925-01-496-1068
NSN 6650-00-067-3572
NSN 5999-00-992-7182
NSN 5996-01-640-6852
NSN 5895-01-591-6014
NSN 5925-01-106-3641