A tachometer using solid state and/or vacuum tube circuitry.
NSN 5950-01-246-0518
NSN 5975-00-253-4198
NSN 5935-00-013-1080
NSN 6650-01-593-2937
NSN 5925-01-601-5567
NSN 6110-01-322-6414
NSN 4140-01-154-9630
NSN 5985-01-206-1355
NSN 6135-00-073-8939
NSN 7035-01-592-2562
NSN 5930-01-527-7417
NSN 5985-00-850-8283