A tachometer using solid state and/or vacuum tube circuitry.
NSN 6320-00-242-3300
NSN 6105-00-125-7964
NSN 6240-01-139-3377
NSN 6620-00-043-6082
NSN 6240-01-378-2213
NSN 6220-01-069-2340
NSN 6610-01-473-1843
NSN 5925-01-472-9133
NSN 5930-01-022-9632
NSN 6645-01-434-5674
NSN 6110-00-538-1313
NSN 6220-00-033-7234