A tachometer using solid state and/or vacuum tube circuitry.
NSN 5895-00-147-9998
NSN 6620-01-448-8926
NSN 6620-00-179-9079
NSN 5965-01-114-9086
NSN 5935-01-571-6163
NSN 6320-01-326-1316
NSN 5960-01-260-3973
NSN 5985-01-368-2972
NSN 5990-01-546-1649
NSN 6145-00-230-5268
NSN 6220-00-796-4977
NSN 5920-01-442-7685