A tachometer using solid state and/or vacuum tube circuitry.
NSN 5990-01-433-3786
NSN 6610-01-287-9814
NSN 6620-00-494-3718
NSN 6645-01-461-3581
NSN 7035-00-117-0418
NSN 5915-01-219-7068
NSN 5920-00-621-6601
NSN 5920-01-431-2174
NSN 5835-01-302-2745
NSN 5945-01-576-7533
NSN 5925-00-420-7675
NSN 6145-01-252-5356