A tachometer using solid state and/or vacuum tube circuitry.
NSN 6685-01-514-1117
NSN 6110-01-441-9617
NSN 6145-00-498-2738
NSN 5910-00-943-2701
NSN 5960-00-171-9575
NSN 5950-01-624-8591
NSN 6145-01-556-0152
NSN 5910-00-518-2864
NSN 5915-00-564-2490
NSN 5945-01-015-7585
NSN 5915-00-098-4978
NSN 5915-00-563-1558