A tachometer using solid state and/or vacuum tube circuitry.
NSN 5960-01-381-2478
NSN 6620-01-521-0580
NSN 6240-01-571-3684
NSN 6130-01-397-4845
NSN 5930-01-423-1040
NSN 6150-00-240-8024
NSN 4140-00-274-4002
NSN 6685-00-753-7668
NSN 5960-01-599-9821
NSN 5905-01-456-5194
NSN 6610-01-440-4314
NSN 6130-00-737-0459