Crystal Grinder (150) Enlisted Personnel

Grinds and calibrates crystals to be used in crystal-controlled radio sets.
Processes crystal wafers to the required dimensions for a frequency, using small drill press with circular holder revolving between abrasive-coated iron plates. Accurately measures and adjusts frequency of crystal by the use of standard electronic frequency measuring and calibrating equipment, and by hand finishing. Installs and performs first echelon maintenance on equipment, using screw driver, small wrenches, pliers, and hammer.
Must be familiar with all types of crystal cuts and their characteristics. Must know the type of holder to be used, the required crystal activity and tolerances and the type of test unit to be used in calibrating and supplying crystals for any particular set.