Tom Moeller, 28th Maintenance Squadron precision measurement equipment lab technician, removes a printed circuit assembly unit from an Anritsu 68347C synthesized signal generator after a calibration test at their lab on Ellsworth Air Force Base, S.D., Feb. 20, 2013. The printed circuit assembly unit was producing erratic frequencies and required a new circuit board. (U.S. Air Force photo by Airman 1st Class Anania Tekurio/Released)