Radio maintenance: it hertz to be this good
Airman Johnrafael Pena, a 28th Communications Squadron radio frequency technician, uses an oscilloscope at Ellsworth Air Force Base, S.D., Sept. 5, 2018. The radio maintenance shop conducts repairs for radios on base to ensure they will work properly when needed. (U.S. Air Force photo by Airman 1st Class Thomas Karol)