E.F. Johnson Company Manual. E. F. Johnson Radio Service Manual Series 5100 CD. Material: plastic, paper, metal. Size: 5" x 5 1/2" case; 4 1/2" diameter disk. Description: clear plastic case, black plastic back; white paper insert inside front of plastic case: 5100 Series EF Johnson Digital/Analog Portable Radio, graphic of radios; CD contents: EF Johnson Company 5100 Series Portable Radio Service Manual July 2002.