Radio Set SCR-506-A (fig. 1) is a medium power, amplitude-modulated set made up of Radio Receiver BC- 652-A, Radio Transmitter BC-653-A, and certain additional operating components (par. 4). It is designed for installation in tanks, amphibian trucks, personnel carriers, and other vehicles to provide continuous-wave (c-w) and voice communi- cation from one vehicle to another or between these vehicles and airplanes or base stations.