Ground:  The position of lowest potential energy.  The radio wave energy has returned to rest. "Earth ground The earth ground connection effectively extends the antenna into the earth, which contains electrical signals. Keep the ground wire as short and straight as possible. There may be some sensitivity loss if the excess ground wire is coiled into a loop. Use either a metal cold water pipe that is buried at least several feet in the ground or an electrical conduit that is similarly buried or grounded. You can usually make a satisfactory ground connection using the screw that fastens the cover plate to an electrical outlet box."  (RadioWrinkles) "GIs used their bayonets buried to the hilt in moist earth for a ground connection."  (Adamson)