sentences:  The BC-224-A, -B, -C, and -D, and the BC-348-B, and -C, tuned 1.5-18 MHz in six bands.The Signal Corps had the receiver design modified to add a 200-500 kHz band and compress the 1.5-18 MHz coverage into the remaining five bands.This modified design became the BC-224-E and the BC-348-E.