High Quality Content by WIKIPEDIA articles! The Mutual Broadcasting System (MBS) was an American radio network, in operation from 1934 to 1999. In the golden age of U.S. radio drama, MBS was best known as the original network home of The Lone Ranger and The Adventures of Superman and as the long-time radio residence of The Shadow. For many years, it was a national broadcaster for Major League Baseball, including the All-Star Game and World Series, and for Notre Dame football. From the mid-1930s and for decades after, Mutual ran a highly respected news service accompanied by a variety of popular commentary shows. Toward the end of its run as a major programmer, it introduced the country to Larry King.