Previous Posts: 20-19, 22-21, 24-23, 26-25, 28-27, 30-29, 33-31, 36-34, 39-37, 42-40, 45-43, 48-46, 51-49, 54-52, 57-55, 60-58, 65-61, 70-66, 71-75, 76-80, 81-85, 86-90, 91-95, 96-100 18) Jack Johnstone Jack Johnstone was key to many of radio's most enjoyable programs. He was at the helm of "Buck Rogers" and "The Adventures of Superman" as it took on multi-part stories with a mix of science fiction and social commentary. He made his…