Conrad sure kept busy in the radio world, that’s for sure. There were really only just a handful of actors that did the lion’s share of radio roles. Howard Mcnear, Parley Baer, Harry Bartell, John Dehner and just a few others that are in just about everything, everytime.
My vote for the most iconic radio voice is Gerald Mohr “Phillip Marlowe”, who also played roles on numerous radio shows. Even though his stature matched his voice (unlike portly Bill Conrad), Mohr made the big breakthrough in movies.