⟩ Explain me who Were The First Full-time Radio Announcers?
At KDKA it was Harold W. Arlin. He also was the first play by play sports announcer there. The famous Graham MacNamee was the first announcer at WEAF, New York, rivaled at the time by Norman Brokenshire at WJZ.
The First African-American announcer was Jack Cooper on Station WSBC, Chicago, in 1929.
If we want to talk "part time", then we are probably talking about Some of the early people like Doc Herrold, Frank Conrad, or folks from WHA. As far as first female announcer, it was likely Cybil Herrold.