Yeah, I recall trying that a few years ago. First shot was for a group over on east 5th. Never got through the front door.
Then I put together a killer tape, voices, accents, a lot of variety, and sent it to the woman who several people recommended as the top agent in Austin. I don't think she ever listened to it. She never called. When I called her, she said it sounded "Too Dee-Jay-ish". Sheesh.
So I guess the best strategy is to pass yourself off as an actor, and don't let on that you've ever been inside a radio station.
Then there was the time I needed to look for another job. I contacted this national placement firm. The guy was very excited, told me he had an opening for me in Indianapolis, and to overnight a package. Then he never would return my calls. He did, however, call my program director to tell him he had some great candidates for his upcoming opening. (my job).