AM or FM? Shortwave nostalgia like a WW2 broadcast?
Will it be played on a 5.1 DVD?
For a WW2 era play we did the "Phone" preset and added some real shortwave
background noise at about 12 dB lower than the dialog. Static, ocs shift (whistles),
buzz, etc.
5.1 DVD - if radio is off to the side of shot, pan it to the side.