School me on AST
What exactly is AST? My radio has three FM selections: FM1, FM2, FM3-AST.
FM1 and FM2 are simply different collections of presets, right?
But what is this AST business? Why does only the FM3 collection get it?
And if AST is specific to FM3, why then is there a soft-key on the display corresponding to AST for the FM1 and FM2 collections? Does AST apply across the board? Or does AST apply only to FM3? And what is AST?