Complex sentence: He worked as an engineer and sometime broadcaster for a national Sports Radio network and a privately owned Alternative Rock Station (KEDG) doing late night broadcasting, where he would occasionally fill in on-air.
Split into simpler sentences: He worked as an engineer and sometime broadcaster at a local radio station for a national Sports Radio network. He also worked as an engineer at a privately-owned radio station, KEDG, an Alternative Rock Station doing late night broadcasting, where he would occasionally fill in on-air.