It was a cool November morning, still a couple of hours before sunrise, and downtown Marshall’s main drag was quiet except for the muted din of Florida Georgia Line’s “Cruise” emerging from speakers beneath the white awning in front of KDPM-FM (92.3) “The Depot.” Shortly after the song ended, the Fat Man came slowly walking around the corner and let himself into the three-year-old radio station’s studio.The Fat Man is the nom de deejay of Chip Arledge, the manager and lead host of the Depot, which specializes in country music and, in Arledge’s words, classic rock “that doesn’t piss off country fans.” The station gives extra play to Texas artists, especially those hailing from East Texas. You might hear a Willie-and-Waylon song segue into a…