By Dan Lyons He joined the franchise in 2018, a year after leaving ESPN. View the original article to see embedded media. Legendary broadcaster Brent Musburger stepped away from his national sports broadcasting career with ESPN in January 2017, taking on a job as the Raiders radio voice the following summer. After four seasons on the mic for Las Vegas, Musburger appears to be leaving the franchise. “Many thanks to the Raiders organization for fond memories,” he posted to Twitter on Friday morning. “I’ll miss broadcast partner Lincoln Kennedy and the radio production crew. What’s next? I hear M…