How long was Stan Chambers at KTLA?
Stan was with KTLA for 63 years, but he doesn't really fit the requirements of this thread, since he was only anchor for short periods. He was mostly a reporter. From Wikipedia:
'His career began shortly after KTLA became the first commercially licensed TV station in the western United States. His April 1949 on-scene 27½-hour report of the unsuccessful attempt to rescue Kathy Fiscus from an abandoned well in San Marino, California prompted the sale of hundreds of TV sets in the Los Angeles area. His report has been recognized as the first live coverage of a breaking news story."