This story came from an employee of the Santa Fe Railway who in 1969-1970 was assigned to the "radio shop" in San Bernardino, California-- working mostly on the company radios used for communication in diesel locomotives, cabooses, at dispatching offices, etc. But also....
"...One of my jobs was keeping the PA system in the depot running. This relic probably dated back to the time when the Super Chief was the newest thing on rails. It had four-prong rectifier tubes that were only good for a few months (you have to be an "old hand" in electronics to remember them). One night the PA failed. I replaced the tubes and turned it back on. Usually I would have the ticket agent do the final test, but this time he was busy, so I made sure there were no customers around, stepped on the mike switch and intoned 'Train leaving on Track Five for Anaheim, Azusa and Cuuuuc-amonga!' The agent looked up and said, 'I can't believe you just did that!'"