As radio station transmitters go, [Mr. Carlson]’s Gates ... wirewound resistors the size of paper towel tubes, and five enormous, glowing vacuum tubes. It’s a pretty neat bit of broadcasting ...

It’s one of the slides shared in a guided video tour of the transmitter’s hardware. The radio station — whose call ... distilled water to and from the tubes to handle the heat dissipation.

North America has long resisted modernization of broadcast radio to newer all-digital systems. This latest AM legislation is ...