John Schneider, Jan 27, 2020
With AM improvement on the radars of broadcasters and the FCC, there has been renewed talk in recent years about the subject of AM "boosters," the carrier frequency synchronization of multiple transmitters. The commission opened a comment period on AM boosters in 2017.
t wasn't the first time the FCC has explored this topic and failed to act on it. In fact, AM boosters have been proposed and tested dozens of times since the early days of radio.
Additional story at Radio World https://tinyurl.com/uj77b8s