No, not foreign exchange trading – FM Xlators [translators]
Originally, a translator was a lower power transmitter whose intent was to distribute programming in a small area from a primary station, either in an area with bad signals like in the middle of mountains, or programming for non-commercial radio – like statewide NPR networks and satellite fed religious broadcasters. One key requirement for FM translators is that they may not originate their own programming, other than the provision for non-commercial stations to have brief sponsorship messages that are specific to each translator.
Then a very important thing happened – the FCC decided that it was appropriate for an FM translator to retransmit the signal from an AM radio station. This is particularly useful for legacy AM stations in small markets, which previously had to turn off their transmitter when the sun set, or at least lower the power to not interfere with the clear channel AM stations in distant markets.
The results must have been so good that FCC chairman Ajit Pai decided to make this a really big thing – strongly encouraging AM stations to apply. It was believed that adding an FM translator would “save AM radio” stations they were teetering on the brink of going under financially.
Initially, the rules were relaxed to allow existing FX translators (mostly owned by satellite delivered religious broadcasters) to move a significant distance if they were sold between owners. It became apparent that there was much more demand for this than there were available translators, so there was a series of opportunities for AM radio stations to apply for a new license. If granted, the FX license would be married to the AM station for 3 years to prevent a lucrative resale market.
They started with the small-market stations and then worked their way up. Major markets were more difficult, because you had potential to interfere with the full power stations already there. In response, the interference rules were relaxed, and when station owners started filing fallacious complaints from people not even in their protected contour, the FCC largely shut down the complaint process.
In the United States, as of June 2019, there are 4,609 licensed AM stations. There are currently 2,524 FX translators whose programming is coming from an AM station, which is a staggering revolution.
The Call Sign of an FX license is a K or W, followed by a 3 digit channel number, followed by two letters – for example K235AG. Nobody is going to remember that, so many AM stations rebrand themselves as FM 103.5, without mentioning the AM or FX callsign, except during the legal station ID just before the top of the hour. Much of the world already doesn’t use call signs.