A controversial bill that would require all new cars to be fitted with AM radios looks set to become a law in the near future. Yesterday, Senator Edward Markey (D-Mass) revealed that the “AM Radio for Every Vehicle Act” now has the support of 60 US Senators, as well as 246 co-sponsors in the House of Representatives, making its passage an almost sure thing. Should that happen, the National Highway Traffic Safety Administration would be required to ensure that all new cars sold in the US had AM radios at no extra cost.
I don’t think I’ve ever heard an AM transmission in my life, is there a benefit relative to FM or digital radio?
I think the longer wavelengths of AM transmissions travel a lot farther, and are less prone to scattering, but that’s about it. FM allows for more information density (you can broadcast in stereo, for example), and is less prone to the static that plagues AM radio. That’s why AM is mostly talk stations, and FM tends to be mostly music.
In emergency situations the benefit is range. You can broadcast further and reach more areas with one station.
AM stations have to cut their power to like 10% (often even less!) at night, it’s wild
https://www.fcc.gov/media/radio/am-stations-at-night
Range is the biggest. KMOX in St Louis was known to reach Colorado from my understanding. There are/were a lot of Cardinal fans because of it in that area before they got the Rockies. I don’t think they broadcast as strong now, not sure. FM will cut out in under 75 miles* unless you have a “good” antenna.
*Not sure the proper range.
And at night the way the signals bounce they can be heard for a thousand miles or more. Due to interference only some stations can run full power at night while most have to turn off or turn power way way down.
Occasionally it can be heard across continents even
The AM band is the strongest of the two. Some countries however have made AM illegal to use in consumer vehicles, because it is used by military and state.