AM radio in cars presents an engineering dilemma

MARCH 27, 2024 BY BILL SCHWEBER LEAVE A COMMENT

Design engineers are caught between a push to drop AM radios from cars and the radio industry’s pushback.

It hasn’t received much attention among all the other news (mostly bad, some good), but there’s some momentum in the U.S. Congress to mandate the inclusion of AM radio receivers in cars. Among all the other issues with which Congress is grappling (make your own list here), this may seem like a fairly small issue, but it is not to the key players and has major costs, consequences, and implications.

Who are the players? On one side, it’s the AM radio broadcasters who fear that they will lose a significant fraction of their audience if AM in cars disappears – apparently, that’s a major listening venue for their audience. On the other side, vehicle makers are challenged by the cost and design effort to make AM radio receiver performance acceptable in today’s EMI/RFI-spewing cars, especially electric and hybrid electric vehicles (EV/HEV).

Tesla, Volvo, and BMW are among the companies that have already stopped providing AM receiver functionality in some models; last year, Ford said it would join them but reconsidered and reversed that decision after it got political heat from lawmakers.

There are many interesting, viable, and legitimate arguments made by each side. The arguments for retaining and mandating AM are that it has wide, low-cost reach and is a valuable resource in case of emergencies such as natural disasters. it doesn’t take a lot of infrastructure to maintain links between broadcasts and the listeners. As long as the transmitter is powered up, you can reach and add listeners very easily, and there’s no limit to their number. There’s also the historic, almost nostalgic case that AM radio was the first electronic mass-media technology, so how can we toss it overboard?

{snip}