October 3, 2013

How AM and FM Radio Are Different

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The current generation of tech obsessed music fanatics knows little beyond FM radio. More and more people are even turning toward alternatives such as HD radio and satellite (sometimes known as XM) radio. However, AM radio still holds clear signals and features a number of programs with a wide and dedicated listener base. But what, exactly, is the difference between AM and FM, and why are some many younger people tuning in to FM?

Let’s begin with scientific terminology. The “M” in both words stands for modulation, or variation in aspects of the electromagnetic frequency being send out over the airwaves. The “A” in AM stands for “amplitude,” which refers to the actual magnitude of the signal being sent out. The “F” in FM stands for “frequency,” referring to the volume of modulations as opposed to their strength.

So, how does that make these two alternatives different? Well, first off, AM is a much simpler technology. You can even build your own back yard AM receiver with about ten dollars of parts. The problem is that this cheaper and simpler technology is also prone to distortion. Distortion can happen because of weather conditions which impact the way that amplitude transmits, distance from transmitters, and other minor factors. AM also broadcasts on “one channel,” meaning that anything it shoots out will be heard in mono rather than stereo. This means it’s fine for things like newscasts and interviews, but poor for music. However, on the other hand, AM is more powerful because of its use of amplitude, and can be heard at much greater ranges.

FM, on the other hand, offers a broadcast which can’t be heard more than about fifty miles from the transmitter sending it. That’s because the signal itself is based on frequency, which dies out more rapidly over long distances. This radio form is higher quality when you’re in range, doesn’t experience interference from weather conditions, and can broadcast in stereo. While price was once a big factor in choosing AM or FM, the advancement of technology has led to FM radio becoming negligibly more pricey.