FM radio stations all transmit in a band between 88 megahertz (millions of cycles per second) and 108 megahertz. The band is divided into 100 channels, each 200 kHz (0.2 MHz) wide. The center frequency is located at 1/2 the bandwidth of the FM Channel, or 100 kHz (0.1 MHz) up from the lower end of the channel. For example, the center frequency for Channel 201 (the first FM channel) is 88.0 MHz + 0.1 MHz = 88.1 MHz. So there can be a station at 88.1 megahertz, 88.3 megahertz, 88.5 megahertz, and so on. The 200-kilohertz spacing, and the fact that they center on odd numbers is completely arbitrary and was decided by the FCC. In Europe, the FM stations are spaced 100 kilohertz apart instead of 200 kilohertz apart, and they can end on even or odd numbers.
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