Yes, this is the right answer, although I would correct the numbers a bit.
If we look only at the audio bandwidth, AM stations are limited to 5 kHz of audio spectrum. The 10 kHz figure comes from the fact that AM is double sideband modulation (as opposed to single sideband as used in ham radio and other radio services). So the broadcast signal uses twice the bandwidth of the audio.
FM stations have 15 kHz of audio bandwidth, three times that of AM. They are able to do this because they transmit at a much higher frequency.
The 200 kHz figure includes other things like stereo (two channels of audio), subcarriers for RDS data and such, and the "Carson bandwidth rule" that 'basementcat' mentioned.
I am surprised that the article overlooked this simple and obvious explanation.
If we look only at the audio bandwidth, AM stations are limited to 5 kHz of audio spectrum. The 10 kHz figure comes from the fact that AM is double sideband modulation (as opposed to single sideband as used in ham radio and other radio services). So the broadcast signal uses twice the bandwidth of the audio.
FM stations have 15 kHz of audio bandwidth, three times that of AM. They are able to do this because they transmit at a much higher frequency.
The 200 kHz figure includes other things like stereo (two channels of audio), subcarriers for RDS data and such, and the "Carson bandwidth rule" that 'basementcat' mentioned.
I am surprised that the article overlooked this simple and obvious explanation.