Understand the range and definition of FM waves, which are frequency modulated, meaning that the FM transmitter alters the space between the waves in order to broadcast sound for radio and TV; FM broadcast waves range from 88 to 108 MHz in frequency.
Learn the difference between the carrier wave and FM harmonics, since FM transmission works by changing the frequency of the carrier wave that broadcasts the sound, and FM harmonic waves are waves that multiply a base frequency wave.
Understand that harmonics are multiples of transmitter frequency, meaning several FM harmonics can exist for a single base frequency.
Define harmonics as even or odd, depending on whether a harmonic is an even or odd multiple of the base frequency; for example, an FM harmonic that is twice the frequency of the base frequency is an even harmonic because two is an even number.
Set the basic frequency as the first harmonic, because multiplying by one only results in the original quantity; then define the higher harmonics by labeling them the number by which they are multiplied, for instance with the second harmonic describing a frequency that is twice as high as the base frequency.
Refer to waves that are factors of a base frequency as subharmonics, using the same rules as FM harmonics, but in reverse; for instance, a frequency that is half the base frequency would be referred to as the second subharmonic.
Create FM harmonics using frequency multipliers, which can transmit a multiplied version of the base frequency that comes from a modulated signal (like an FM transmission); FM harmonic frequencies may be used to transmit sound at a higher or lower frequency to avoid interference from other transmissions.
Block the interferences that FM harmonics may cause cause for other types of FM transmission, such as radio broadcasts, or the quality of reception for TV, pagers and cell phones by using a harmonic filter to block additional FM harmonics outside of the base harmonic range.