(2) Since the frequency of a radio wave is very great, it is expressed in kilocycles per second

(kc) or megacycles per second (mc). One kc is equal to 1,000 cycles per second, and 1 mc is equal to

1,000,000 cycles per second.

(3) For practical purposes, the velocity of a radio wave is considered to be constant,

regardless of the frequency or the amplitude of the transmitted wave; therefore, to find the wavelength

when the frequency is known, divide the velocity of the frequency.

(4) To find the frequency when the wavelength is known, divide the velocity by the

wavelength.

c. Frequency bands. Most tactical radio sets operate within the 1.5 mc to 400 mc portion of the

frequency spectrum. Radio frequencies are divided into groups or bands of frequencies for convenience

of study and reference. The frequency bands of the radio spectrum are shown in the following chart.