a. Radio frequency spectrum use by microwave multichannel radio.
(1) Spectrum. The radio frequency spectrum is very broad. It is used by many radio
frequency (RF) emitting devices other than those radios used in multichannel communications. The
radios used in multichannel communications systems use only a selected portion of the overall RF
spectrum; that ranging from very high frequency (VHF) through ultra high frequency (UHF) up to super
high frequency (SHF).
(2) Frequency range. Each radio operates on a range of frequencies that may overlap or
parallel the frequencies used by another radio. Yet, the radios may not be technically compatible or may
use entirely different modes of propagation. For this reason, it is difficult to confine a particular type of
radio to a distinct RF operating class or to define a radio by its operating frequency. Figure 13 illustrates
the use of the RF spectrum by various radios used in multichannel systems.