Table 1-1.—Frequency Bands.

Table 1-1.—Frequency Bands. upper and lower ends of the medium frequency (mf) band. Long-range shipboard communications were con- ducted exclusively in the high-frequency (hf) band, so a large percentage of shipboard transmitters and re- ceivers are designed to operate in this band. On board your command, you may find satellite communica- tions has pushed hf into aback-up role. A significant portion of the very-high-frequency (vhf) band is assigned to the commercial television in- dustry. Some naval uses of the vhf band are mobile communications, repeater operation, navigation, am- phibious and special operations, short range line-of- sight (LOS) communications, and satellite communi- cations. The ultra-high-frequency (uhf) band is used exten- sively by the Navy for LOS and satellite communica- tions. Mobile communications, radar (over 400 MHz), and special operations are some other uses. The super-high-frequency (shf) band is the work- horse of microwave communications. LOS communi- Figure 1-2.—Frequency spectrum. 1-3