Icom M802 User Manual page 9

UNDERSTANDING YOUR SSB CHANNELS AND
FREQUENCIES
By Gordon West, CMET
Of the nearly 1000 SSB channels pre-stored in your SSB radio, only a
hundred or so can actually lead to meaningful reception. Those "hot
100" channels are likely pre-loaded in user programmable memory
(UPM), and Gordo explains how to dial in these most-important
frequencies....
NAVIGATING YOUR SSB
Your marine single sideband transceiver (transmitter and receiver
combined in one unit) operates on frequencies in the shortwave
spectrum between 2 MHz and 26 MHz. These short wavelength
frequencies refract radio signals off the ionosphere, reflect off sea
water, and may easily skip hundreds and thousands of miles around
the earth.
Marine single sideband channels and frequencies are managed by the
International Telecommunications Union (ITU). Included among these
are all the emergency distress channels for the Global Maritime
Distress Safety System (GMDSS). ITU's stewardship of these channels
ensures that a marine SSB radio purchased anywhere in the world will
have the same international safety and distress channels as all other
SSB's. As a result, all SSB radios can be used anywhere in the world,
from the Med, the Caribbean, or the South Seas to the Bering Strait.
9