A marine transceiver is an electronic device that combines the functions of a radio transmitter and radio receiver into one unitary device that is capable of sending and receiving radio communications. The transceiver allows nautical users to transmit and receive radio waves for purposes of communicating over the allotted portion of the radio spectrum designated for use by marine vessels. Marine radio transmissions can occur on the high frequency band or in the very high frequency (VHF) or ultra high frequency (UHF) portion of the electromagnetic radio spectrum.
There are two basic types of marine transceivers. High frequency models are built with the capabilities of transmitting and receiving the high frequency signal range allotted to marine radio transmissions. These transceivers are able to transmit over long distances and are favored by mariners whose nautical travels take them far from shore. Other models that are stand-alone VHF or UHF transceivers are for short range communications. Some companies manufacture models that combine high frequency as well as VHF and UHF capabilities in one all-purpose model.
A marine transceiver contains digital circuitry that facilitates both transmitting and receiving radio signals. Desired frequencies for both sending and accepting messages can be easily entered into a digital numeric keypad. The frequency readout is viewed through a liquid crystal display.
Modern nautical transceivers can be digitally tuned to specific frequencies and come with multiple memory channels for storing different frequencies. Marine transceivers are manufactured in various configurations. Some models come with pre-designated channels or memories that are already tuned to various frequencies commonly used in marine radio transmissions. A user can select or recall the various channels or frequencies by means of a push-button numeric keypad. Other models allow users to manually tune desired frequencies with a rotary, digitally-synthesized dial that displays the chosen frequency in a digital format in the liquid crystal display.
The electronic circuitry of a marine transceiver is highly complex, as it must combine the features and electronic capabilities of both a dedicated transmitter as well as a receiver in one compact unit. For optimum performance, the marine transceiver must be matched with an appropriate antenna used for both transmitting and receiving purposes. Given the space limitations on nautical vessels that preclude the use of external, long-wire or other large antennas, marine transceivers are designed to achieve peak performance when connected to the vertical whip antennas used on most ships.