Marine VHF radio refers to the radio frequency range between 156.0 and 174 MHz, inclusive. The "VHF" indicates the very excessive frequency of the range. in the reputable language of the worldwide Telecommunication Union, the band is called the VHF maritime cell band. In some international locations, additional channe...
Marine VHF radio device is set up on all massive ships and most seagoing small craft. it's also used, with barely special law, on rivers and lakes. it's miles used for a huge sort of functions, which includes summoning rescue services and speaking with harbours, locks, bridges and marinas.
A marine VHF set is a combined transmitter and receiver and handiest operates on trendy, international frequencies known as channels. Channel 16 (156.eight MHz) is the worldwide calling and misery channel. Transmission energy levels between 1 and 25 watts, giving a maximum range of up to about 60 nautical miles (111 km) among aerials set up on tall ships and hills, and five nautical miles (nine km; 6 mi) between aerials installed on small boats at sea level. Frequency modulation (FM) is used, with vertical polarization, that means that antennas should be vertical if you want to have right reception.
current-day marine VHF radios provide not most effective primary transmit and receive competencies. completely mounted marine VHF radios on seagoing vessels are required to have certification of some degree of "virtual Selective Calling" (DSC) capability, to allow a misery signal to be sent with a unmarried button press.
Marine VHF on the whole makes use of "simplex" transmission, in which verbal exchange can simplest take location in a single route at a time. A transmit button on the set or microphone determines whether or not it's miles operating as a transmitter or a receiver. some channels, however, are "duplex" transmission channels in which verbal exchange can take place in both instructions simultaneously when the equipment on each ends permit it (complete duplex), in any other case "semi-duplex" is used. every duplex channel has two frequency assignments. Duplex channels may be used to area calls on the public phone machine for a fee thru a marine operator. when complete duplex is used, the decision is much like one the usage of a cellular smartphone or landline. while semi-duplex is used, voice is best carried one manner at a time and the party on the boat should press the transmit button only when speakme. This facility remains available in some areas, though its use has in large part died out with the arrival of cellular and satellite tv for pc telephones. Marine VHF radios can also receive climate radio declares, wherein they're to be had