Tag Archives :frequency

Some novice crew members have some doubts about the frequency of marine VHF radio. This article gives a brief explanation of the frequency of marine VHF radio.  ...

Distress alerts may be transmitted as a single frequency or a multi-frequency call attempt preceded by a dot pattern. MF/HF equipment should be capable of using both single and multi-frequency call attempts. Where a distress alert attempt contains more than one consecutive distress alert on the same frequency, these consecutive alerts should be transmitted with no gap between the end of one call and the start of the dot pattern of the following call to enable bit synchronization to be maintained  ...

There is no "distance" index in radio communication, because the ultra short wave communication is line of sight transmission, and the signal is blocked and interfered by buildings, hills, forests, electromagnetic fields, etc.,  ...

The principle of intercom communication is to use electromagnetic wave to transmit information in the air. According to Maxwell's electromagnetic field theory, the changing electric field produces the changing magnetic field, and the changing magnetic field produces the changing electric field.  ...

What is AIS? AIS is an important maritime navigation safety communications system intended to limit maritime accidents by automatically broadcasting and exchanging marine vessel information – including a vessel's identity, type, position, course, speed, navigational status, and other safety-related information – between and among AIS-equipped shore stations, aircraft, and other vessels.  ...