航海英语朗读9

2021-04-01 17:19:2401:37 391

声音简介

Passage 9
A VHF-transceiver (transmitter +receiver) transmits and receives radio signals. The VHF is used to bridge short distances, is easy to operate and is allowed to be used both in territorial waters and inland waterways. Its receiver has a “push-to-talk button”. If the installation is a“simplex” radio, speaking and listening cannot be done simultaneously. When you wish to speak, you push the button; when you wish to listen, you release it. Before changing from
speaking to listening, you say “over”.VHF radio-communication can bridge about 40 miles. MF- or HF radiotelephony is used to bridge 150 miles (MF) to 2000 miles (HF).
Reception of radio signals will not always be of high quality, and coverage will not always extend to the desired areas. This may of course have consequences for the safety of the vessel and her crew. These disadvantages of communication through speech have led to the introduction of Digital Selective Calling in maritime communication.