LED lighting interfered with VHF, both speech and DSC

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The Transport Agency has once again found that radio communications can be seriously affected by other equipment fitted on board. This time it was interference from an LED lamp fitted as deck lighting that was so strong that it prevented communication with the coastal radio station, even though the station was well within radio range. The interference was pinpointed with the help of advanced metering equipment, and it was found that a normal bulb had been replaced with an LED lamp in the deck lighting. It probably did not comply with EMC requirements and caused wideband interference, which affected the entire VHF waveband. A source of interference can affect radio communications in different ways. In the best cases it only causes a little crackling, but it can seriously reduce sensitivity without any abnormal noise being heard in the equipment. It should also be noted that interference on board can make radio communications to shore more difficult (such as VTS, JRCC or coastal radio) since the signal received from onshore installations will be weaker the farther out to sea the ship is. Both the Transport Agency and the National Electricity Safety Board have previously stated that some LED light sources can interfere with other equipment, and sales of many of them have been banned. The reason for the ban is that the lamps do not comply with the requirements for electromagnetic compatibility (EMC). The Transport Agency recommends that there is a procedure for detecting and dealing with abnormal interference on board. One way is to check whether the lamps are CE marked. It is the National Electricity Safety Board regulations concerning electromagnetic compatibility (ELECTRICAL SAFETY-FS 2007:1) which must to be complied with. The regulations are based on the EMC directive. Equipment causing interference should be reported to the National Electricity Safety Board.

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