EMC

摘要

The ever-increasing use of switch-mode power supplies (SMPSs) is generating growing levels of radio-frequency interference on amateur bands. This month's 'EMC' column includes an example of this. Tyre static is also a cause of interference to automobile LW/MW reception, and engine management systems can be the sources of other interference. Don, G3HVA, has written to comment on the item in February 'EMC' about locating RF interference sources. He emphasises the importance of searching on the highest frequency on which the RFI is audible and of going to a higher frequency as you get closer to the source. This is an important point which is explained in the EMC Committee's six page information sheet, EMC04, Interference to Amateur Radio Reception (see 'Web Search'). Don has also provided an interesting account of his own experience in locating a source of interference a few years ago.