- Category: EMC
- Published: Saturday, 07 March 2009 22:45
- Written by Thilo Kootz
- Hits: 15794
The EMC Committee is a permanent committee of IARU Region 1 set up to:
- exchange information related to all aspects of electromagnetic compatibility,
- provide advice on EMC to IARU Member Societies,
- prepare papers on EMC presenting the interests of radio amateurs with respect to EMC
- influence EMC related legislation and standards for the benefit of amateur radio
The EMC Committee Chairman Coordinates the work of the Committee
All Member Societies of IARU Region1 may nominate a member of the EMC Committee.
Over recent years, the focus of the EMC Committee has been on Powerline Communications (PLC). PLC is a technology which can provide broadband Internet connectivity using the mains power wiring supplied to houses. Whilst attractive in that it uses existing infrastructure, PLC has a number of drawbacks as far as users of the radio spectrum are concerned. PLC systems radiate broadband emissions across the HF spectrum 24/7, which can cause severe interference to conventional radio services.
Since EN 50561-1 is in place, European Standerdization requests permanant frequency exclusion of all amateur and aeronautical spectrum on shortwave. Broadcast is protacted partially by a dynamic frequency exclusion, if the broadcast station produces a field strength of 40 dB(µV/m) at the recivers location. If you want to listen to a weaker radio station, you will be disturbed.
However, the current PLC standard is not a solution for everything, bacause there may still be noise in the amtauer spectrum, when intermodulation of PLC signal occur at nonlinearities connected to the main. Examples would be some LED lighting modules or cell phone chargers. In these cases, the notches in the excluded frequency bands are filled up aprtially again.
Members of the IARU Region 1 EMC Committee have been very active for some years representing the interests of the Amateur Radio Service in a number of forums considering the standards that should apply to PLC systems. These forums have included the CEPT SE35 project teanm, the ETSI/CENELEC Joint Working Group and finally the CENELEC TC210 WG11.
For more information on PLC systems, IARU postition papers on PLC, what PLC emissions sound like, and recent developments on PLC emissions and interference, check the EMC papers and links page
IMPORTANT: It is essential that cases of interference to the Amateur Radio Service are highlighted. If you are aware of any such cases, please alert Thilo Kootz, DL9KCE - IARU Region 1, EMC Committee Chairman.