The British DX Club

Shortwave interference from Power Line Modems / Adaptors

There is a new and deadly threat to our hobby of Shortwave DXing and Listening and it comes in the form of a little device designed to distibute broadband and television signals through the mains wiring. Severe interference across the shortwave band from 3-30 MHz is the effect of these units known as "Power Line Modems" or "Power Line Adaptors".

One model in particular currently being supplied to BT Vision customers in the UK seems to be causing the most concern. The models in question are usually made by Comtrend - model DH-10PF. The interference, in the form of a high pitched digital noise, has been noted from such devices 24 hours a day over a wide area, often exceeding 100m.

UK QRM videos

See a demonstration of the interference on Youtube

Third video - Know Your Enemy Demonstration of interference from the Comtrend adaptor and how to track down interference.

UKQRM news group

If you are suffering from this interference from a neighbour or are concerned about the issue, we recommend you join UKQRM. The group is campaigning to get these devices withdrawn and also offers advice on how you can get Ofcom and BT to resolve a specific interference complaint. UKQRM Yahoo group

For further information see the UK QRM web site

Sign the Petition!

Sign the Save Shortwave Petition on the Prime Minister's Web Site (UK citizens and UK residents only)

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Updated: 27 Oct 2008