G4AZB 's Amateur Radio Website

Homeplug power line adapter/BT Vision Comtrend type network adapter interference, which appeared yesterday evening in a house in an adjacent street. The amateur radio bands seem to be notched EXCEPT for 12 metres( 24.890-24.990 mhz) which is particularly annoying since I have just invested in a beam antenna for this band. The broadcast bands, along with the aeronautical, maritime and other service frequencies, are obliterated, with no discernable attempt at protecting those services having been made. When idling, the sound is identical to the original BT Vision Comtrend devices, a regular high pitched whine, within the range of 22-27 mhz.. This leads me to suspect a BT Vision installation with BT's touted 'new' adapters. When carrying data, the result is a huge increase in levels and bandwidth. The entire HF spectrum from around 3 to 30+ mhz is rendered unusable. As you can see from the signal meter, this is totally destructive, and not just a minor annoyance. I am in the process of tracing the source, and a complaint has been made with the new regulator, the BBC. Since the BBC's own transmissions are affected, I would hope they act swiftly. It's time to recognise that this recent RF "technology" will never be able to coexist with radio users, and compel the makers to ensure their products comply with legally permitted emission levels. Even more so, now they've begun intruding on VHF, including the FM broadcast band.