We had the opportunity to experience these delightful devices first hand last year thanks to a member of the UKQRM Yahoo group who kindly loaned me a pair of Comtrend adaptors for a club evening. The struggle continues and a reminder to remain vigilant is, I feel, in order. These devices are still being pushed by BT and several high street retailers. They are still causing harmful interference. They are still being sold bearing a CE mark despite the fact that they fail to meet the essential requirements of the EMC directive. OFCOM are, however, responding quickly, positively and free of charge to reports of interference from these devices despite remaining in denial of their illegal status. My personal view is that the higher the number of complaints received the more weight our arguments against them carry.
So, be on your guard against any new sources of interference. Remember the following points:
- The interference is most noticeable if you listen in AM mode.
- Have a listen outside the amateur bands too. Most of these devices notch the amateur bands to a lower level and whilst they can still interfere, it will be easier to pinpoint the source using the higher level out of band. We are entitled to listen to the short wave broadcast bands too!
- If you find something, repeat your measurements with your house powered down to ensure it’s not locally generated.
- If you still find harmful interference report it to OFCOM. Your report will be treated in confidence and the chances are it will result in the offending adaptors being removed by BT.
- Read the current UKQRM government petition and add your name to it if you agree: http://petitions.number10.gov.uk/SaveShortwave2
Early in 2009 the RSGB could have been accused, at best, of keeping its’ cards close to its’ chest on the matter of PLA interference. I was pleased to read that they have now written a formal letter of complaint to OFCOM concerning the sale of these devices. Furthermore, OFCOM’s response claimed that, despite having to order the removal of 143 devices in response to interference complaints, mainly from “radio enthusiasts” they had concluded that the devices did not violate the essential requirement of the EMC directive. Problems were due to the way the equipment was “installed and operated”. In other words, they are fine until they are plugged-in. It is encouraging to read that the RSGB are now considering a legal challenge against OFCOM. Let’s hope it goes ahead and achieves the desired result : http://www.rsgb.org/news/pla_dispute_law.php
Stop press: I have now acquired a pair of these devices of my own to use to demonstrate their effects to other amateurs. If you know of a group of amateurs to whom you would like to demonstrate them please contact me and we can arrange something.