Power Line Interference - UKQRM meets OFCOM
Power Line Interference - UKQRM meets OFCOM
Representatives of the UKQRM group recently met UK regulator Ofcom to discuss the intereference problems caused by devices that use the mains power supply to deliver video and broadband.
Representing UKQRM, its large membership and supporters was;
Mike Trodd founder member.
Ken Underwood (G3SDW) group moderator and policy group member.
Richard Yarnall (M0SNR) policy group member very active supporter
Clive Corrie (investigations and policy manager)
Paul Mercer (Head of spectrum investigations)
Paul Jarvis (Head of business radio, spectrum policy group, also represents marine, aeronautical amateur and CB users and emergency services.)
Dave Donachie (Spectrum and international policy team including T-Cam committee)
Read the report at
Power Line Signalling The Death Of HF Radio
UKQRM is a group fighting this radio interference
UKQRM Yahoo Group
How to report PLT / BPL radio interference
I hope action gets taken soon - already Maplin and DABS (two of the biggest suppliers here) are already promoting these things in their catalogues and omitting to mention the possibilty of RFI
But they are pitching the sales towards computer users and not mentioning radio so the situation could get bad very fast
73 de Daithi
Good to see a meeting taking place. I was one of those 70...yes ONLY 70!!???, that complained.
My interference drove me mad, but when i finally found out what it was, which by the way doesn't take much looking up on Google now or Youtube, I was straight on the phone to Ofcom.
I had to fill in an online questionaire, then i got a phone call the next day and explained what the interference was. The call was on a Friday, then by the Monday i had an Ofcom officer ring me to arrange a test of my equipment. We met up and with a few turns of the tuning dial to where the interference was, he was out the door searching for the culprit.
Once found, and by the way it was a Comtrend adapter used by BT, a letter was posted to the persons house and then he would wait for them to contact him to advise what to do next. Within the next few days the adapter was off, and i beleive the Bt Vision was 'hard wired' instead.
So thats my story and now i enjoy clear bands. Click the link below to hear what the noise sounds like.
73 Caine M6MOF
It is interesting to see British regulators saying many of the same things that US regulators say.
Some of those things are correct; merely hearing noise is not harmful interference. Some of those things are somewhat incorrect; the premise that the station must be completely obliterated to constitute harmful inteference is false, IMHO. Would OFCOM accept that as the standard of operation of their office telephone system?
The statistics that there are 500,000 deployed devices and only 70 complaints is pretty misleading. This assumes that everyone who has interference:
o Knows that the noise they are hearing is not normal
o Knows that the noise constitutes a violation of the law
o Knows what the source of the noise is
o Knows that they can report interference
o Knows where to report it
o Chooses to literally make a "federal case" out of their noise and actually
Those are a lot of ifs, and the premise that the lack of interference reports means there is no interference is flawed on its face. Surely regulators must know this as they say the words they say. It should escape no one's attention that the position they are taking on this aspect of the problem is the one that results in the least amount of action required by the regulator.
In the case of the UK reports, BPL modems have been resulting in S9+ noise levels across several MHz of spectrum, 24 hours a day, up to a few hundred meters from the premise in which the modem is installed. Any experienced radio user knows that this will preclude most use of that spectrum within that area. The potential for harmful interference is strong enough that action should be taken on that basis alone.
Any posture that S9+ noise over several MHz and several hundred meters does not constitute a major interference threat is either self-serving or coming from a head buried deeply in the sand.
Ed Hare, W1RFI
Ofcom are taking a reactive rather than a proactive approach. In other words, ducking responsibility and avoiding stress, conflict and thus work.
By the time they get off their idle backsides, the problem could be too large to manage. With just a small amount of effort now they could nip the problem in the bud - but that'd require initiative and effort - not attributes commonly associated civil servants in the UK.
To take a particular point from UKQRM's meeting, Ofcom said that they could do nothing about power line interference because the apparatus did not use wireless telegraphy - it was communication between hard-wired devices. This is NOT TRUE.
If you read the Wireless Telegraphy Act 2006, Section 54 subsection 5 - and I quote "(5) The apparatus which may be specified in the regulations under subsection (1) or (2) is apparatus which generates, or is designed to generate, or is liable to generate fortuitously, electromagnetic energy at frequencies not exceeding 3,000 gigahertz. "
So in other words, if it's an arc welder, a faulty electric motor or a power line communications device, it comes under that auspices of the WTA.
As I say, Ofcom are shirking their responsibility.
Last edited by g0oil; 02-03-2009 at 09:57 PM.
Ofcom say there are 500,000 BT Vision Installations in use.
However the fraction of customers actually using the PLTs
The user instructions say to use direct Ethenet if all the
equipment is in the same room,otherwise use the PLTs.
SWLs I would suggest are not the type of people to
complain unless the QRM is severe,find the prospect of
making an official complaint somewhat daunting and are
apprehensive about getting involved in a neighbours
Ofcom as a matter of policy do not reveal details of either
party to each other but the SWL may be known anyway.
The number of complainants given is therefore only the tip of the
Ofcom had 4 sets of PLTs removed to resolve my complaint,
all these neighbours are still enjoying their TV pastime.
UKQRM is to be congratulated on informing all sufferers from this
terrible din on what can be done,sadly RSGB have so far done little
in this regard.
The manufacturers of these devices have, by using the TCF route
to obtaining a CE mark (effectively self certification),put all
HF listeners,PLT users(who buy the units in good faith),
retailers,Ofcom and BT Vision into potential conflict.
I have little sympathy with BT Vision,they have access to EMC
engineers who should know about the "leakage" problems which
are almost inevitable when rf is pumped into house power wires.
Interesting to see Walt talking to a novice licence, he genarally avoids them like the plague.
Originally Posted by G3NYY