Broadband News

BT issues safety notice over Comtrend powerline adapters

BT Vision customers whose television is not located conveniently near to the BT Home Hub will have been given two Comtrend powerline adapters to link the BT Vision set-top box back to the BT Home Hub. Unfortunately a small number of the adapters of one model type have a manufacturing fault which can result in the mounting holding the cover of the adapter becoming brittle and loose, resulting in exposure of potentially live mains components. Thus BT are arranging a swap out of the hardware. In the meantime users are advised NOT to unplug the adapters until such time as the replacement hardware arrives.

Update 8:20pm: BT has been in touch to highlight that it is just the DH10P model that is affected by the fault. This is the model shown in parts 1 and 2 of the updated BT safety notice page.

BT has a page online giving advice to BT Vision users located in the Products and Services. For people with the adapters who are concerned that they have not received a replacement pair already, a telephone support number is given on the page.

While BT will have little trouble contacting its many BT Vision customers, sites like E-Bay have been doing a thriving trade in people selling on the Comtrend adapters, so there may be many thousands of these adapters in households for whom BT has no way of contacting them. We could see no sign of a general recall by Comtrend, but we think in the UK BT Vision is the main seller of the devices. For those who have purchased adapters second-hand, then it would be wise to read the safety notice, and consider replacing the adapters with another brand to avoid the dangers of a mains shock, alternatively consider running an Ethernet cable to replace the adapters. Solwise and Devolo are two alternative suppliers of powerline adapters.

Comments

BT not havin a good week are they?

  • cyberdoyle
  • over 7 years ago

You mean comtrend. BT don't make the adapters

  • GMAN99
  • over 7 years ago

They don't, but they're the biggest supplier an warranty/recall issues lie with them GMAN.

I've 6 adapters, a variety of models..wonder where us ebayers stand?

  • MrMot
  • over 7 years ago

Sure its their duty to inform their customers of the equipment they have supplied. I doubt eBayers have any chance at getting them replaced as the original owners will get the replacements (if required)

  • GMAN99
  • over 7 years ago

@GMAN - no they don't, but cyberdoyle is referring to the fact that's BT that's having to replace them all at their expense.

  • nmg196
  • over 7 years ago

If you buy a used car from another, the main dealer/agent is still responsible for recalls, if you get my drift.

  • The_Engineer
  • over 7 years ago

nmg, are they though? I would have thought Comtrend would be footing the bill in the end its their faulty equipment.

  • GMAN99
  • over 7 years ago

I have bought some of these direct from BT quite a while ago. I wonder if they will send replacements ?

  • broadbandmac
  • over 7 years ago

UK law is pretty clear. The contract is between the buyer and the seller. A good manufacturer will offer a replacement but they don't have to.

  • AndrueC
  • over 7 years ago

BT buy in the cheapest rubbish they can find to distribute. Quite apart from the tops falling of these powerline adapters, EXACTLY the same as they did for the HomeHub2 power supply, these nasty things don't even keep within the legal emission limit for unwanted harmonics.

  • m0aur
  • over 7 years ago

http://www.rsgb.org/plt/docs/ofcom_letter.pdf

  • m0aur
  • over 7 years ago

I think most homeplugs are the same in terms of interference. Radiohams hate them.

  • GMAN99
  • over 7 years ago

Yes, hams hate them, but the interference radiated by them, can raise the noise level on your network and drastically reduce your line profile, so web user should hate them also. None are perfect, but the Comtrend are by far the worst.
http://www.rsgb.org/news/pdf/letter_to_rtb.pdf

  • m0aur
  • over 7 years ago

Really...it is a proven fact that powerline devices radiate and cause problems for ADSL and ADSL2+ services?

If that were the case, one would expect users to be reporting speed problems.

  • andrew
  • thinkbroadband staff
  • over 7 years ago

Please yourself. A look at the graphs on the links above, will show unacceptable levels of broadband emissions right across MW and HF spectrum, radiated many metres from the mains wiring. The very same frequencies, that in the evenings can sneak into your extension wiring and nobble your router speed.
Even users that realise their line speed is poor, I would imagine very few have any idea of the cause

  • m0aur
  • over 7 years ago

If you have a receiver that goes up to Wi-Fi frequencies, this is what you would hear being transmitted from your mains wiring via an out of spec HomePlug.
http://www.worlddxclub.org.uk/WDXC_UKQRM_25600-25700kHz.mp3

  • m0aur
  • over 7 years ago

Well, I have a pair of the White (on the right = PG-902) adapters, and can't fault them at all! The black one looks really desirable, and will get that one to extend my home network to the new cabin!
As for performance: far outpaces the WiFi, certainly no impact on line speed - I have 20mb cable ;)

  • n3tm4n
  • over 7 years ago

Oh I've no problem believing the noise they make, on the very rare occasion I use mine for a big file transfer I have to move my wireless mouse receiver much closer to the mouse as the plug drowns it out.

  • GMAN99
  • over 7 years ago

For certain, BT's contract with Comtrend will see Comtrend paying for the recall.

Note - the Comtrend products are NOT HomePlug products, they are "UPA".
The UPA is an organisation with a secret chipset specification supported by a Spanish chipset company that went into administration earlier this year...
The HomePlug Alliance is an industry alliance with big roster of members, which issued the HomePlug AV chipset specification - an open one, with several chipset manufacturers working on compliant/interoperable products.

  • bought
  • over 7 years ago

Solwise, Devolo, Simpler Networks, are HomePlug AV products which don't have the severe radiated noise issues of BT/Comtrend products - even radio amateurs agree on this.
HomePlug products are used by France Telecom, Deutsche Telekom, Telecom Italia, Austria Telekom, Belgacom, KPN, Swisscom, Telia Sonera, Eircom, AT&T, Qwest, Bell Canada, Korea Telecom, SingTel, Chungwa Telecom, PCCW, KDDI, NTT, and dozens of other xDSL broadband providers worldwide.
UPA products are used by BT. They were used by Telefonica and Portugal Telecom, but both stopped after problems.
BT made the wrong choice.

  • bought
  • over 7 years ago

For radio hams they sure did, I'm sure the users themselves aren't really bothered apart from the shoddy build and recall of course ;o)

  • GMAN99
  • over 7 years ago

There are also many HomePlug compliant devices that have caused interference, and none as far as I know can meet EMC requirements when put under test. They are basically a bad idea. Let's hope the high power versions where an ISP shoves it down the three phase in the street can be stopped.
http://www.netgear.co.uk/xe103_recall.php
http://www.bbc.co.uk/rd/pubs/whp/whp-pdf-files/WHP114.pdf
http://www.southgatearc.org/news/february2009/new_plt_interference_videos.htm

  • m0aur
  • over 7 years ago

For those that think HomePlugs cannot raise the level of phone-line noise and lower bandwidth, scroll down to the HomePlug section here.
http://www.audioholics.com/education/cables/alternatives-for-av-home-networking/homepna-moca-homeplug

  • m0aur
  • over 7 years ago

I saw a news article some months ago about homeplugs, the things the have the potential to interfere with are not just your adsl and ham radio, but even broadcast radio and aviation frequencies,mains ac and adsl not a good mix, the more that separates the 2 the better, i would not use them,

  • tommy45
  • over 7 years ago

@bought: ds2 went bust? Excellent. A little while ago, the only relevant silicon vendors were ds2 and someone whose name I've forgotten, is that still the situation?

wrt "users aren't really bothered": putting to one side the potential for interference with other legitimate licenced services: if users are not bothered right now, they will be if VDSL or similar ever comes their way.

BT's remaining DSL techies know there's a problem here but (obviously) are over-ruled by the much higher profile BT Vision folks.

  • c_j_
  • over 7 years ago

Coming to a street near you!
http://www.pcw.co.uk/personal-computer-world/features/2045894/power-line-telecoms-mains

  • m0aur
  • over 7 years ago

The article is 6yrs old?

  • GMAN99
  • over 7 years ago

m0aur, is there much point posting a 2004 article, one which fails to mention the UK's only semi-serious (but ultimately failed) attempt at PLT?

Back in 2004, Keith Maclean, one-time powerline leader of SSE Telecom, was probably still blathering on about their imminent "full commercial rollout" in Winchester and elsewhere (2003 interview URL below).

But just like SSE's "full commercial rollout" of PLT in Scotland, it didnae happen. The economics of PLT made even less sense than the technology. Has that changed?

http://www.ispreview.co.uk/articles/power/

  • c_j_
  • over 7 years ago

PLT in my most recent post obviously not meaning domestic PLT but "last mile" PLT. Sorry for any ambiguity.

  • c_j_
  • over 7 years ago

Bad news in 2004, bad news in 2010. Even good old Belkin are keeping up the bad work of interfering with broadcast radio and broadband networks to name just two, so nothing has changed.
http://plt.g7cnf.me.uk/belkin.htm

  • m0aur
  • over 7 years ago

The state of play now, is that as well as causing havoc across HF, they are now interfering with Band 2 FM, Marine Band and DAB. {Poor old DAB comes off worst, as being digital, it is perfect signal or nothing.
http://www.youtube.com/watch?v=z3yVu5IfaEY&feature=player_embedded
So there we are, 2010 and progress!

  • m0aur
  • over 7 years ago

HomePlug AV technology is endorsed by the American Radio Relay League (ARRL), the largest amateur radio organisation in the US.

DS2 went into administration, something of what they were doing was bought by Marvell.

Belkin use a chipset from Gigle for the "1Gb" product - some of the same engineers as DS2 (and some of the same mistakes with their non HomePlug, proprietary, extension).

  • bought
  • over 7 years ago

"HomePlug AV technology is endorsed by the American Radio Relay League (ARRL),"

Authoritative (ideally ARRL) link please (Wikipedia is only authoritative if it clearly quotes an authoritative source).

The only authoritative-looking ARRL/Homeplug stuff I can quickly find dates back even further than m0aur's article (e.g. to 2000) therefore clearly pre-dates Homeplug AV so isn't really relevant to a standard that claims to have many times the bandwidth. Bandwidth don't come for free.

  • c_j_
  • over 7 years ago

So.. It seems to me, that if all companies followed the example of BT, by issuing cheap 'wall warts' that fell to pieces and exposed the mains, we could open many more cans of worms!

I think the Belkin shows why there is no new information to be found regarding Homeplugs. Quite simply, you will not stop an unshielded resonant length radiator from radiating.

  • m0aur
  • over 7 years ago

I'd be lost without my 3 Develo's delivering completely reliable Internet throughout the house. They certainly have not affected the performance of my router which connects to ADSL 2+ Annex M, nor my father's Virgin cable.

  • bosie
  • over 7 years ago

Yes, users can adopt an 'I'm alright Jack attitude' as it's usually others that are affected. Having said that, all appliances must comply with EMC law, and any that radiate RF must be type approved. I certainly wouldn't want to be in the legal cul-de-sac of interfering with a neighbours protected Band 2 FM or DAB service.

  • m0aur
  • over 7 years ago

@bosie
Have you checked out FM or DAB radio in your house while passing data with your HomePlugs?
These devices actually transmit on a wide band of frequencies on unshielded mains wiring which acts as an antenna, so interference cannot be avoided.
UK mains is delivered via street three phase, with each phase looping to every third property, so radiated RF apart, and subject to proximity, your data transmissions could easily be piped straight into a neighbouring property.

  • m0aur
  • over 7 years ago

So if somewhere like John Lewis sells them it's surely reasonable to assume they are approved etc.?

  • Somerset
  • over 7 years ago

"if somewhere like John Lewis sells them it's surely reasonable to assume they are approved etc.? "

Sort of. CE marking and the like, when properly applied, means the middleman (in this case John Lewis) does not need to be expert in the details of the technologies of the product in question.

Whether CE marking actually is properly applied nowadays or actually worth tuppence is a separate question. It could have been worth tuppence, but it got lost along the way when the usual suspects took control.

If CE marking was properly used as intended, these gadgets wouldn't be on sale.

  • c_j_
  • over 7 years ago

I'm afraid I have no use for FM or DAB m0aur so I guess that puts me in the "I'm alright Jack" camp. The radio stations I listen to are available on the Internet. Even before home plugs came about, radio over the airways has always been a hit & miss experience for me so having it available on the Internet was an big improvement. The ability to schedule recording is another bonus.

  • bosie
  • over 7 years ago

CE marking is sometimes no more than a sticker stuck on in China.
EMC is a two way thing. It is supposed to ensure that all devices can operate without causing interference to, or being interfered with by other devices.
c_j_ is correct, in that if CE marking was properly implemented, these devices would be outlawed.

  • m0aur
  • over 7 years ago

All electronic devices produce a detectable signal. CE marking and EMC law is about keeping those signals suitably attenuated.
HomePlug units are notched (filtered) at spot Amateur frequencies, but still hams are badly effected. Users of other frequencies fare much worse, but if Homeplugs were notched across their total bandwidth, they would be useless.

  • m0aur
  • over 7 years ago

@bosie
Like you, we enjoy Internet Radio on our Wi-Fi radios, with just the local BBC station listened to in the mornings on a conventional radio.

  • m0aur
  • over 7 years ago

"all devices can operate without causing interference to, or being interfered with by other devices."

You'd probably be better to say "unreasonable interference" or similar. Lots of things cause interference, sometimes unavoidably. E.g. don't try to use a radio near an arc welder. Fortunately there aren't too many of them around.

PLT widgets are a different kettle of fish.

There are very few informed folks outside of the powerline vendors themselves that would argue that powerline networking is "reasonable" in its (ab)use of RF spectrum.

  • c_j_
  • over 7 years ago

Meh. I gave up on Belkin after they started selling TOSLINK cables with gold plated connectors.

  • AndrueC
  • over 7 years ago

m0aur wrote: "For those that think HomePlugs cannot raise the level of phone-line noise and lower bandwidth, scroll down to the HomePlug section here (AudioHolics link)"

I smell FUD I'm afraid m0aur - there's nothing in that article (or any other that you've posted) that confirms (or even suggests) that HomePlug adapters reduce broadband connection speed.

Appreciate that you have other reasons to dislike HomePlug, but I'm taking the ADSL speed one with a pinch of salt unless you have something authoritative on the subject?

<continued below>

Cheers, Ben

  • psdie
  • over 7 years ago

@m0aur: OK; this talks about Repetitive Electrical Impulse Noise (REIN) affecting ADSL speed, but says it's far from specific to powerline adapters - it lists PSUs, security systems, christmas lights (!) and set top boxes as common culprits (powerline adapters aren't mentioned specifically).

http://www.kitz.co.uk/adsl/rein.htm

Cheers, Ben

  • psdie
  • over 7 years ago

@psdie
Let's get one thing straight. I have NO "other reasons" to dislike HomePlugs. I have nobody near using them and interfering with me, and I certainly would not spend £50-£60 on a pair to get a signal to a laptop when a cheap dongle will do a better job.
As for "FUD", I have no uncertainty or doubt whatsoever as to what these nasty things are, so I suggest you get your sense of smell checked out. Nobody has claimed HomePlugs are specifically responsible for affecting ADSL speed.

  • m0aur
  • over 7 years ago

From the same Kitz's page: "noisy electrical appliance with a long length of wire which acts as an antennae." To me, that sounds like a description of a typical powerline device. In the case of most of the items on the list, excess RF noise is a byproduct of poor design. With PLT, excess RF noise is fundamental to the design.

Look more closely. Who do the usual UK acknowledged experts on REIN work for? BT. Who is currently the UK's biggeest supplier of PLT kit? BT. Who's got most to lose if PLT kit is banned? BT.

See a potential issue there?

  • c_j_
  • over 7 years ago

"Please yourself. A look at the graphs on the links above, will show unacceptable levels of broadband emissions right across MW and HF spectrum, radiated many metres from the mains wiring. The very same frequencies, that in the evenings can sneak into your extension wiring and nobble your router speed."

So if they are not responsible for affecting ADSL speed, what did you mean by 'nobble your router speed'?

  • andrew
  • thinkbroadband staff
  • over 7 years ago

@andrew
I have not said HomePlugs do "Not" reduce ADSL speed, neither have I said they are solely responsible. I have just said that the MW and HF frequencies they radiate from mains wiring are the same that increase in the evenings and end up as noise on phone lines. I also said that though some may know they have high line noise, and that altering extension wiring may reduce it, very few could identify it. Have you ever hooked up a scope or analyser to a line and identified all the noise sources?

  • m0aur
  • over 7 years ago

My biggest enemies are microwave ovens and phones!
http://img214.imageshack.us/img214/356/scopecopy.jpg

  • m0aur
  • over 7 years ago

I have since moved to Virgin media, But I still use the adapters to link my Son's Xbox to the VM router.
I called BT to ask if they would replace them.
I was told that since I was no longer a BT customer they would need to charge me £70 for a replacement set.
Even tho I paid BT for them, they say the only way they could replace them free would be for me to rejoin BT and take out BT Vision.
I then asked if Comtrend would replace them, and I was told NO.
This cant be right, can it?
I reminded them that I had paid BT for them. But they still say there is nothing they can do for me.

  • abductedcraig
  • over 7 years ago

So did you get them as part of BT Vision and have since ended your BT Vision contract?

  • GMAN99
  • over 7 years ago

@m0aur - in addition to the quote highlighted by Andrew, you also wrote: "Yes, hams hate them, but the interference radiated by them, can raise the noise level on your network and drastically reduce your line profile, so web user should hate them also."

Given the above 2 quotes, how can you possibly say you haven't said that HomePlugs affect ADSL speed?! Nothing wrong with stating it if it's true, but I find your rapid backtracking peculiar! :)

Cont'd ..

  • psdie
  • over 7 years ago

Cont'd ..

@m0aur - I suspect that you have ham radio interests from comments like the following: "HomePlug units are notched (filtered) at spot Amateur frequencies, but still hams are badly effected.", along with your general familiarity with EMC technicalities?

Again, my sympathies to radio hams affected by interference like this - manufacturers should be more responsible. However, FUD isn't on, even when it's for a just cause. I take the same line with charities that think they have a licence to make up stats! ;)

  • psdie
  • over 7 years ago

@psdie
"I suspect that you have ham radio interests" ONLY suspect, when I use a UK callsign as my username, could lead me to suspect you are not the sharpest chisel in the box!
I personally do not use or particularly hate HomePlugs, though I realise their faults.
Possibly I should have said, that it is Amateur Radio operators who proved via test results the faults of HomePlugs, and the RSGB that are forcing Ofcom to do their job properly and apply EMC law, but that would not have given forum anoraks anything to argue over!!

  • m0aur
  • over 7 years ago

Cont'd

@psdie
If you still 'suspect' look up my call on http://www.qrz.com/

  • m0aur
  • over 7 years ago

@GMAN99 I moved from BT once the contract was up, and went to Virgin. And no I paid for the pair after I had vision installed, as I later moved the Vision box after the BT install.

  • abductedcraig
  • over 7 years ago

Hmm in that case craig I'd suggest your right. If they were provided free as part of the Vision contract I'm not sure you'd be entitled but if you purchased them separately I would say you should get a replacement pair.

  • GMAN99
  • over 7 years ago

Ok thanks Gman. I will give them another call and see what they say.

  • abductedcraig
  • over 7 years ago

Just got my replacements, didn't have to contact them or anything they just turned up

  • GMAN99
  • over 7 years ago

Well I get a better transfer rate on these new ones compared to the old ones and they don't seem as noisy either the old ones used to knock out my wireless mouse but these don't

  • GMAN99
  • over 7 years ago

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