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Your view: do LED light bulbs interfere with radios?

Multi-coloured leds

When we looked into the unusual issue of LED light bulbs interfering with DAB radios, we found that the stories were true. So we asked you to share your experiences so we could see how many of you were affected.

We sent a number of cheap, 12V LED bulbs to our lab for testing. And we found that when a digital radio was placed within a few metres of the switched-on bulbs, the signal went fuzzy. Within a few centimetres, the signal cut out altogether.

We asked you if you’d had similar experiences, and 2Dears was one of many who told us they had:

‘In November, we replaced 9 lights in the kitchen with 4.3w MR16 warm white LEDs for use “with an existing Lv transformer”. The DAB radio in the adjoining dining room stopped working immediately the lights were turned on’

We also heard from commenters like George who were having trouble with their FM radios:

‘Our FM kitchen radio gets a hiss over the speech (to the extent that BBC R4, our usual channel, is almost unusable) when the LED spots are on.’

John Dalton has a similar issue:

‘I tried to be green and bought some 12v MR11 LED spots for our kitchen downlighters. Switched them on and Radio 4 went to white noise on the portable VHF FM radio on the kitchen table.’

Shining a light on the problem

David Lewis had a big problem with LED bulbs, but he managed to find a solution:

‘I purchased Ikea lights (6 x 12v halogen bulbs) per 8m run of wires, plus transformer. With the lights on there was no interference of radio reception. I replaced the halogens with 5watt LEDs and replaced the transformer with the appropriate driver.

‘From then on – disaster. Switch one set of lights on and the station would be interrupted by a series of loud plops. Switch two sets of lights on and the tuner would cut out completely. Today, I replaced the indoor aerial with an external five element Triax DAB aerial. Problem solved. Superb reception with any number of LEDs on.’

A number of you experienced problems with electronics other than radios, like Keith:

‘I have two TCP 6W LED GU10 bulbs. The problem I have is when they are switched on and you stand near them, I have a high pitched whistle in my digital hearing aids.’

Tonyp isn’t too hopeful for a resolution, but we liked his metaphor so much, we’ve given him Comment of the Week!

‘There is little scope to make radio receivers less sensitive to this type of interference. The problem is that the lights are radiating energy at the frequency being received. Removing the interfering signal is rather like trying to remove the milk from a white coffee – possible but difficult and rather expensive.’

Looking on the bright side

But we’re pleased to report that a number of commenters, like Graham Pickworth, have had no problems:

‘I have six Aurora brand LED GU10 6watt 3000k non-dimmable light bulbs in my kitchen, purchased from Amazon. There is also a Bose VHF radio within 64 inches of the nearest bulb and I get no interference at all. I also have a Roberts DAB radio which I held up to within about 2 or 3 inches of one of the bulbs. Once again radio reception was perfectly clear.’

Finally, Wavechange had an interesting idea to help shoppers find the right bulbs:

‘LED lamps are expensive and the only way to be sure that interference will not be a problem is to test them in your own home. Perhaps ”bring a bulb” parties could be a new social event to help householders find out which LED lamps to buy.’

Comments
bernie says:
29 March 2013

hi
we put new led bulb in my husband really likes them as for me iam not keen on
them as i like bright light
thanks

The recent Conversation about the problem of interference created by certain LED lamps has highlighted an important issue that prospective purchasers should be aware of. I’m not sure that everyone will understand the helpful technical advice from our experts but Tonyp (see above) expresses the problem in a way that is easy to understand. Essentially, the priority is to prevent generating interference rather than to expect radio manufacturers to try to deal with the problem.

We are beginning to learn that CE marking is of limited value, since both good lamps and bad lamps will carry this label. That is hardly surprising since the manufacturer has declared compliance with standards rather than submitting products for independent testing.

Perhaps it would be useful to have a more general Conversation about low energy lighting. I imagine that many have invested in LED lamps and impressed by the economy but disappointed by the light output. We are still waiting for a replacement for the 100 watt light bulb at a sensible price.

Kevin says:
29 March 2013

I see that most of the above issues which have eminated from changing from incandescent to LED bulbs are when doing so by continuing to use LVT (Low Voltage Transformers). There are two reasons why you should avoid this if possible, firstly is the frequency. The bulbs operated by the LVT will be at a differtnet frequency than the mains voltage (240v) which may be causing the radio interference issues and secondly, it is the cost. 240V replacement LED bulbs are just the same, if not cheaper to buy than LVT’s, but the LVT’s will be more expensive to run as you loose some efficiency through dropping the voltage through mains to 12V tranfomer. Mains replacment bulbs can be purchased to fit in to the existing 12V LVT light fittings (bulb bayonet fitting will also need changing), the only other tasks then is to remove the LVT’s in the electrical line, an easy task for any DIY enthusiast. I replaced 10 X 50 Watt LVT 12V incandescent lights in my kitchen with 10 X 4 Watt 240V LED’s, only about 10 – 15% reduction in the noticable Lumen, but a huge cost saving in consumtion and worth every penny. It is now counter entuative to leave the over head lights on in favour of the cabinet under and over lighting, which consumes 88 watts compared to these lights which now only consume 40 watts instead of 500?

Kevin, all LEDs are current-operated devices at low voltage (e.g. 350mA with a typical forward voltage between 2.6 and 4v DC) – needing to be run at constant current ideally. So a 240v (AC) LED will have a controller to provide this current-controlled DC supply. The issue seems to be the quality of the controller and suppression – like many things, you’ll usually get what you pay for.
I do not see any European / IEC standards published specific to LEDs, controllers and EMC although I have found Drafts for Comment that precede a standard. Standards are not normally legally-enforceable documents but CE marking is essential for free trade within the EU, and this depends upon compliance with standards (with the shortcomings highlighted earlier).

Kevin says:
29 March 2013

The issue is known as EMC (Electro Magnetic Compatibity) and isn’t just restricted to lighting. There are problems with SMPS (Switched Mode Power Supplies) a lot of which are the small chargers we plug into the mains wall sockets. Plasma TV’s, Broadband Routers, PLT (Powerl line Telecommunications) which are plugged into the mains to distribute video etc around the home, Computers etc. The problem is that these electronic products produce RF (Radio Frequency) electromagnetic fields and they can cause issues in other electronic products. The problem is huge.
Check out the following:

http://www.theemcjournal.com this is location for the EMC trade publications which in the Bananna Skins section of the archived EMC journals gives you an idea of the scale of the problem. It makes for very worrying reading over and above lights. Issues arise for the safety of live. You will be horrified by what we have created.

http://www.rsgb.org this is the Radio Society Of Great Britain which represents the Radio Amateurs in the UK, take a look at the PLT info.

I as a Radio Amateur are fully aware of the issues surrounding EMC. Where I live the radio spectrum is now becoming an ‘electronic smog’ which is worsening as each year goes by.

So to sum up. Lights are a problem, but there is much worse out there. What about EMC issues in your modern car. They do exist and have caused fatalities, just read the EMC journals.

I hope the above is of interest.

Phil says:
29 March 2013

It shouldn’t be a surprise. Back in the day when calculators had LED displays if you placed one close to a radio it was almost possible to play tunes on the keyboard.

We should have been better prepared.

I think that most of these lamps use a “Switched Mode” power supply which generates a lot of Radio Frequency Interference!! The cheap ones probably have no built- in shielding to stop this radiation, whereas the better/ more expensive ones have.
It may be possible to report the manufacturers to the appropriate authorities for generating excess interference!!
I am an ex broadcast engineer and have found similar interference problems in the past in my career.

I have four LED Homebase 50/60 H3 6W Warm White bulbs in my kitchen and they create interference on my Roberts DAB radio

Cat says:
3 April 2013

I also have succeeded in destroying DAB radio reception (but not standard FM reception) in our kitchen when we changed our 12V halogen downlighters for MR16 LED NxtGen Series II Non-Dimmable bulbs and changed the transformer for an Aurora 16w LED Driver / Transformer ( AU-LED16T) – the response from SIMPLYLED was “This is a very rare problem, as it only occurs in a very small number of cases. I’m afraid there is nothing I can suggest as a resolution to the problem. Our manufacturer are aware of this and are working to solve it.You are more than welcome to return any of the products to us for a full refund”. I wasn’t sure if it was the transformer or the LEDs that were the problem. It seems a shame that being energy efficient has this consequence. Is there any evidence that ‘cheap’ bulbs are worse than expensive ones?

Dillydally says:
5 May 2013

We have just replaced the halogen lights in our kitchen with LED from LED hut. firstly, some of the bulbs will not go in properly to the existing fittings! BUT worse the DAB radio sounds awful, a waffling underwater sound, only in the kitchen the one in the office and bedroom OK, I tried with battery so not mains, I am wondering wether to get an outside aerial? It was a big investment, £108.00. We have not replaced the drivers, transformers, or whatever they are called, unwilling to spend more in case it does not work!.

Gary says:
9 April 2013

This is very interesting.
I would guess that for these LED lights to be sold in Europe they should be CE marked which amongst other things would mean that they should conform to strict radio frequency emissions limits.
LED’s require a low voltage DC (Direct Current) power supply which is generally produced by a “switch-mode” power converter which can generate high frequency radio emissions. The manufacturer should take steps to ensure these emissions are below the required (legal) limit. However, these regulations are generally not well policed and manufacturers can self certify.

It is likely, that the LED lights which are causing the interference do not comply with the EU RF emissions standards and should therefore be reported to the trading standards authorities who should at least check the manufacturers test records. If the manufacturer is outside the EU then the organisation that placed them on the market in Europe is responsible.

Sam Wilberforce says:
16 April 2013

I have 5 LED united super GU10 dimmable LEDs (7W) about 2m from an indoor aerial of a hifi system. The FM reception is unaffected, while the DAB (which is a weak signal where I am) cuts out completely.
I originally bought 7 of the LEDs, and have had to replace all of them as they either started flickering or stopped working altogether. Mr Resistor have suggested that their newer ones which they supplied are from a different manufacturer. I have also changed the dimmer.
Clearly early technology; the warm 3000K light is fine for the kitchen but not for the dining room as they don’t dim enough. Please keep up the pressure to move this potentially brilliant technology on – remember the original Phillips bottle shaped CFLs?

Tim Thornton says:
23 April 2013

I noticed a problem with my Roberts DAB radio after converting my downlights from Halogen to LED. The radio cut out (it was searching for signal) whenever the lights were on (even on a different storey). I solved the problem by replacing the transformer for an LED driver.

It is becoming evident that some people are assuming or being told that low voltage LED lamps are a direct replacement for halogen bulbs, which can result in radio interference. Another problem is that dimmers intended for incandescent lighting are being used for LED lamps, which can result in unsatisfactory operation or failure.

I believe that it is important that retailers should do their best to help customers use products correctly and be prepared to provide refunds (including postage where appropriate) if they fail to do so.

Good news on higher efficiency and lumens from LEDs:

http://www.rdmag.com/news/2013/04/cause-led-efficiency-droop-finally-revealed?

Electrician 1 says:
29 April 2013

I have changed the kitchen halogen to high powered led lamps and they are NVC 7watt warm white and when ever these are on they interfere with the radio By making it crackle in the rest of the house I have fitted the other lights with gu10 high power warm white 3 watt from led hut which don’t interfere with the radio but I have had a few of these lamps just stop working so much for there long life

Surely it is not the LED lights that are the problem, it is the power units that drive them. All switched mode power units generate a whole load of EMI if not properly suppressed.
LED lights are low voltage DC devices, and to get the best from them they should be used as such.
It is trying to use them as indevidual mains driven devices that start giving them a bad name. In my view they should ideally be used with a central low voltage power distribution system (12, 24 or 48 volts DC), that means basically re-designing the house and its wiring, and that can never happen until and unless central government or more likely the EU takes steps to bring this about.

If you read the comments, the general consensus is that the mains voltage LED lamps are less of a problem than the 12 volt versions. The problem will be solved by better design.

There is no such thing as a mains LED.
LED’s operate at around 3 volts DC, as I am sure wavechange you are very well aware, as is every other person out there that knows anything at all about semiconductor devices.
With such a comment from someone whom I know knows better there is obviously no point in any further input from me.
Peace and goodbye.

My point is that it is not necessary to run LED lamps at low voltage, since there are already products that do not cause interference problems when run on mains voltage. We need high voltage for high power items such as heaters to avoid the need for heavy wiring. We could use separate low voltage supplies for lighting but that would make for lower efficiency and one of the reasons for using LED lighting is to conserve power.

I believe that there is an advantage in pulsing the DC supply to LEDs, presumably because this produces more light or less heat. That is why even battery-operated LED lamps can create interference. It really is all about good design. I hope this justifies my comment.

Dillydally says:
14 May 2013

I came on this site earlier, asking why my DAB would not work with my new LED lightbulbs, after reading all the replies and advice I phoned a friendly electrician who advised me to have the lights converted to mains,(No transformers) He quoted a very reasonable price for this and so we went ahead, having had either a transformer or a bulb going down at least once a week and had spent a fortune in the previous 8years. the basic halogen lights came with the new fittings, but he supplied 3 extra led to try out. and Lo, they worked even with the radio right next to them, BUT, we do not actually like the LED light and so are keeping the halogen at least in the main working area The manufacturer has refunded the LED bulbs so all good in the end and maybe the GU fitting bulbs will last longer.

I asked the Lighting Industry Association (the UK trade association for lighting amd lamp suppliers / manufacturers) for their knowledge on this and have just received the following reply;

“We are aware of reports of interference of LED lamps with dab radio and some TV signals. The BBC are the organisation charged with investigating such complaints and we made contact with them over 2 years ago to ask that any reports are also forwarded to us for investigation. To date we have received none. To answer your question EMC standards do apply to LED products and reputable manufacturers will test to the required standards.

We are also aware of an increasing number of cheap imports which fail to comply with the regulations on other counts and to this end the Lighting Industry Association has initiated a market surveillance project in conjunction with the National Measurement Office (the body charged by UK Government with policing a number of EU Directives). This project is already underway and is currently testing over 1000 retrofit LED light bulbs in our own UKAS accredited test laboratory in Telford.

We would of course be keen to receive reports of offending products as part of our activities to remove non-compliant products from the market.”

I will reply with a link to this conversation where they can see some of the offending products. They are clearly receptive to reports of suspect products; I suggest you email them, and Which? could perhaps collaborate with them in exchanging information? They can be contacted through their website – http://www.thelia.org.uk

Alan Telford says:
2 June 2013

I ran into theproblem this weekend. When the lights went on the DAB stopped working. The same circuit worked fine with halogen lights.

I then carried out the following tests

Ran a single LED light from a 12v battery .. No issue
Ran 3 lights from the cable that goes to the transformer again no problem
Ran the radio from the 12v power pack with the lights on mains… significant interference.

I conclude the interference is not coming down the mains but through the air and that it is caused by the combination of the light power supply and the lights.

Dillydally says:
2 June 2013

Having become frustrated by the transformers blowing on our halogen lights plus replacing a bulb at least once a week,so frequently, that we decided to go with led bulbs, and as I posted a few weeks ago, these then interfered with the LED radio, SO we had the light fittings replaced to mains fittings and it will take either led or halogen,(the ones with the stubby fittings) These do not cause interference because there is no transformer, so we have LED in half the kitchen, and halogen over the table, so we can read the paper! Result, everyone happy and LED Hut refunded the 12 LED bulbs.

LED radio?? Most of us are stuck with old fashioned DAB and FM radio. 🙂

Neil Ackerley says:
14 June 2013

A few weeks ago my next door neighbour had a set of SAXBY ROXY LED lights fitted into their kitchen. When they are switched on my radio receivers over the whole of the shortwave spectrum of 3 – 30 MHz are made completely unusable from a very considerable level of RF pollution. I am a fully licensed Radio Amateur of 50 years standing and when the lights are on I am completely wiped out. OFCOM have confirmed that the lights create substantial interference but have so far refused to carry out their duty of keeping down undue interference. They simply say that the devices conform to regulations but that doesn’t alter the fact that the lights create diabolical interference. I would welcome Which coming to hear for themselves the problem. How do I contact Which other than on this thread?