24/12/2013 04:57 GMT | Updated 22/02/2014 05:59 GMT

Did You Know Your Christmas Lights Might be Interfering With Your Broadband?

Most households will be lit up with a few Christmas lights this week (or perhaps getting carried away with more than a few), and it also happens to be the time of year when we at thinkbroadband see more people moaning about slow broadband.

You might be surprised to learn that these two facts are no mere coincidence, and slow broadband might not always be the fault of your broadband provider or everyone in your area overloading the connection. All sorts of electronics cause radio interference with WiFi signals, but at this time of year a major culprit is the humble Christmas light.

A single set of flashing Christmas lights is unlikely to affect your ADSL broadband, but get enough of them together and you may find you are causing problems for yourself or your neighbours.

To illustrate this we put together a short demonstration of how you can search for radio interference using a battery powered AM radio. (You can see it here on YouTube:

We are not saying rip out your Christmas lights, but if once you put them up each year you find your broadband is playing up, try giving them a quick check with a radio like we did. If there is lots of interference then it might be time to find a new home for your broadband router or Christmas tree.

Aside from your festive lights, the problem of radio interference is generally much worse in the long winter nights anyway because of the way the ionosphere affects AM radio wave propagation once the sun has set. As well as picking up more radio stations, the associated noise from electrical devices will be worse.

The best way to avoid this is to keep your ADSL router away from other electrical devices; particularly switched mode power supplies (the small power bricks we all use to charge our mobile phones). Another tip is to definitely avoid putting your router behind a LCD or plasma TV.

You can also reduce the amount of noise pickup by removing old unused telephone extensions in the home and ensuring that the telephone wiring connecting the router to the telephone line is using twisted pair cable. In an attempt to save maybe 5 pence for every router shipped, suppliers include a cheap RJ11 cable which is flat, and thus picks up noise easily.

Now for most people this is no problem, but if you have drop-out problems it is worth looking at a better RJ11 cable. Ignore the sales buzz about fancy gold-plated cables - a simple round profile cable using twisted pair cable available for less than £5 should help.

Over the years, all sorts of devices that have been known to cause broadband problems. To name but a few, we have LED lights, fluorescent tubes, sparking light switches, welding gear, treadmills and central heating pumps.

Those on a Virgin Media fibre connection should not be affected, but for the millions using a FTTC (Fibre to the Cabinet) connection, you are still using a DSL service, albeit one that uses less copper and higher frequencies. This means that the issue with AM radio should be less pronounced, but spurious noise from electrical devices can still affect you.

Anyone with a fully fibre optic connection, such as Fibre to the Home (FTTH), does not have to worry about the problem at all. Unfortunately there are only around 200,000 to 250,000 homes in the UK that have the option at this time.

As for the rest of us, if you find yourself with a quiet afternoon and an unreliable broadband connection this festive season, why not grab a radio and get hunting?