For programmes which are pre-recorded, we create the subtitles in advance. A technician uses the audio and picture to sync them with what’s happening on screen. For a programme broadcast live, (like the News), subtitles will be generated as it is broadcast, which is a complex and problematic process. This means you’ll often notice a delay when watching live programmes.
DAB FAQs
Why am I unable to receive Local Radio, or National Radio such as 鶹Լ Radio Scotland, on my DAB Radio?
The 鶹Լ's local and national radio services are carried on local commercial DAB Multiplexes. Please see our help page to see how DAB multiplexes work, Therefore, you may not be receiving this service, as there is not a commercial DAB service in your local area. To check what coverage of DAB services are available in your locality, please see our Transmitter checker tool.
My DAB reception has started to drop out, is this due to poor reception?
Firstly, poor reception might be down to poor coverage, so it is best to check you are in a DAB coverage area. Use our transmitter tool, which will tell you what national and local DAB services are available in your locality.
Secondly, If you are in a good coverage area, and are still receiving poor DAB reception please try our Problem Assistant for further advice.
How can weather affect DAB reception?
DAB reception is rarely disrupted by high-pressure weather conditions, but under some circumstances, signals from very distant transmitters can cause reception to break up, or be lost for periods of time. If you suspect this - particularly if you are also getting interference on FM - wait until the weather changes.
Can LED Lights Interfere with my DAB Reception?
There is a possibility some LED Lights can cause interference to DAB and FM Radio Reception, particularly if LED lights are used to replace halogen lights, and retain the original transformer. This is because the power used is lower, and is forced to work outside of its normal operating parameters, resulting in electrical impulse interference. For more information on interference, please see our
DAB Help Guides
What is a good DAB installation?
Coverage and location
Your radio must be in a good DAB coverage area to receive 鶹Լ services. Have a look at our Transmitter Checker to see what 鶹Լ services you can receive where you are. If you live in a basement flat, or your building is steel-framed or reinforced concrete, coverage may be affected.
Tuning
Most DAB radios can be tuned easily at the touch of a button. Sometimes a full scan is required. Portable radios should be tuned in a location in your home where the best possible signal is received. Most DAB radios come with built in signal strength meters which can be helpful. From time to time radios should be re-tuned in order to discover new stations.
Telescopic aerials
Telescopic aerials on portable radios should be fully extended to receive a good signal. Tilting and swivelling the aerial will help to get the best signal. Broken aerials may affect reception.
Outdoor aerials
An externally mounted aerial can be attached to many types of DAB portable radio and hi-fi systems. DAB aerials are different from FM or TV aerials, so you need a good quality DAB-specific aerial. An indoor aerial may be good enough, but for the best reception use an outdoor one. Ideally, this should be on the roof or high up on the outside of the building, though it may also give good results in the loft.
Cables and Connectors
If you have an external aerial, a radio signal will always lose some of its strength as it passes along the cable and through the connectors. It is important to minimise the loss by using good quality cable and connectors.
DAB radio in cars
DAB uses different frequencies from FM radio. We advise you check that your antenna is able to receive DAB, in the majority of cases you will need a new antenna. An exception is "helically wound" FM aerials. See our guide on DAB radio in cars
Qualified Installer
The 鶹Լ cannot recommend individual Installers. The ) is a recognised trade body which will can put you in touch with one of their members in your area.
Troubleshooting DAB reception
Transmitter faults
By using our Transmitter Checker, you can check which DAB radio services are available at your location. It will also show you any transmitter faults. Currently it reports on network DAB stations only; Local and Nations radio faults are not included.
Works and Warnings
Check whether there are any known works or warnings that might be causing the problem.
Tuning
DAB uses multiplexes to group services together. The 鶹Լ network stations, e.g. 鶹Լ Radio 1, 鶹Լ Radio 4 are grouped together in a single multiplex. Nations and Local radio services are carried on a mix of commercial multiplexes.
Try switching your radio on and off. If you still have a problem use the ‘autotune' function to re-tune. If this does not work, a full re-scan might be needed. Check your radio manual for specific instructions on doing a full re-scan. Further information on tuning your DAB radio can be found by visiting the site or see our DAB tuning guide.
Portable Radios
Ensure the telescopic/integrated aerial is fully extended. Try moving the radio around to see if you can find a better position where you get good reception of all the stations you want to listen to.
In most circumstances the supplied telescopic aerial should be perfectly adequate, and as a rule of thumb DAB aerials tend to work best when vertical and extended at least 35 cm. If your radio reception is poor then you could consider an external aerial for best reception quality. Even in good areas an external aerial will guarantee optimum performance and will also ensure consistent listening quality.
Many Digital radios have a signal strength display which enables you to position the Radio for the best reception (usually a number of blocks) as a guide of reception quality. Unfortunately, some radios are less sensitive than others and need careful positioning to work reliably. If your radio displays signal strength, use this as a guide to ensure the best position.
Our DAB installation guide provides further information.
External aerials
It is important to check the cables and the aerial for damage and that they are operating correctly. Make sure any cables between your radio equipment and aerial are connected securely. For further information see our DAB installation guide.
Damaged Cables
Water can get into external cables and can cause reception problems. To rule this out see our guide on water damage to cables.
Car Radios
Radio reception can drop out when on the move due to changes in topography. See our car radio guide for more information.
Weather
Radio signals can be affected by fine weather including high pressure. The only solution is to wait for the weather to change, you should not re-tune during this time. Our information on how clear skies and fine weather can affect your radio reception may be useful, please see our weather guide.
Lost reception of one or more station within a multiplex
If all other stations are working ok and you have just lost one station. The problem could be due to a number of reasons, the station may have stopped broadcasting or have moved multiplexes rather than a radio fault. All of the stations in one multiplex should be behaving the same way.
Interference
If you are still having problems, it is possible an unwanted signal is the cause. For information on the .
Qualified Installer
The 鶹Լ cannot recommend individual installers. The is a recognised trade body which will be able to put you in touch with one of their members in your area.
DAB radio in the car
To listen to DAB in your car you will need to ensure your aerial is able to receive a DAB signal. You may need to contact your car manufacturer to check. However, helically wound FM aerials are able to receive DAB.
The best place to put a DAB aerial is on the roof of the car and as far from the engine as possible, to avoid any interference.
If your car radio is showing no signal or no service for a station you usually receive, this could be down to one of the following things:
DAB Transmitter Fault
If you know your location, you can use our transmitter checker to see whether there is a problem. If not, then check the radio and the aerial to confirm they are working correctly.
Interference
Poor DAB reception can also be caused by equipment used in the vehicle. For example, phone chargers or dash cams sometimes cause interference and affect your radio signal. Try unplugging the items to see if one of them is causing any interference.
Retuning & DAB Pre-set Stations
If you have bought a new car, the DAB radio may be tuned to DAB stations in a different location. Delete the presets and re-tune to the services in your area.
Topography
When travelling in the car, your signal can be affected by natural features of the land, for example, hills, valleys, rivers, etc. The signal should return once you move away from these features.
Part time/secondary radio services on DAB
Where can I find them?
When Radio 5 Sports Extra is on air, you should find it right next to 5 Live on the list of stations on your digital radio.
When do they broadcast?
Radio 5 Sports Extra has a dynamic schedule. To see what is available when, the 鶹Լ keeps a schedule on the sport website.
A marketing audio loop plays before and after the scheduled programmes.
How to find these services
It is best to re-tune your radio when they are broadcasting, so it will store the station in its memory.
Who is responsible for my Shared/Communal Aerial?
It is worth first checking to see whether the problem is with your own equipment, or the local transmitter. If neighbours are having the same problem it may be that the aerial itself is at fault, or there may be an interfering signal. In either case, you will need to ask your landlord or management committee to solve the problem.
Checking for problems
Check cables and leads within your property to ensure the problem is not a simple installation fault. Please see our Freeview Installation guide for further details.
To see whether there are any faults with the local transmitters use our Transmitter Checker tool. This will help you to see if there are, or have been recently, transmitter faults in your local area.
Electrical interference
There are differences between a reception problem and one caused by electrical interference. See our help guides which explain the differences. Our sister site, the also has useful information on how to distinguish the difference.
If it is potentially interference, your landlord or management committee can contact the regulator, Ofcom, for help with solving the problem, Since it is a communal aerial, you will not be able to contact Ofcom directly.
Freeview FAQs
Why am I receiving the wrong regional news?
Your television can sometimes receive signals from more than one transmitter, which may be transmitting different regional news. This is more likely to occur following a retune of your television. To ensure you are receiving the correct regional news programmes from the transmitter your aerial is pointing towards, you will need to do a manual retune. Please see our help guide on a manual retune.
If you are using satellite to watch TV, please see our FAQ here
If you're using cable to watch TV and are getting the wrong regional news, it is likely a technical issue and you'll need to speak to your cable provider.
For help setting the correct regional news on iPlayer, see our FAQ here
What should I do if my TV reception gets worse at night?
If you suffer from reception problems in the evening, this suggests that the signal getting to your television is not quite strong enough. Changes in the weather, temperature or atmospheric pressure can cause an already poor signal to break up or be lost.
To fix this, you will need to look at ways of improving the signal strength and quality. Once your receiving setup has been optimised (so you have a strong signal), if the signal does drop slightly in strength, your television receiver will still have enough signal to prevent the picture and sound from breaking up. We recommend you read the Good Installation Guide for suggestions on what to check.
It is also worth checking whether your television is tuned to the transmitter that supplies the best signal for your location. Use our Transmitter Checker Tool to see if you are in an area where more than one transmitter can be received. Then use our guidance on performing a manual retune, which allows you to tune to the best transmitter for your location.
Get help from an Aerial Installer
If you continue to have problems, consider the use of an Aerial installer. We cannot recommend individual Installers. However, the is a recognised trade body that will be able to put you in touch with one of its members in your area.
If you are a tenant or use a communal aerial system, contact your landlord/managing agent.
Why are subtitles sometimes delayed or out of sync?
For programmes which are pre-recorded, we create the subtitles in advance. A technician uses the audio and picture to sync them with what’s happening on screen. For a programme broadcast live, (like the News), subtitles will be generated as it is broadcast, which is a complex and problematic process. This means you’ll often notice a delay when watching live programmes.
How do I turn off the voice commentary (Audio Description) happening over my picture?
This is an accessibility feature called Audio Description. How you turn off Audio Description defers slightly depending on the platform you are using. Select the platform you use for instructions:
鶹Լ iPlayer
For instruction on how to turn off Audio Description on 鶹Լ iPlayer, visit our FAQ - Can I remove audio description on 鶹Լ iPlayer?
If you would like to learn more, check our Audio Description help guide
Freeview Help Guides
What is a good Freeview installation?
Aerials
There are all kinds of aerials available on the market and some which are specific to certain frequencies. A wideband aerial is a popular choice, although there are other aerials available. A qualified aerial installer with local knowledge will be able to advise further.
Height
Your aerial should be as high as possible pointing towards the transmitter with the best signal. Use the our Transmitter Checker tool to determine the best transmitter for your location. Ensure there is nothing in front of the aerial that could block the signal, such as trees. All TV reception predictions assume an outside aerial at a height of 10m from the ground.
Loft and indoor aerials
If you live close to a transmitter or can get a strong TV signal, then it could be possible to use an aerial in your loft or an indoor portable aerial. However, in both cases the signal will be weakened as it has to pass through various obstructions such as walls, roof tiles, foil backed insulation etc. Even if you are predicted to have good reception, you may have problems receiving services using indoor or loft aerials.
Cable and connectors
A television signal will always lose some of its strength as it passes along the cable and through the connectors. Therefore it is important to minimise the loss by using good quality cable and connectors.
Amplifier
These are not recommended unless absolutely required as they can introduce unexpected reception problems. See our help guide on the different types of amplifiers available.
Polarisation
Depending on the transmitter you are using, your aerial elements will need to be mounted flat (horizontal) or on its side (vertical). A qualified aerial installer with local knowledge will be able to advise further.
Qualified Installer
We cannot recommend individual installers. However the CAI () is a recognised trade body which will be able to put you in touch with one of their members in your area.
Troubleshooting your Freeview Television reception
Effects of poor Freeview reception are:
- loss of channels
- picture break up
- sound glitches/break up
Step 1 – Check if there is a fault with your local transmitter
First, use our Transmitter Checker tool. If there is a fault, it will be highlighted. If there is more than one transmitter listed, check all of them.If there is no problem with the transmitter, visit our Works & Warnings page. We advise of known issues, major transmitter work and whether high pressure or extreme weather could be causing problems.
If there is an issue with your local transmitter or you’ve found the answer on a Works & Warnings page, the problem should resolve itself without you doing anything. Consider using 鶹Լ iPlayer or 鶹Լ Sounds while you wait for the issue/work to be resolved.
Step 2 – Check the cabling
Start by checking the cables that are connected to the television or set-top box and the wall socket. They should be securely connected. If possible, try with another cable, in case the cable or connector is faulty.
Step 3 – Check your television is tuned to the transmitter with the best signalYou should get the strongest signal from the transmitter your aerial is pointing towards. Some Freeview reception problems are due to the receiver not using the best signal. This can be an issue when signals from more than one transmitter can be received. A manual retune will allow you to choose which transmitter signal to tune to. The Transmitter Checker can help figure out which transmitter your aerial is pointing towards.
Check our manual retune guide for instructions.
Step 4 – Check the aerial systemNext, you might want to consider getting your aerial installation checked. We cannot recommend individual Installers. However the is a recognised trade body and can put you in touch with one of their members in your area. If you are a tenant or are using a communal aerial, you should contact your landlord/managing agent.
Also, please read our guides on:
Other ConsiderationsObstructions between the aerial and transmitter can cause problems. Trees are the most common obstructions. They can affect the signal. This can be greater at different times of the year (when there are more leaves), when wet or in high winds.
Other examples of obstructions are newly built property nearby, or construction equipment, like a crane. If obstructions are too problematic to overcome and/or permanent, you might want to investigate if you can reposition your aerial and retune to a different transmitter. Another solution would be using another way of receiving services, like for example.
If you suspect trees could be a problem, read our guide What is the effect of trees on reception?
InterferenceIf after working though the steps above you are still having problems, it’s possible that interference (an unwanted signal interfering with your reception) could be the cause. Please see our other help site, the for further information.
How to check your cables for water damage
- If possible, check the external cable for any signs of damage, such as cracking and tears. Damaged cables can cause reception problems and can allow water into your installation.
- Find the cable that goes from your aerial or satellite dish into your television, radio or set top box and unplug it. This may be from a socket on the wall or a direct cable through the wall.
- If you are using a satellite dish to receive your television, you will also need to check the LNB and cap for any signs of water damage. You may need to instruct a qualified installer to assist you with this.
- If it is a direct cable, check for any obvious signs of water or a green build-up on the connector. If it is from a wall socket check both the connector on the cable and on the wall socket for any signs of water or green build-up. A green build-up is a sign that water has at some point got into your installation.
- If you find water damage then it is likely that the cable will need replacing by a qualified aerial installer.
We cannot recommend individual installers. However the CAI ( is a recognised trade body which will be able to put you in touch with one of their members in your area.
How to better my signal using an amplifier or attenuator
When to use an amplifier
A signal amplifier should only be used as a last resort when the television signal is weak. Even the best amplifier will still add some noise to the television signal it is amplifying/boosting that could result in picture break up. A good amplifier should have a filter built in that only allows the signal you want to be boosted and not any unwanted signals. Otherwise, all the unwanted signals will also be boosted, which can cause pictures to break up.
Problems using amplifiers
Amplifiers themselves are a common source of reception problems. For example, if water were to get into a masthead type, they can start to boost the result of the fault. This could be unwanted signals and result in picture loss on your own television and, maybe, those living nearby. To check, remove the power from the amplifier and see whether the problem goes away.
There are three types of amplifier – masthead, set-back and distribution. All these need a power supply to work.
Masthead
These fit directly under an outside aerial and usually the best type of amplifier to fix weak signals.
Set-back
These fit between the aerial socket in the wall and your television.
Distribution
These split the TV signal from a single aerial and allow the signal to be sent to several different televisions in the building.
Combined amplifiers
Some amplifiers are a mix of the above. For example, some masthead amplifiers are also distribution amplifiers. Some can also combine television and FM radio signals.
Attenuators
When to use an Attenuator
If you are experiencing pixellation or picture break up, it may be that your signal is too strong as this often presents itself similarly to a weak signal. This is likely to happen if you live close to a transmitter.
Attenuators can be used to decrease the incoming signal if it is too strong without distorting it. It is effectively the opposite of an amplifier, though the two work by different methods. While an amplifier provides gain, boosts the signal, an attenuator provides loss, reduces the signal. Attenuators are always a compromise and should only be used if absolutely necessary.
They come in a variety of powers; in most cases a small reduction is all that is needed. It may take a little trial and error to find the most suitable one for your installation, and it is worth taking the advice of a local aerial contractor to select the correct one for the installation.
Who is responsible for my Shared/Communal Aerial?
It is worth first checking to see whether the problem is with your own equipment, or the local transmitter. If neighbours are having the same problem it may be that the aerial itself is at fault, or there may be an interfering signal. In either case, you will need to ask your landlord or management committee to solve the problem.
Checking for problems
Check cables and leads within your property to ensure the problem is not a simple installation fault. Please see our Freeview Installation guide for further details.
To see whether there are any faults with the local transmitters use our Transmitter Checker tool. This will help you to see if there are, or have been recently, transmitter faults in your local area.
Electrical interference
There are differences between a reception problem and one caused by electrical interference. See our help guides which explain the differences. Our sister site, the also has useful information on how to distinguish the difference.
If it is potentially interference, your landlord or management committee can contact the regulator, Ofcom, for help with solving the problem, Since it is a communal aerial, you will not be able to contact Ofcom directly.
Latest Freeview works and warnings
Latest Radio works and warnings
Radio FAQs
Why can I hear a foreign radio station?
This normally happens in the summer months, due to high pressure weather conditions in the atmosphere, allowing radio signals to travel further. The cause is an atmospheric effect known as Sporadic-E and can last from a few seconds up to an hour or more.
For more information on how weather can affect your Radio services, please see our guide
Why is medium wave reception worse at night?
At night medium wave radio signals can travel much further than during the day. This means your radio is able to receive more radio channels either using the same frequency as the service you are listening to or adjacent to that frequency. The result is a higher level of interference and a deterioration in both the sound and coverage.
Radio Help Guides
Troubleshooting FM radio
Basic Installation
It is important to check your installation is working properly and that your radio is in the best possible position. We have a basic installation guide to help you with this.
Works and warnings
Check whether there are any known works or warnings that may be causing the problem.
Transmitter faults and frequencies
Use our Transmitter Checker to check the transmitter is not undergoing any work and to see which FM radio services you can receive from your location.
Hi-Fi radios
If you are using a Hi-Fi tuner and stereo reception is hissy, but mono is fine, your aerial may not be powerful enough. You may need to consider a loft or external aerial to solve your reception problem.
Weather
FM radio signals can be affected by fine weather including high pressure and the only solution is to wait for the weather to change, you should not re-tune during this time. Our information on how clear skies and fine weather can affect your radio reception may be useful, please see our Weather Guide.
Pirate Radio
In some urban areas Pirate Radio can be a problem. The regulator, Ofcom, deals with Pirate Radio and you can report it using the
Distorted S and Z sounds (sibilance)
This can happen when your radio receives more than one signal. The second signal is picked up by the radio moments after the first. For example you receive one signal directly from the transmitter and another is being reflected off a nearby hill. Try moving the radio or tuning to a different frequency.
Twittering and whistling
This often sounds like birds tweeting and happens if there is another frequency being transmitted near the one you are listening to. This can commonly be caused by high pressure when, during fine weather, radio signals can travel much further than normal. These signals can be both UK and foreign stations. There is nothing that can be done and the problem will go away when the weather changes.
Hissing and fading
This normally means that the signal you are receiving is not strong enough. See our guide on Hissing and Fading.
Buzzing, clicking and pops
This may mean an electrical item in your home or nearby, is interfering with the reception of your FM radio and is causing the buzzing, clicking or pops you can hear. See our guide on Buzzing and Clicking. If you are still having problems see our sister site for further information.
Distortion - fuzzy, gritty, scratchy sound
This is commonly caused by the FM signals being bounced off objects or hillsides and reaching your radio by different paths. Its technical name is multipath distortion. It is often worst in hilly or heavily built-up areas. Indoor portables are especially susceptible.
Distorted sound can also occur if your radio is off-tune. This can increasingly happen if your batteries are beginning to fail. Ensure your radio is correctly tuned-in, and check that your batteries are in good condition, or use mains power.
Humming
If you are hearing a hum it is often linked to an issue with your mains adapter. You may need to check that all parts of your receiving system are fully earthed.
What to do
If your radio is a portable, try moving the aerial to different angles. You could also try a different position in the room. Window sills and high shelves are good places for radios; avoid putting them close to radiators or electronic equipment such as computers, mobile/cordless phones or TV sets.
The telescopic aerial fitted to stereo portables is a compromise and the radio will often only give really good results if connected to an external aerial. If that’s not possible, switch to mono as it will usually sound better. Some sets do this automatically.
Make sure you are tuned to the best frequency for your area, as you can often pick up more than one signal. Use our Transmitter Checker to find the best frequencies for your location.
Qualified Installer
The 鶹Լ cannot recommend individual installers. The CAI () is a recognised trade body which can put you in touch with one of its members in your area.
Troubleshooting MW/LW Radio
Basic Installation
It is important to check your installation is working properly and that your radio is in the best possible location. We have a basic installation guide you can read.
Works and warnings
Check whether there are any known works or warnings that might be causing the problem.
Transmitter faults
By using our Transmitter Checker, you can check what MW/LW radio services are available at your location. It will also show you any transmitter faults.
Weather
AM reception can vary a great deal from day to night because of differences in the atmosphere. You may get good, clear reception during the day, but after sunset the signal may fade or become distorted. This is why you can often hear radio stations from outside the UK at night. Our information on how clear skies and fine weather can affect your radio reception may be useful, please see our Weather Guide.
Buzzing, clicking and pops
This may mean an electrical item in your home, or nearby, is interfering with your MW/LW radio. This is causing the buzzing, clicking or pops sounds you can hear. See our guide on Buzzing and Clicking. If you are still having problems see our sister site for further information.
Radio reception problems due to high pressure
Effect of Weather on Reception.
Weather-related problems tend to happen mainly in the summer, when high pressure can cause a radio signal to travel further than it would normally. This is known as tropospheric ducting. For more information see our guide on tropospheric ducting.
If this distant radio signal is on the same frequency as the one you are listening to it can cause a reception problem. This is because your radio will struggle decoding two radio stations on the same frequency. This is known as co-channel interference
The effect can last from a few hours to a few days and can cause intermittent effects on the service during that time.
What to do:
There is nothing that can be done but to wait until the weather changes. We have no control over it.
If your problem is due to the weather, it should go away once the weather changes.
Works and warnings
Check our works and warning page to see if there any current weather problems.
What type of radio aerial do I need?
FM Radio
The most common FM radio aerial on a portable radio is a telescopic one. To get the best reception extend the aerial fully and move the aerial and radio around until you get the best reception. If using a hi-fi with a wire aerial, again extend as much as possible to get the best signal.
External aerials are also available for FM radio and will significantly improve reception. The aerial and cables need to be well maintained and you will need a radio that has an option to connect an external aerial.
AM Radio
A radio which can tune to medium and long wave services usually has an aerial built in, which you cannot see. As the aerial is directional, by simply turning the radio you will be able to get the best reception. AM does not use the telescopic aerial.
Some hi-fi’s have external AM aerials that tend to look like many wires wound around a plastic loop. This needs to be rotated to find the best signal.
DAB radio
You need to have a suitable DAB aerial to receive DAB services. Portable DAB radios will usually have a telescopic one, but if you are retro-fitting a DAB radio into a car, you may need to add a DAB aerial.
External aerials are also available for DAB and will significantly improve reception. The aerial and cables need to be well maintained and you need a radio with the option to connect an external aerial. Unlike the other services, all the predictions of DAB coverage are for indoor coverage.
FM Radio in the car
Fading and Hissing
If you normally can receive a service, but you are now finding it is fading in and out, or you can hear hissing, this could be down to one of three things. The first is a fault with the local FM transmitter. Secondly, if you know your location, you can use our transmitter checker to see whether there is a problem. Thirdly, if not, then you will need to check the radio and aerial to confirm they are both working properly.
Interference
Poor FM reception can also be caused by equipment used in the vehicle. For example, phone chargers or dash cams sometimes cause interference and affect your radio signal. Try unplugging the items to see if one of them is causing any interference.
Reception in Tunnels
Depending on the specific tunnel and station, Radio reception can cut out or be lost when driving through tunnels. If the tunnel is deep, the radio waves will not reach into the centre, so your radio cuts out. Some tunnels are fitted with signal distribution systems both for FM and DAB so the signal will not be lost while in the tunnel. Or it could be “To help maintain the radio signals within the tunnel”
Tuning
Most FM car radios have a Radio Data System (RDS) built in. We use the RDS to ‘tell’ your radio if there is a better or stronger frequency for the radio service you are listening to, as you travel around. However, if you are using a frequency, you have preset and there is no radio service on that frequency in your location, then the RDS may not work. At that point you will need to tune your radio until you find a signal.
Aerials
If you are having continuous reception problems, check your car aerial for damage. If you have an extendable aerial, make sure it is fully extended to give the best possible reception.
Local Radio Travel News
The RDS system is set up to detect local radio travel news. The way to turn traffic announcements on and off on varies between radios. Check your car manual for yours.
AM radio in the car
Interference from car electrical systems
Interference to MW or LW reception in a car can be caused by many electrical systems within your car. From the ignition system to windscreen wipers or indicators. It usually sounds like whining or crackling sound, depending on the cause. Turning each element on and off to see if it goes away is one method to determine the cause but you may need to speak to an auto specialist
Interference from other electrical equipment
Other causes of interference to MW or LW radio in the car can include mobile phone chargers and dashcams. Check that connections are secure and cables are not damaged and see if the interference goes away of you move the equipment to other areas in the car.
On the move
MW/LW radio can also be affected by structures such as bridges and tunnels.
In simplistic terms, the size of the MW/LW wavelength is bigger than the radius of the entrance and struggles to reach into the tunnel or under the bridge. FM wavelengths are smaller so can usually reach in further by bouncing along the tunnel walls before they lose too much power
There’s nothing that can be done to improve this until you drive out from the tunnel or away from the bridge.
Radio Reception Help Guides
Buzzing and clicking on your Radio
Thermostat
The buzzing and clicking lasts from a few seconds to a minute at a time. Switch off heating systems and see whether the problem goes away. If the problem persists when you turn the heating system back on, the problem could be with the thermostat, which may need to be repaired or replaced.
Light switches
To find out if a particular switch is causing the problem, try turning the lights off one at a time.
LED lights
Many people are now using low power LED lights instead of the more traditional varieties. However, if the original light used a transformer rather than directly running off the mains, it is possible the transformer is causing the interference. This is because the transformer would have been designed to operate at the higher power and not the lower power the LED lights use. This has the potential to cause electrical interference.
Street lamps
Street lamps can sometimes cause buzzing and crackling sounds on your FM radio. Keeping a note of when each lamp comes on and goes off will help to identify whether this is the cause of your interference. If it is, contact your local council.
Passing traffic
A faulty or uncompressed engine can cause a distinct buzzing 'whine' which varies with engine speed - motorcycles tend to be the worst. Try to move your radio away from the street or use an external aerial.
Electric motor
An electric motor is used in many appliances such as electric lawnmowers, washing machines, drills and hairdryers etc. A faulty motor can cause electrical interference. Check any appliance with an electric motor by moving your radio away from it to see whether the sound improves. If you have several appliances with electric motors you may need to turn them all off and try the above one at a time.
With all of these potential causes, it is worth keeping a log for at least two weeks to determine whether there are any patterns or trends to the interference.
Hissing and Fading on your FM radio
This can be due to:
Reduced transmitter power
Use our Transmitter Tool to see whether your local transmitter is currently affected by maintenance work.
Stereo Signal
Try moving the radio to another position, such as near a window, higher up, or another room. If you get hiss when listening to a stereo signal try switching to mono. Stereo reception needs a stronger signal than mono.
Aerial
If you have a portable radio you will be able to pick up more of the receivable signal if your telescopic aerial is fully extended. For hi-fi systems check your aerial isn’t broken or become loose. If you have an external or loft aerial check they are functioning correctly.
Tuning to the wrong transmitter
Use our Transmitter Tool to check you are tuned to the best frequency for your area, as you can often pick up more than one signal.
Weather
Very occasionally, the weather, usually high pressure, can result in a weakened signal. There is nothing anyone can do about this and the only answer is to wait for the weather to change. For more information see our guide on how weather can affect radio reception.
Troubleshooting FM radio
Basic Installation
It is important to check your installation is working properly and that your radio is in the best possible position. We have a basic installation guide to help you with this.
Works and warnings
Check whether there are any known works or warnings that may be causing the problem.
Transmitter faults and frequencies
Use our Transmitter Checker to check the transmitter is not undergoing any work and to see which FM radio services you can receive from your location.
Hi-Fi radios
If you are using a Hi-Fi tuner and stereo reception is hissy, but mono is fine, your aerial may not be powerful enough. You may need to consider a loft or external aerial to solve your reception problem.
Weather
FM radio signals can be affected by fine weather including high pressure and the only solution is to wait for the weather to change, you should not re-tune during this time. Our information on how clear skies and fine weather can affect your radio reception may be useful, please see our Weather Guide.
Pirate Radio
In some urban areas Pirate Radio can be a problem. The regulator, Ofcom, deals with Pirate Radio and you can report it using the
Distorted S and Z sounds (sibilance)
This can happen when your radio receives more than one signal. The second signal is picked up by the radio moments after the first. For example you receive one signal directly from the transmitter and another is being reflected off a nearby hill. Try moving the radio or tuning to a different frequency.
Twittering and whistling
This often sounds like birds tweeting and happens if there is another frequency being transmitted near the one you are listening to. This can commonly be caused by high pressure when, during fine weather, radio signals can travel much further than normal. These signals can be both UK and foreign stations. There is nothing that can be done and the problem will go away when the weather changes.
Hissing and fading
This normally means that the signal you are receiving is not strong enough. See our guide on Hissing and Fading.
Buzzing, clicking and pops
This may mean an electrical item in your home or nearby, is interfering with the reception of your FM radio and is causing the buzzing, clicking or pops you can hear. See our guide on Buzzing and Clicking. If you are still having problems see our sister site for further information.
Distortion - fuzzy, gritty, scratchy sound
This is commonly caused by the FM signals being bounced off objects or hillsides and reaching your radio by different paths. Its technical name is multipath distortion. It is often worst in hilly or heavily built-up areas. Indoor portables are especially susceptible.
Distorted sound can also occur if your radio is off-tune. This can increasingly happen if your batteries are beginning to fail. Ensure your radio is correctly tuned-in, and check that your batteries are in good condition, or use mains power.
Humming
If you are hearing a hum it is often linked to an issue with your mains adapter. You may need to check that all parts of your receiving system are fully earthed.
What to do
If your radio is a portable, try moving the aerial to different angles. You could also try a different position in the room. Window sills and high shelves are good places for radios; avoid putting them close to radiators or electronic equipment such as computers, mobile/cordless phones or TV sets.
The telescopic aerial fitted to stereo portables is a compromise and the radio will often only give really good results if connected to an external aerial. If that’s not possible, switch to mono as it will usually sound better. Some sets do this automatically.
Make sure you are tuned to the best frequency for your area, as you can often pick up more than one signal. Use our Transmitter Checker to find the best frequencies for your location.
Qualified Installer
The 鶹Լ cannot recommend individual installers. The CAI () is a recognised trade body which can put you in touch with one of its members in your area.