Back to Contents

6.3 DAB Digital Radio Reception

DAB Digital Radio does not suffer from the audio impairments described in Section 6.2 that occur on analogue radio.  Provided you have sufficient signal level to overcome interference, the audio quality will be at the same level as that transmitted wherever you are in the coverage area.

  • Can I get DAB at my postcode?
    You need a new digital set to receive signals, which is labelled "DAB" (for digital audio broadcasting). You can get more advice about sets and check coverage in your area using our Digital Radio website http://www.bbc.co.uk/digitalradio/
  • Why doesn’t my new DAB portable radio work?
    If the postcode coverage checker says you are “Very Likely” to get reception then most portables should be fine. If it says you “May Get” reception then we’ve found some portables don’t work well – or even at all. Some radios now on the market need more signal than others to work reliably. It’s therefore possible some models may be less effective than others.

If you can unscrew the fixed aerial and attach a cable from an external DAB aerial, this usually solves the problem. Check if the radio can take an external aerial before you buy – most can (please refer to the user manual or contact the manufacturer). Good installers can be contacted through the CAI.

It’s very rare for the problem to be caused by transmitter faults. Not only are they very reliable, but signals from more distant transmitters reinforce reception even if your local one happens to be off the air.  Ultimately, it’s very difficult to make the postcode checker accurate for all locations and receivers. Therefore it can only be a guide.

  • What is the difference between ‘stations you are very likely to receive’ and ‘stations you may receive’ on the DAB postcode checker?
    Experience has shown that if the postcode check says you are ‘likely to receive’ the stations listed, a portable should work around the home. If the check says you ‘may receive’ the stations you want, portables may need careful positioning and in some cases, an external aerial may be needed to give consistent results. Please remember that results are a prediction and not a guarantee. Reception may be more difficult if you have thick stone or reinforced concrete walls, use a radio with poor sensitivity, or live in an unusually shielded location.
  • Why can I no longer receive my BBC stations?
    The difference between good reception and failure for DAB Radio is like a cliff-edge. This means while you may appear to have perfect reception, your radio may be processing a very weak signal - near the point of failure. If you suddenly lose your services it is possible that there has been a further (even though slight) reduction in the signal and your radio can no longer decode the signals. A drop in signal strength may be influenced by many factors - weather, air pressure, tree growth to name but a few. It is however highly unlikely to be a transmitter issue as all our broadcasts are monitored. This effect may be particularly prevalent in variable coverage areas. Because local radio services often use different transmitting sites from national ones, their received strengths may be different where you live. You may therefore find them affected differently from BBC national stations.

    Firstly, you should check what the predicted DAB coverage is for your postcode, as this may help to understand the problem.

    For optimum signal strength, a proper outside DAB aerial can help, but there is no guarantee of success. Remember also that to do this your radio needs to have an aerial socket; not all portables do. The only sure way of knowing whether an aerial will achieve good reception is for a qualified installer to measure signals at your home. The Confederation of Aerial Industries (CAI) is a trade body representing installers who guarantee their work and operate to a Code of Practice. You can contact them via their website http://www.cai.org.uk/asp/home.asp which has details of local installers.
  • When will coverage improve?
    The BBC continues to build new transmitters and UK national coverage is currently around 85% of the population. In some remaining areas, only commercial stations can be received where BBC coverage has not yet reached.  The BBC is committed to further improvements in DAB coverage as detailed in the BBC's Building Public Value document.
  • I get bubbly sounds - why?
    Even in a good coverage area you may have a weak signal. If you use a portable radio, make sure the aerial is fully extended. Try placing it higher up and away from metal surfaces such as cookers and fridges. Sometimes, placing the radio on a window-sill can help and you may find reception better upstairs than downstairs. Unfortunately, some radios are less sensitive than others (some personal stereos with headphone-lead aerials, for example) and need more careful positioning to work reliably.

Good indoor reception depends on many factors - the signal strength; sensitivity of the radio and its aerial; where it’s used in the house and, very importantly, the materials from which the building is made. This may include thick stone or reinforced concrete walls, or perhaps an unusually shielded location.
If you use a DAB hi-fi unit and find the supplied aerial is not giving good results, you may need a proper DAB (Band III) aerial. They are best used outside, but can give acceptable results in lofts.  In most cases it’s best to have a DAB aerial professionally installed by an installer registered with the Confederation of Aerial Industries (CAI).

FM reception tends to get noisier the worse the signal gets, so that even with a very weak signal, some reception may still be possible in mono. DAB reception has a threshold effect where reception can still seem excellent until a point is reached at which a further tiny reduction in signal can cause severe break-up or complete silence. Some DAB radios have a signal strength or quality meter which can help you find the best position for your radio.
If you get no signals at all, check that your area is predicted to be covered by the postcode checker. If you're buying a radio, please ask your retailer to check coverage. This applies especially if it's for someone else, as reception may be different where they live.
  • Why do some stations work better than others?
    Coverage can vary when transmitters are in different locations. If you find reception of BBC national stations different to local BBC or commercial stations, it may be because coverage varies and the transmitters are in different locations. If you are having difficulty, try to improve your overall reception using the approaches already mentioned. In many cases, the postcode checker may indicate different coverage for different stations.
  • I can’t get my BBC local radio station on DAB
    Not all local BBC radio stations are available on DAB yet. BBC Local Radio services are carried on capacity made available by commercial platform operators. This is because our own digital multiplex is already used to full capacity for our BBC national services. As a result, in some areas where a commercial licence has not yet been awarded, BBC local radio is not yet available on DAB.

Commercial DAB licences are awarded by the regulator OFCOM. For more information about when one will be made available in your area please contact OFCOM on 0845 456 3000 or visit their website at http://www.ofcom.org.uk.
We are unable to advise on issues of DAB local radio reception and listeners should refer to the commercial broadcaster operating the multiplex.

  • Can DAB suffer from interference?
    Yes, domestic equipment can interfere with signals. Though DAB is more resistant to interference than FM, it can still be interrupted if the level of interference is high. If there are regular bursts of interruptions, domestic equipment may be the cause. To confirm this, try listening to FM when the problem is present. A distinct crackle indicates a burst of interference.

Most local interference is caused by central heating thermostats. To check, turn off the heating for a few minutes and see if the problem stops. A neighbour’s system may be causing the problem rather than your own, in which case check next-door to see if they have intermittent noise on FM, TV or even cordless telephones. Other sources of interference include fridge thermostats, faulty fluorescent lights and very occasionally even electricity street transformers and street lamps.

  • Can an outside aerial help if signals don’t fully cover my area?
    It depends on the signal strength where you live. Proper outside DAB aerials can help, but there is no guarantee of success. Nevertheless it’s worth being prepared to install an outside aerial if you are in an area of patchy coverage.  Remember also that your radio needs to have an aerial socket to connect an outside aerial; not all portables do. The only sure way of knowing whether an aerial will achieve good reception is for a qualified installer registered with the Confederation of Aerial Industries (CAI) to measure signals at your home.
  • I can't get a good reception in my car
    This could be due to having a windscreen aerial. Many cars use rear windscreen aerials. These can be highly directional and may work acceptably when facing one way, but poorly when facing the opposite way. This may cause poor reception; even body-mounted aerials can pick up less well from some directions. If you don’t have a windscreen aerial, you will also need individual advice.  For more help with mobile DAB radio aerials you need to contact your car radio dealer
  • Can a new local transmitter interfere with reception?
    Yes, this has happened in some areas. We are investigating the problem but have not yet found a solution but repositioning your aerial may help.

Continue 6.4 >>>

Back to Contents