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6. Recommendations

If you are having problems with TV or Radio reception, and the quality of reception has deteriorated over a period of time, the most likely causes are a deterioration in the quality of your receiving installation or newer obstructions between your house and the transmitting station (e.g. new buildings or growing trees).  Transmitting stations are regularly maintained and checked for performance so the station performance will remain as good as the day the station was first built. There can be temporary faults with transmitting stations that can cause reception problems but these would not be left unrepaired over a significant period of time.
The information in the following sections, extracted from the BBC’s Reception Advice website http://www.bbc.co.uk/reception, describes the most common problems people experience with reception of analogue TV, analogue radio, DAB digital radio and digital terrestrial TV (Freeview).  If your question is not answered in this quick guide, you can obtain more detailed information in one of our factsheets available at http://www.bbc.co.uk/reception/factsheets/index.shtml

6.1 Analogue TV Reception

Most areas of the UK have good analogue coverage of BBC One, BBC Two, ITV, Channel 4 or S4C. Channel 5 is also available to many people on analogue TV (although coverage of Channel 5 is incomplete on the south coast of Dorset).  There are a number of possibilities you can examine to improve your TV reception.

bt3Aerials and connections
For good reception you need the right kind of aerial, correctly sited with good quality cable and connections. Aerials and cables both deteriorate over time and this is often the cause of reception difficulties.

Aerial 1

Aerial 2

Fig. 27 – Examples of rooftop aerials

To get the best reception for television you need to make sure your aerial is in good condition and pointing correctly towards the best local transmitter.  We always suggest you should get a professional CAI (Confederation of Aerial Industries) registered aerial installer to check this for you.  The cables and connections which run from the aerial to the television are equally important and should be checked regularly. Older aerials, cables and connections often need checking or replacing, especially near the sea where corrosion can occur quickly.


uyWeak Signals
Are you getting a fuzzy picture, distorted sound, or no picture or sound? This indicates that your TV set is not receiving a strong enough signal. If this has only just started, first check if your local transmitter is off air or undergoing maintenance.
http://www.bbc.co.uk/reception/transmitters/today.shtml
If there is nothing reported for your transmitter today or if you have had the problem for some time, it could be caused by your aerial or TV set.

  • Check the TV set is tuned to the channel in question.
  • If it affects more than one channel, check your connections. Is the aerial lead securely plugged into the TV or video? Check the connections in between the TV and video.
  • Is your TV working properly? Try playing a video or DVD.
  • If you have an external aerial, check it isn’t broken. Wind can blow it out of alignment. Is it pointing the same way as other aerials nearby? Aerials and their connections should be checked and possibly renewed every 10 years.
  • Ask the neighbours. Are they having the same problem?
  • You may need a professional to check your system.

iyThe effects of weather on analogue TV, Freeview, Satellite and radio reception
In periods of high air-pressure (hot weather), viewers and listeners may notice some deterioration in the reception of some services. This is because the atmospheric conditions allow signals to reach areas other than they would in normal circumstances. In some cases this might mean a reduction of signal strength to viewers/listeners in low-lying areas. Mainly the result is an overlapping of signals which causes interference. On analogue television this may produce a ‘Venetian blind effect’ (Co-Channel Interference) or a generally poor picture.   This phenomenon may only affect one or two channels while the others appear to be being received normally.

On rare occasions, viewers using Digital Terrestrial Television (Freeview) may experience picture break-up or even a complete loss of reception from time-to-time, as a result of weather-related interference. However, digital reception is far less prone to interference problems than analogue television.
Analogue radio listeners may notice other stations interfering with normal broadcasts or hear ‘birdie’ noises (warbling, sizzling, frying-type sounds in the background). In exceptional instances, listeners may even hear foreign language stations coming through loud and clear. Unfortunately, as a broadcaster, there is nothing we can do to prevent this and things should improve when the weather changes. In periods of high air-pressure viewers/listeners are advised not to adjust their aerials or to call anyone out to look at them as the service will most probably return to normal when the weather cools.
Heavy rain can result in satellite users temporarily losing services. This is due to either the ‘up-link’ signals to the satellite being blocked or as more commonly the ‘down-link’ signals to the viewers’/listeners’ dish being blocked by the storm. Services should return once the storms have passed.

Terrestrial viewers (both analogue and digital) who notice a continued deterioration in reception after storms or heavy rain should check water hasn't got into the aerial or the cable running down from it. Checking with neighbours to ask if they have any reception difficulties is also a good idea as this helps identify if the problem is limited to your own equipment or is the result of other factors. 

        
noneGhosting
This means seeing a double image on the screen. TV signals bounce off solid objects like hills, tall buildings or cranes and reflect from shiny surfaces like the sea. When this happens it creates a second, delayed signal that you can see on the TV screen as a ghost-like repetition of the main picture. One way to try and exorcise the ghost from your picture is to move your aerial slightly from its current position. Assuming it is currently pointing directly at the transmitter, angling it away by just a couple of degrees may improve your picture. You will lose some signal level but may gain a better picture overall if you can avoid picking up that reflected signal. Ghosting can usually be reduced or solved by changing to a more directional aerial which focuses on the main signal and is better at ignoring other ones.

ghosting

Fig. 28 – Appearance of ‘ghosting’          

bgInterference
This is where the signal you want to receive is distorted by other signals or objects before it reaches your TV set. There are three main sorts of interference.

jesCo-Channel Interference
Smooth, evenly spaced horizontal bars (‘Venetian blind’) indicate Co-Channel Interference. This occurs when a second television signal, normally out of range of your aerial is received along with the channel you wish to watch. This happens when high air pressure (usually the bringer of fine weather) causes TV signals to travel further than normal. Unfortunately as a broadcaster there is nothing we can do to prevent this, however things should improve when the weather changes.

co channel inteference

Fig. 29 – Appearance of co-channel interference

jesElectrical Interference
Ragged, moving horizontal patterns indicate electrical interference. This is caused by equipment near your TV or aerial. Items such as computers, thermostats, domestic appliances or anything powered by electricity can cause it. To cure the problem you first need to identify the source of the interference. Don’t forget that this could be outside your home. Once you have found it either move the item or have it shielded to prevent the interference.

electrical

Fig. 30 – Appearance of electrical interference


jkguRadio Interference
Moving, wavy or herringbone patterns on the screen are caused by radio interference.
These usually come from radio communications used by:

noise

  • Emergency Services
  • Private Business Radio (PBR) as used by taxis
  • Amateur Radio
  • Citizens' Band radio
  • Mobile Phones
  • Pirate radio broadcasters

 

Fig. 31 – Appearance of radio interference

Responsibility for licensing users and preventing illegal broadcasting rests with Ofcom

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