Top tips All about aerials

Top tips
All about aerials
To watch Freeview you need a suitable aerial, correctly aligned and in good condition. Aerials
are designed to work either with a specific group of broadcast frequencies (grouped), or across
all airwaves that can be used for TV transmission (wideband). A coloured stopper or 'bung' on
the end of an aerial identifies which group of frequencies it is designed to work with.

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A black stopper indicates a wideband aerial. Most aerials sold today are wideband as these are
best suited to dealing with any changes to TV signals. Some Freeview signals are set to change
around 2020 to make space for more mobile broadband services (see box below).

If you can't see a coloured bung on your aerial - this can be difficult from the street - you may be
able to tell if it's grouped or wideband by the size and distance of the elements or fins along the
body. On a grouped aerial these will generally be a consistent size and evenly spaced. A
wideband aerial will have different lengths and spacing.

Why are some aerials flat and others on their side?
Aerials need to be either horizontally or vertically polarised, depending on the transmitter you
are receiving your signal from. In most cases, viewers receiving their TV signals from a main
transmitter will need a horizontally polarised aerial. Homes served by smaller relays generally
require vertical polarisation.

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What type of aerial do I need?
A good local aerial installer can advise on the type of aerial you need for your area. We
recommend consulting an installer who is a member of a recognised trade body, such as the
Confederation of Aerial Industries (CAI) or the RDI. Information about this is also available on
the detailed view of our coverage checker and from the Freeview advice line on 03456 505050.
The example below shows that a horizontally polarised group A aerial (A H) is suggested to
receive services from Crystal Palace.

Digital UK recommends using a rooftop aerial for best results. Our predictive coverage checker
is modelled on homes using a rooftop aerial at 10 metres above ground level. Loft aerials
(rooftop aerials installed inside a home) or portable indoor aerials may work in areas where there
is good reception but can be subject to electrical interference from other domestic appliances.

Communal aerials
If you live in a block of flats or a shared household you may have a communal TV system,
designed to provide a signal to several homes from a single aerial. These may also be used in
areas where planning constraints restrict the use and number of rooftop aerials and satellite
dishes. Some communal systems need to be retuned following changes in broadcast frequencies
or the launch of new channels. If you have questions about a communal aerial system, contact
your landlord or managing agent.

When might I need a new aerial?
Aerials generally last for a long time but rooftop installations can be affected by weather over
time. If your current picture quality is poor and you are happy that your TV equipment is
correctly tuned and in good working order, you might have a damaged aerial or cable that needs
attention from a professional installer. Loft aerials and portable set-top aerials can work in areas
where there is good reception but can be subject to electrical interference from other domestic
appliances. Where this is the case, you may need to consider moving to a rooftop aerial if you
cannot identify and resolve the issue.

On rare occasions technical changes at your local TV transmitter may mean you need a different
type of aerial to receive all available channels.

How do I buy or replace an aerial?
When buying a new rooftop aerial or replacing an existing one we recommend contacting an
aerial installer who is a member of a recognised trade body, such as the Confederation of Aerial
Industries (CAI) or the RDI. A local installer will understand the circumstances and geography
of your area and suggest the best option. Based on industry guidance, a typical aerial
replacement costs £150. However, there can be regional variation and complex installations can
cost significantly more. Additional aerial socket costs around £45.

Guidelines for choosing an aerial installer:

      Ask friends and family for recommendations
      Look for an accredited installer who is a member of recognised trade body
      Get at least three quotes. Installers who are members of trade bodies should have a menu
       of prices for typical jobs and be able to give you an accurate quote before they start work
      Be clear about the work to be done and agree all details in writing
      Only pay for work once it has been completed
      An installer should be able to show you their trade body (CAI or RDI) membership card
       before they enter your house or start work. Don't be afraid to ask

Changes to Freeview airwaves

The Government has taken the decision to reallocate some airwaves currently used by Freeview
for the future launch of new mobile broadband services. This is designed to meet a predicted
increase in the demand for mobile data. The process began in Scotland in summer 2017 and is
now underway across the UK, region by region. It is expected to be completed by 2020. More
information, including details of the free support available for viewers, is available at
www.freeview.co.uk/tvchanges

Most Freeview viewers will simply need to retune their TV equipment when this change takes
place in their area. However, Ofcom has stated that between 100,000 -160,000 homes currently
using a grouped rooftop aerial may need a replacement be sure they can continue to receive all
available channels in their area. Some viewers may also need to repoint their aerial or install a
small filter at the back of their TV to prevent interference once new mobile services launch.

Viewers in the process of replacing their aerial in areas where signals are transmitted in
Group C/D are recommended to consider a wideband model.

More information on wideband aerials is available from the Ofcom website. More detailed
information on these changes for industry can be found in our section on 700MHz clearance.

In the budget statement of March 2015 the Chancellor of the Exchequer announced that funding
would be set aside for these changes to airwaves.

General Troubleshooting
Occasionally you may experience an issue with your TV reception, such as a pixelated picture or
missing channels. Most problems are easily diagnosed and resolved. Digital UK recommends
that any maintenance on rooftop aerials is carried out by a qualified installer. Common causes
are listed below:

      Damaged aerial or cabling/loose connections

Loose or damaged connections can result in picture problems. You should check that all cabling
is secure and in good condition, including both your external aerial lead/plugs and any
interconnecting cables between devices (between your TV and a set-top box, for example). Bad
weather can also cause damage to your aerial over time, particularly where water penetrates and
corrodes the cabling. You can find out more about this here.

An aerial that's out of position and no longer pointing directly at the correct transmitter can also
be the cause of reception difficulties.

      Unnecessary amplifiers and splitters

Aerial amplifiers previously needed to receive analogue or low power Freeview signals before
switchover are a common cause of reception difficulty - these can actually overload equipment.
Similarly, aerial splitters may result in a weak signal. Removing these can often resolve an issue.

   Wrong transmitter/signal overlap

Depending on where you live, you may be able to receive signals from more than one TV
transmitter. This is quite normal in some areas but can cause problems where equipment
automatically tunes to a weaker signal, or one that provides the wrong regional news services for
your location. Manually retuning your TV or set-top box to the correct transmitter for your
address can help ensure the best reception.

In some cases, problems can arise where aerials aren't aligned to the best transmitter (for
example, your aerial may be pointed at a distant large main transmitter but receive a much better
signal from a smaller, local relay). Redirecting your aerial can improve reception.

      Atmospheric conditions

Certain weather conditions, including high pressure (which generally brings fine weather or
morning fog), may occasionally affect your Freeview reception. Interference caused by
atmospheric conditions is temporary and should clear once the weather changes.

      Engineering works

Changes and future improvements to terrestrial TV services sometimes require engineering work
on transmitters. While every effort is made to minimise the impact on viewers, this can cause
temporary disruption to reception. You can check to see if there is planned engineering at your
local transmitter here.

      In-home interference

Some home appliances can disrupt reception by causing power fluctuations at the mains where
your TV equipment is connected. Switching off other devices around the home can help identify
if these are the cause of a problem. Common culprits include fridges, washing machines and
tumble dryers, fluorescent lighting systems, lawnmowers, central heating systems and water
pumps. Fitting a mains filter to your TV equipment and keeping your aerial and video/audio
leads away from other electrical cables can help prevent interference.

Note: Mobile and cordless phone handsets, baby monitors and walkie talkies can also affect TV
reception when used in close proximity to your reception equipment, aerial or cabling.

      Local external interference

Traffic, roadworks and radios used by the police or taxi companies can affect TV reception.
Fitting a filter to your aerial and ensuring all cables are in good condition can help to prevent
this.

      Obstructions

Trees, tall buildings and other local topography (ie hills) between a transmitter and your home
can prevent clear reception by blocking or reflecting the signal. Where this occurs, a good local
aerial installer may be able to advise on possible solutions, such as redirecting your aerial to an
alternative transmitter.

      4G interference

New 4G mobile broadband services operating in the 800MHz band can cause interference to
Freeview signals in some areas. In many cases this can be resolved using a simple filter fitted
between your aerial cable and your TV. A company called at800 has been established by the
mobile phone operators to resolve these reception issues for viewers.

      My reception is fine but I'm missing channels

Channels on Freeview can change from time to time - some may be removed, others added and
channel numbers can change. Try retuning your TV equipment once in a while to make sure you
have the latest channel line-up for your area.