Freeview reception - all about aerials
Updated 8th January 2014.
Your ability of receive all the Freeview transmissions depends on the suitability of aerial
- the design style,
- the "group", and
- its physical location.
Standard type - Yagi aerial
The standard type of TV aerial is known as the Yagi aerial. It is mounted on a pole, and consists of a rod with a reflector (shown green) at the back and many spiky elements (in grey) at the front. The connecting cable connects to the element nearest the reflector, known as the driver (shown in blue).
These Yagi aerials are directional and so pick up signals best from a transmitter that the rod points towards. The more elements the aerial has, the better it picks up a signal and becomes more directional.
A standard-type aerial is all that is required for digital TV reception in most places. These antennae have between 10 and 18 elements and a single reflector. These are recommended for new installations for good digital television reception, but will more often than not function perfectly in good reception areas.
Typically these aerials are designed to receive only some transmission frequencies - see "groups" below.
High Gain aerials
These aerials are designed for poor digital reception areas, and have two reflectors. For maximum signal strength, some digital high gain aerials have up to 100 elements. Since the switchover to digital-only transmissions back in October 2012, most UK households now have good quality digital TV signals.
A more expensive aerial is only required where the signal strength is low, but can often provide the whole Freeview reception where it might otherwise be impossible.
The CAI (that represents aerial installers) has four standards for digital TV aerials. The highest standard "1" is for homes on the fringes of coverage areas, intermediate standard "2" is suitable for use within the coverage area; minimum standard "3" is for good coverage conditions.
These aerials can be either wideband, or receive only selected frequencies - see "groups" below.
Grid
You may haved used a 'Grid aerial' for analogue reception, but as they are generally unsuitable for Freeview reception, they have now generally been replaced by the Yagi type. However in some places a Grid aerial installation may work for Freeview: otherwise replace with a standard Yagi aerial.
Indoor
Indoor aerials are generally not suitable for Freeview reception. In areas of good signal strength it is often possible to receive some transmissions. Even where an aerial works, people often find that may get interruptions to their viewing (or recording).Loft mounted
Loft mounted arrivals are not generally recommended for Freeview reception, as the roof tiles and plumbing will degrade the signal. Some compensation for this loss of signal can be made by using satellite-grade cable to connect the set top box to the aerial.Positioning
The best position for a TV aerial is mounted outdoors, as high from the ground as possible, pointing directly at the transmitter. The signal can be blocked by hills and tall buildings. It should be positioned away from any other aerials.Horizontal or vertical?
The transmitter will either use vertical mode which requires the elements of your aerial to be up-down, or horizontal mode which requires them to be level with the ground.Groups
Both analogue and digital television is transmitted the same group of transmission frequencies (known as channel 21 through to 60). A coloured marking on the aerial shows the group.To create the best possible analogue picture, TV transmissions from adjacent transmitters have been designated to several different groups of frequencies. By using an aerial that receives only the channels in the correct group, the analogue picture can be kept free from interference.
To receive Freeview transmissions from the same transmitter it has been sometimes necessary to use frequencies that are not part of the transmitter's normal group. When this has occurred, the aerial will need to be replaced with a "wideband" aerial (also known as group W) - one that covers every group.
As Ofcom is planning to move the TV frequencies again - perhaps as soon as 2018 - it may be wise to use a wideband aerial if you can to ensure you can keep viewing Freeview for many years to come.
Help with Television sets?
Tuesday, 2 August 2011
Graham: DAB - Digital Audio Broadcasting | ukfree.tv - independent free digital TV advice - not sure who actually owns it.
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Friday, 5 August 2011
M
Mark3:10 PM
Milton Keynes
Hi All total novice so please bear with me! I have a caravan at the post code of MK19 7JP I have small digital aerial. Its pointing in the same direction as all other aerials on the site about 86 degrees by my iphone! I can get most channels but the TV is saying the some are at 14% coverage and the channels stop, cut out and are not solid steady channels? I have checked all the cables and reconnected all the end tight but made no difference? Do I need a high gain aerial as some people on the blogs state?
Thanks to anyone who helps me!
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Mark's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
J
jb383:44 PM
Mark: You should be able to get good reception from Sandy (Anglia) on its three main Mux transmitters "if" your aerial is mounted on a normal pole in the same way as done in most caravan installations.
What you have said suggests that you are using an indoor (set top) type of aerial, and if you are that is not good enough at the distance you are from the transmitter, Sandy Heath being 26 miles away.
You don't really require a so called "high gain" type, as a standard log periodic aerial called a Log 40 is suffice, these being easy to mount as they do not have the usual large reflector on the rear.
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M
Mark4:35 PM
Hi jb thanks for your help, the aerial is on a small pole about a foot long outside on the top of the caravan? It does how ever have a small splitter that connects 2 rooms so not sure if that maybe the problem?
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J
jb385:10 PM
Mark: A splitter of a non-powered type will drag a signal down, for a test try coupling the TV directly to the aerial, if you find its OK by doing that then purchase a powered two outlet splitter, as that will provide exactly the same signal strength to the two TV points, even possibly with it being slightly boosted!
I would normally have suggested Argos as a possible source of the splitter, but they have really gone downhill with their selections, only offering a SLX two way version @ £19.99, you can get one much cheaper than that.
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Mazbar5:49 PM
Ormskirk
Mark is it a static caravan if it is the splitter is normaly under the caravan. A splitter is ok as long as the signal is ok going in. A local aerial rigger could fix everything for you, it cost more than argos but you have someone to come to you and fix everything you.
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Mazbar's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
Sunday, 7 August 2011
R
Richard Chapman2:17 AM
Since Easter 2011 i have been unable to receive digital signals for the BBC channels , ITV ,C4 and C5 during daytime and early to mid evenings . Before this i was receiving signals fine. However , i am receiving these channels fine at nightime which indicates that my equipment is working fine . Should i assume that something or someone is disrupting my signal ? How do i go about resolving this. My neighbours do not have this problem.
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S
Steve P10:20 AM
Richard - sounds like your aerial is wrong.
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Monday, 8 August 2011
Richard Chapman: Can you please have a look at Freeview intermittent interference | ukfree.tv - independent free digital TV advice ?
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Tuesday, 9 August 2011
S
steve1:11 PM
Alnwick
Hi,
my postcode is: NE66 2XL.
I have an indoor aerial (very old) and freeview box. I get nearly all channels but a few are missing/bad. Do i need a new aerial ? Where is my transmitter ?
Thanks for all your help
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steve's: mapS's Freeview map terrainS's terrain plot wavesS's frequency data S's Freeview Detailed Coverage
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