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aerial' for analogue reception, but as they are generally unsuitable for Freeview reception, they have now generally been replaced by the Yagi type.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?
Saturday, 29 October 2011
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tom9:52 AM
Ive just moved into a new place and was pleased it had tv aerial ports next to plug sockets in the bedrooms and kitchen. Trouble is - they don't seem to work.the one in the living room works fine - full freeview channels but is now redundant as sky fitted. I've been up in the loft but cant see where the wire comes in from the roof...not sure what to do now so any advice appreciated...
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tom: It is possible that the other sockets are connected to an "in" point near where you have found the working aerial point.
It is not likely that the cable will come in via the roof, but be routed on the outside of the building.
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Steve P7:30 PM
tom - did you remove the fascia plates and confirm they are connected to SOMETHING?
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Monday, 31 October 2011
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Tim1:05 PM
I have a digital TV working perfectly on an existing analogue ariel which looks like a Yagi type. I have been told that once analogue is closed down in April 2012 i will lose some of my digital channels and that the problem will get worse. Is that right or is someone just trying to sell me an unnecessary new ariel?
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Tim: Yes they are.
To be sure, please provide a full postcode.
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Wednesday, 2 November 2011
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suzanne1:49 PM
Bangor
my tv just says no signal although im in a freeview area, what would you recommend i do
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suzanne's: mapS's Freeview map terrainS's terrain plot wavesS's frequency data S's Freeview Detailed Coverage
Thursday, 3 November 2011
suzanne: You need to make sure your aerial is pointing at the Divis transmitter, as only this carries Freeview services.
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Sunday, 6 November 2011
I have a very old wideband, high gain TV aerial I bought many years ago to try my hand at TV DX'ing. On a good day I could just about make TV South West. Happy days!
I am starting to think it is past its best as I don't get very many Freeview channels from the Crystal Palace, Sudbury or Bluebell Hill transmitters. Access to the aerial is easy via a flat roof so I have been able to turn it round to point in any direction.
Two questions.
1. Should I be getting better signals than I am from this location SS7 3PW about 100m asl?
2. Will a standard (non-wideband, non-high gain) aerial still work with Freeview from Crystal Palace after DSO?
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Dave's: mapD's Freeview map terrainD's terrain plot wavesD's frequency data D's Freeview Detailed Coverage
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Steve P3:54 PM
... UK digital TV reception predictor
Dave - you probably know the above site to tell you what to look for. NB I have set 100m above GROUND where you are, not sea level.
Dunno about the specifics but mostly if it works now it still will after DSO - except where there are odd frequency changes and low strengths.
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jb384:10 PM
Dave: If I could add to Steve P's link, if you copy and paste in this link also it will give you an idea of the situation, because as you will see you are only forecast to obtain reliable reception from Sudbury (@ 31mls/14 degrees) or Rouncefall (@ 5mls/59 degrees) both these stations operating on the same frequency.(SFN)
As far as Crystal Palace is concerned only BBC1 is shown as good, the remainder being variable.
I am not sure what you mean by "standard" (re: No2) when referring to the aerial, but after DSO although a wideband aerial will work perfectly OK, if though you want that little bit extra gain then go for a group A aerial, this covering (and more) the DSO channel span of 22-30.
Crystal Palace going from its present level of 20Kw (10Kw HD) up to a massive 200Kw.
Postcode Checker - Trade View
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