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aerial' for analogue reception, but as they are generally unsuitable for Freeview reception, they have now generally been replaced by the Yagi type.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?
Monday, 21 February 2011
Dave sharp: You should put the aerial on the roof where it can have a clear line-of-sight to the transmitter.
This is a much more reliable option than using boosters and amplifiers.
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Dave sharp7:37 PM
Anstruther
Thanks for advice briantist, thing is signal through tv is great but not through pvr. Looking further into the tuners the tv has better capability when dealing with poor signal strength so would replacing the cable with double shielded cable and potential better positioning of aerial be adequate. Putting it outside would prove to be expensive and would rather keep costs down.
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Dave's: mapD's Freeview map terrainD's terrain plot wavesD's frequency data D's Freeview Detailed Coverage
Dave sharp: Yes, you should use satellite-grade coaxial cable to preserve the signals.
Also, with switchover happening very shortly, the signals will be considerably better by 15th (Craigkelly) or 22th (Black Hill) June 2011.
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Brian Whittington8:01 PM
I am having problems with my tv. the digital channel keeps freezing, the analogue reception is also bad. any ideas of the cause. we had some heavy winds and heavy rain since last Sunday 13 Feb 2011. any help would be appreciated.
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Brian Whittington: Please can you see the list of suggestions on the Freeview reception has changed? | ukfree.tv - independent free digital TV advice page?
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Kevin8:56 PM
Swindon
Postcode is SN40NW (Butts Rd). Fringe(ish) reception on Mendip, Oxford and Salisbury. Often drop one or two channels all together when retuning (Film4 and Film4+1 are usually first to go) and blocking and freezing quite often on others especially in poor weather but not always weather dependant but I do realise weird atmospherics can effect things even when weather (for us humans) is good.
Aerial is pointing at Mendip rather than Oxford as 24months ago (when installed) this gave best reception.
Humax PVR9150t (with latest software updates) is used for all reception with nothing on output of PVR pass-through and TV connected via scart. TV tuning (Samsung LE26R pulls far less channels and less reliable than PVR)
I have followed your retuning guides with no improvement.
Will moving it to Oxford now or a better aerial get me reliable reception? Current aerial is fairly standard digital wideband yagi.
FWIW signal (via Humax built in meter) on Film4 is strength 55% and quality flickering 40 - 80%
BBC1/Channel4/ITV (all) strength 78% and quality solid 100%
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Kevin's: mapK's Freeview map terrainK's terrain plot wavesK's frequency data K's Freeview Detailed Coverage
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Dave sharp10:34 PM
Anstruther
Cheers briantist will get some from screwfix tomorrow and give it a go then take it from there
Cheers
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Dave's: mapD's Freeview map terrainD's terrain plot wavesD's frequency data D's Freeview Detailed Coverage
Tuesday, 22 February 2011
Kevin: Basically, no.
You will get better reception from Mendip, but only until April, when the shifting changes caused by switchover will start to degrade the reception from there.
Your Oxford reception is also going to get worse from April too.
If you are going to spend any money, I would recommend you get a Freesat HD box and dish, and use this to fill in your reception holes until 2012.
At some point in 2012, as switchover is finished in the UK, you will get a great Freeview service again.
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Kevin10:46 PM
Brian,
Thank you for your reply even if it was, sadly, as expected; no criticism meant just recognition of frustration caused by the fringe and overlapping areas I live in.
As current aerial is on standard 75ohmn aerial cable (less than 5 years old) rather than satellite grade would changing to satellite grade and use the XB22WB (with masthead amp? - Humax has masthead amp power as built in) or diplex two good quality narrower band aerials give reliable reception or am I just so far away and it's signal noise rather than strength that is the problem. (Yes I have been doing some reading at www.aerialsandtv.com.)
Costs of my above suggestions are getting very close to HD Freesat + Satellite installation and as Humax PVR9150T isn't HD your original suggestion about going Freesat may still be the best solution!
If I stick with existing setup just how bad will things get after April?
Note channels - strength - quality tonight are:-
24 - 77 - 100
27 - 77 - 100
56 - 63 - 100
62 - 60 - 100
67 - 60 - 100
and Film4+1 still not tuning!
That's added a little confusion and possible option. BBC1 is on Ch27 and ITV is on Ch24 so that means it's picking up the Chiseldon repeater. Whilst this transmitter is vertically polarised it is only 100yds away so no surprise really!
Does that add weight to the suggestion of high quality aerials diplexed. Cost may still shift the balance to Freesat though but my thoughts are repolarise existing aerial to vertical further improving Channels 24 and 27 and then buy a high quality C/D aerial (plus masthead amp?) and target Mendip with that.
You may have guessed that I am reluctant to go Freesat as I just don't like the look of those darn dishes - weird maybe but that's my view.
Finally, if it's worth noting, I am also getting weak BBC1 etc on Ch34
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