Analogue and digital signal strength
Brian Butterworth published on UK Free TV Many people ask why they can receive an OK analogue picture, but need to upgrade their aerial to get Freeview, or sometimes get perfect Freeview reception when the analogue picture is very poor.
The digital signals are currently broadcast at low power (this will change as switchover happens) to prevent interference with the existing analogue signals. Thankfully most Freeview boxes can work with these weak signals. The following list shows the strength of the digital signal compared to the analogue for the 80 Freeview transmitters.
Expr2
Aberdare: 15%
Angus: 2000%
Beacon Hill: 1%
Belmont: 1.43%
Bilsdale: 1.15%
Black Hill: 4%
Blaenplwyf: 1.66%
Bluebell Hill: 8.88%
Bressay: 10%
Brierley Hill: 1.22%
Bristol Kings Weston: 4.5%
Bromsgrove: 1550%
Brougher Mountain: 0.5%
Caldbeck: 0.82%
Caradon Hill: 0.76%
Carmel: 2%
Chatton: 4.16%
Chesterfield: 1.8%
Craigkelly: 2%
Crystal Palace: 2%
Darvel: 2%
Divis: 0.49%
Dover: 1%
Durris: 2%
Eitshal: 0.8%
Emley Moor: 0.93%
Fenham: 1%
Fenton: 0.5%
Guildford: 1%
Hannington: 4%
Hastings: 18.3%
Heathfield: 1.2%
Hemel Hempstead: 2%
Huntshaw Cross: 3.66%
Idle: 2%
Ilchester Crescent: 4%
Keelylang Hill: 1%
Keighley: 0.91%
Kilvey Hill: 3.83%
Knock More: 1%
Lancaster: 1.83%
Lark Stoke: 416.66%
Limavady: 0.8%
Llanddona: 1%
Malvern: 10%
Mendip: 1.83%
Midhurst: 1.25%
Moel-Y-Parc: 0.41%
Nottingham: 1.85%
Olivers Mount: 9.1%
Oxford: 1.6%
Pendle Forest: 18.2%
Plympton: 9.15%
Pontop Pike: 1.93%
Pontypool: 6%
Presely: 0.83%
Redruth: 1.85%
Reigate: 1500%
Ridge Hill: 2%
Rosemarkie: 10%
Rosneath: 2%
Rowridge: 4%
Rumster Forest: 1.33%
Saddleworth: 1.8%
Salisbury: 6.9%
Sandy Heath: 1.83%
Selkirk: 6%
Sheffield: 1%
Stockland Hill: 1%
Storeton: 2550%
Sudbury: 2.01%
Sutton Coldfield: 0.8%
Tacolneston: 2.66%
The Wrekin: 1%
Torosay: 0.62%
Tunbridge Wells: 1%
Waltham: 1.8%
Wenvoe: 1.16%
Whitehawk Hill: 3.67%
Winter Hill: 1.83%
4:47 PM
I have just been to my local Maplin and they advised me not to buy a set top aeriel as they said it would not work on Freeview in our area. Our area is not listed as low strength signal (Sidcup). This is for a second TV which now has inbuilt freeview. The one attached to the roof aerial uses a freeview box. Not keen to wire up every tv to the roof! No point in linking all TV's as you might as well go back to sitting in the same room because you can only watch what is selected on the main tv.
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J: They are correct, indoor aerials are unsuitable for Freeview reception.
If you connect the existing rooftop aerial to all your sets, you can use a Freeview box on each to watch whatever channel you want.
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5:46 PM
J
Maplin may well be correct, but we can get a usable signal in one room (which has a big window in the right place) with an indoor ae and a cheap amp. - which none of the predictors say we would be able to.
Also, has your region switched over yet. Digital strength will rise when analogues goes off.
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6:39 PM
Reading
Steve: the problem is that the received signal level naturally varies over time, due to the changing weather conditions.
Because the indoor aerial is much lower in height it's blocked more by neighbouring buildings, and picks up more reflections from them, as well as reflections within the building. It tends also to have poorer gain, front/back ratio and cross-polar rejection compared to a roof aerial, meaning it picks up less of the signal you do want and more of the interference you don't want.
Amplifiers can never correct for picking up unwanted signals, they amplify unwanted signals just as much as wanted ones, and they add extra noise and distortion of their own. An amplifier might help if the signal level from the aerial is actually weaker than the minimum the TV or box needs, but generally they're harmful.
As I said, the signal level from any transmitter - and this includes unwanted signals - varies over time. The prediction is done on the basis that you will get problem-free reception 99% of the time. That's still over three-and-a-half days - 87 hours - per year. You might get good reception with an indoor aerial some of the time, but you'll get a lot of interruptions too.
Because most TVs and set-top boxes don't show the signal AND the noise level, only a raw signal strength, it's really not possible for the average user to work out the best site for an aerial.
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Mike's: mapM's Freeview map terrainM's terrain plot wavesM's frequency data M's Freeview Detailed Coverage
7:55 PM
I live in the Darvel - 2% area.
I have two JVC LT32DE9BJ 32" Hd Ready Lcd Tv with Integrated Freeview. Recently both have stopped recording tv programmes when they are in standby mode. They will record if tv is actually switched on. This has only been happening over the last 3 or 4 months.
I have a Sagem box wired through one of these tv's and it records everything !!!
On checking my TV signal; strength 67% & quality 100%.
Anyone any ideas what is happening - TV's have no fault one has been for repair and sent back - no fault.
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will morton: You wouldn't normally expect to do that, a Freeview+ box has it's own tuners so you don't need to have the TV on.
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3:11 PM
I have just purchased a new Samsung tv but it will not auto tune because it says weak or no signal on the screen, however we have two existing tv;s that run perfectly well, one without an amplifier & one with. Does a new tv require a stronger signal? we have tried all of the different configurations without success, any ideas or suggestions or explanations would be greatly appreciated.
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K tasker: You might start by removing your booster. You should get all seven multiplexes, including the HD one from the Crystal Palace transmitter, assuming you have a rooftop aerial.
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11:46 AM
We are moving to Cyprus and I know that they broadcast terrestrial analogue local channels and will continue to do so for the foreseeable future.
We are taking our UK TV with us, recently replaced, which unlike its predecessor does not appear to be able to tune to analogue channels (not needed in UK now I appreciate)My question is, will the digital tuning facility be able to tune into analogue signals in Cyprus?
We will almost certainly use Sky when there, the but the local channels are sometimes worth watching
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12:23 PM
Wrexham
alan - absolutely not!
And I don't think you can get boxes to do analogue tuning.
Sounds like a swap with someone with a decent analogue TV would be best.
Do check that Cyprus TV is entirely compatible with UK. There can be variations in things like sound separation.
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steve's: mapS's Freeview map terrainS's terrain plot wavesS's frequency data S's Freeview Detailed Coverage