Freeview Box

[dillon]

Thanks for last quick response - My digibox is showing all channels except all ITV and channel 4 channels where the picture is breaking up - I have bought a new one but it is doing the same. We have just installed another fairly big TV upstairs in the house. Could this be draining or affecting the signal?

[WhiteBear]

if u r using the same areil ...--i.e. splitter throughout thehouse then yes maybe, u ,may need a Booster.

i live in a block of appartments.. normally my signals are fine, lately more ppl have moved into my block and the signals have been really poor, so i had to get a booster to get all the channels.

have u tried adjusted your digi box?? x

[vehelpfulguy]

Please dont put things like this in as a new question.

Jusy reply to your original question

[Buenchico]

I promise not to bore you with loads of 'techie theory' about signal-splitting and standing waves but both adding a new device (TV, digibox, DVD recorder) and subtracting an existing one from a system can adversely affect the signal strength so, yes, it's possible that the new TV may be a factor.

However, the previous reply was completely correct in diagnosing the prime cause of your problem as insufficient signal strength from your aerial. In a technically perfect world, every TV aerial would be perfectly matched to the signal of the incoming frequency of the channel you want to watch. The problem is that you'd need a different aerial for every single channel! So all TV aerials can only offer a 'compromise solution', which means that they're better matched to some channels than to others. (I've also seen a post, here on AB, which said that the ITV and C4 channels use a different type of encryption to others, requiring a slightly stronger signal strength. That would certainly explain why it's usually those channels which people have difficulty receiving).

First, step outside a check that your TV aerial is still pointing in the right direction. (A battering from our wonderful British weather can often lead to problems).

Assuming that your aerial looks OK, try adding a simple signal booster. (From larger branches of Tesco, Asda, etc, or from Maplin Electronics). That might well be enough to fix the problem. (You won't really know until we get some heavy rain or snow, when signal strengths are at their weakest).

If a booster doesn't work, upgrade your aerial system by replacing both the aerial and (just as important) the cable. This 43-element aerial has been widely praised by AB contributors:
http://www.maplin.co.uk/module.aspx?moduleno=2 2523

Chris

[Buenchico]

For Captain Kirk:

It's tempting to think that if you split a cable you'll only get half the signal down each side. In fact, the attenuation is far less than you might expect. (You only lose a small percentage of the signal strength).

However, the ability of radio signals to penetrate solid obstructions becomes markedly reduced as the frequency rises. So low frequency signals (e.g. 'Long Wave' radio) can easily be picked up anywhere inside a house, as can medium frequency ('Medium Wave') radio signals. High frequency ('Short Wave') and very high frequency (VHF/FM) signals can be picked up indoors but with greater difficulty than lower frequencies. By the time you get into ultra high frequencies (which are used by digital TV) the amount of attenuation caused by a roof structure is very high.

At a rough guess, I'd reckon you'd lose about 5% of your signal strength by splitting your cable (which could be overcome by using a booster, if necessary) but at least 50% of your signal strength by putting the aerial in the loft. A splitter is the simpler, cheaper and far better option for you.

Chris