A Guide to Digital TV (Buyers Guide: Televisions)

Member Name: lordpercy

Product:	Buyers Guide: Televisions
Date:	23/01/01 (3161 review reads)
Rating:

Advantages: Clearer pictures, many more channels

Disadvantages: Set top technology keeps changing!

The Digital revolution is upon us! Well that's what the man at Currys told me when he tried to sell a new all in one TV and satellite decoder and very convincing he was too!

But luckily I've seen most of the developments of digital TV from the inside, no I haven't been to Parkhurst I mean the inside of TV.

Digital TV has been with us for many years with the first domestic digits coming via D2Mac a system that never quite found favour with the Sun reading masses, right the way up to present day and the battle between Sky and On Digital.

So what exactly is Digital TV? And why bother switching after all my TV picture is fine, isn't it?

Before you can understand Digital TV you first have to get a grip of the existing system of analogue transmission. The TV pictures and sound are modulated onto a carrier wave (or TV signal) this wave is an analogue signal and can be disrupted by interference or bad weather. This disruption to the signal leads to the loss of information that makes up the picture you and I watch.
However Digital TV works on the same basic principles as the domestic CD player or any other digital signal, data is sent as packets of 1's and 0's which are also put on a carrier wave which is beamed to your home.
The vital difference is how the information is encoded and the effect it has for ordinary punter like you and me.

Imagine a man standing on a hill way off in the distance he has 20 semaphore flags which he uses to send a message to you, this is fine on a clear day but on a cloudy day it can be very difficult to tell if he is waving a red flag or a red flag with poker dots. This is the equivalent to the analogue system with lots of information being sent by varying the carrier wave thousands of times per second.

Now if our chap on the hill had only one flag and held it up to represent 1 and down to represent 0 it would be very easy to see what he was sending whatever t
he weather. This can be done hundreds of thousands of times per second and so the same amount of information can be sent as in the analogue system.

But the bit that matters to you and me is that the data sent using a digital signal is far more robust and is generally either on or off a bit like a Duracell battery, so if you can receive digital then it going to be good quality.

Ok so you now have a grasp of Digits, so what else makes it such a panacea for the viewing public?

Well the obvious difference is the number of channels available on digital platforms compared to the analogue system. This is achieved by the use of compression, a few years ago a well known national broadcaster held a meeting to discuss the future of TV broadcasting in the UK.

They already had 2 channels on air (guessed who yet?) and wanted to decide how best to use the space in the digital era.

They had a choice of 4 options.

1. To transmit 2 High definition, wide screen channels (without question the best quality available)

2. To transmit 4 Wide screen channels with surround audio.

3. To transmit 8 Channels of equal quality when compared to their 2 existing channels.

4. Or 30 channels of compressed TV Signals (SVHS quality).

Ok so which did they choose? Well let's just say your auntie will be providing many more channels in years to come.

So is this bad news? Well not really after all you will have many more channels to choose from but they will be of a poorer video quality than HDTV.

So given the fact that Digital TV is here what do you do as a consumer, the government has announced that analogue TV will be switched off by 2015 but the leading TV companies are pressing for this to be brought forward to 2010.
Therefore you will have to migrate to Digits sooner or later and at the moment the choice is between Sky and On Digital, the decision between them is simple with Sky you nee
d a dish and with On Digital you should be able to use your existing aerial.
I say, "should" because it is quite common for aerials to require an upgrade to get a good signal and that means a hidden cost.

I’m not going to tell you which way to jump as that is a personal decision for you to take based on what channels you want to receive, but I do have some words of warning as regards to set top boxes.

The box manufacturers have designed a system that is very robust and provides excellent features in a very compact unit, but to achieve this they have used a very proprietary format that is very difficult to upgrade.

The boxes all handle MPEG2 data which is the current broadcast format but MPEG4 is on its way and can be seen on the web already, then MPEG7 and also MPEG21, don't ask who numbered it! Sadly the box you buy today is not re-programmable like a home PC you can't just load up a new operating system or download a patch I'm afraid its back to Currys again in 2 years time.

The cynic in me says this was the plan all along but I think they just hadn't appreciated how quickly the web would push video technology along.

So what do you do? Well you want a box right? Don't fret go and buy a nice Pace box and look on it as a two year investment.
DO NOT! Take the man in Currys advice and buy an integrated decoder and TV other wise you will have to ditch your telly as well.

Digital TV is a vast improvement over the analogue system and like it or not the government will switch off the analogue signal in the next ten years, so don't wait too long and miss out on the wealth of TV that is now available.

But the caveat "buyer beware" has never been more relevant, think about the future and look at the pace of change within the PC market because your humble telly is being sucked into the same technological whirlpool.

Don't buy integrated systems
no matter how nice they look as you will be upgrading them soon and don't expect the greatest picture quality as the decision was taken for you many years ago. But dip your toe in the water and spend time reading the reviews of TV's and Decoder's on DooYoo they'll put you in good shape for the digital revolution.


Lordpercy ©2001

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