Analogue TV and Digital TV Explained
From June 2010 through to 2013, Analogue TV is being turned off in Australia in favour of Digital TV. This article aims to tell you in simple terms what this means and what the differences are for you and the equipment you have.
Analogue and Digital Transmission is a way of sending lots of information - 'data' in the form of sound or sound and vision to a device that can 'decode' it, or 'translate' it out of what is simply 'electricity' sent through the air and into something we understand - such as Television in this example.
Analogue is what we're all historically used to whether you know what it means or not. In it simplest form, imagine 2 people holding a bit of rope about 10 meters apart... one person waves their arm up and down whilst holding the rope and a wave travels down that rope and if you keep doing it, the waves continue... the longer the distance the harder it is to send a wave to the other end and so you have to really wave the heck out of that rope to make the wave get to the other end. Imagine inside that wave in the rope itself, you have your TV signals... at close range, they get from A-B easily but further away, they get blurry. We've all had that with our TV's right? Lots of noise on the screen, can't quite tune to that channel? Weak reception. The same applies to normal radio.
The advantage of Analogue TV used to be that the signal can be sent further more easily, so used to be suited to long distances before the 'digital age' enabled the same far more efficiently.
Now imagine the same 2 people. Substitute the 'rope' in the last example for simply being able to see each other. If they can both see each other, call that a '1' (on) for being able to see each other. Is either 1 of the 2 cannot see the other. - call that a '0' (off). That's digital transmission.
With Analogue there is no clear boundary between on and off... there's just a fuzzy zone as the signal weakens. With digital, it is simply 'working' or 'not working'... 1 or 0. There is no in between. So, if the digital signal reaches you, it is as perfect as it can get regardless of how strong the 'signal'.( This is a little simplistic yes as you can indeed receive a 'weak' digital signal, but the same still applies - the signal will either work or not work... no fuzzy bit in the same way as Analogue) The channel is either perfectly clear on your TV or it is not there at all. There is no blurry or fuzzy, or noisy with Digital.
Sometimes you might see a pause on your screen, or a bunch of weird coloured squares pop up, and maybe some weird squeaky sounds and then the picture returns... - this happens when the signal isn't quite strong enough... most of the time though, this is actually what is being 'sent' from the other end and then broadcast to you. TV companies, especially in live broadcasts, use very high tech digital transmission to send a live picture from a football field, for example or from an F1 Car to a TV Truck closeby where they assemble the images and send them via satellite to you. IN this chain, there's lots of chances for a signal to be interfered with on its way to you, so often, the little glitches are in fact not at your end.
Analogue and Digital Transmission is a way of sending lots of information - 'data' in the form of sound or sound and vision to a device that can 'decode' it, or 'translate' it out of what is simply 'electricity' sent through the air and into something we understand - such as Television in this example.
Analogue is what we're all historically used to whether you know what it means or not. In it simplest form, imagine 2 people holding a bit of rope about 10 meters apart... one person waves their arm up and down whilst holding the rope and a wave travels down that rope and if you keep doing it, the waves continue... the longer the distance the harder it is to send a wave to the other end and so you have to really wave the heck out of that rope to make the wave get to the other end. Imagine inside that wave in the rope itself, you have your TV signals... at close range, they get from A-B easily but further away, they get blurry. We've all had that with our TV's right? Lots of noise on the screen, can't quite tune to that channel? Weak reception. The same applies to normal radio.
The advantage of Analogue TV used to be that the signal can be sent further more easily, so used to be suited to long distances before the 'digital age' enabled the same far more efficiently.
Now imagine the same 2 people. Substitute the 'rope' in the last example for simply being able to see each other. If they can both see each other, call that a '1' (on) for being able to see each other. Is either 1 of the 2 cannot see the other. - call that a '0' (off). That's digital transmission.
With Analogue there is no clear boundary between on and off... there's just a fuzzy zone as the signal weakens. With digital, it is simply 'working' or 'not working'... 1 or 0. There is no in between. So, if the digital signal reaches you, it is as perfect as it can get regardless of how strong the 'signal'.( This is a little simplistic yes as you can indeed receive a 'weak' digital signal, but the same still applies - the signal will either work or not work... no fuzzy bit in the same way as Analogue) The channel is either perfectly clear on your TV or it is not there at all. There is no blurry or fuzzy, or noisy with Digital.
Sometimes you might see a pause on your screen, or a bunch of weird coloured squares pop up, and maybe some weird squeaky sounds and then the picture returns... - this happens when the signal isn't quite strong enough... most of the time though, this is actually what is being 'sent' from the other end and then broadcast to you. TV companies, especially in live broadcasts, use very high tech digital transmission to send a live picture from a football field, for example or from an F1 Car to a TV Truck closeby where they assemble the images and send them via satellite to you. IN this chain, there's lots of chances for a signal to be interfered with on its way to you, so often, the little glitches are in fact not at your end.
A really important thing to recognise here is that certain Hi-Fi stores will take advantage of you when you buy anything related to home cinema, digital TV and the like telling you that for the best signal, you need expensive, special cables... and they are very expensive. Total and utter rubbish. The cheapest cable you can get your hands on providing it is not broken will do the job just the same as a super-expensive cable would. Before digital signals, expensive cables were indeed needed so that the could transfer the analogue information as efficiently as possible to reduce 'noise'... As we discussed above, digital is either 'On' or 'Off'. The cable in between is largely irrelevant to the equation.
I could go on much more about this - High Definition / 3D TV etc etc,. but wont.. I think the distinction is pretty clear above for the purposes of simplicity!. Feel free to leave comments here if you'd like additional questions answered using the 'Comments' facility just below on this page.
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I could go on much more about this - High Definition / 3D TV etc etc,. but wont.. I think the distinction is pretty clear above for the purposes of simplicity!. Feel free to leave comments here if you'd like additional questions answered using the 'Comments' facility just below on this page.
Back to ZeroThree