Scarts and spectrums, what's it all about? The UK-wide digital switch-over is nearing completion but are you all set? Channel 4 News answers the key questions.

Q+A: Still confused by the digital switch-over?

The digital TV switch-over is the process of turning off the UK's analogue TV signal and replacing it with a digital signal. So what does it mean for you and your TV? Here are the key questions and what you should know.

Will my old TV set become useless?

No, most existing TV sets can be easily converted to digital by using a set-top box (see below), even old black and white sets. If your existing TV has a Scart socket, you need a digital box with a Scart socket. If there is no Scart, you need a box with an an RF modulator - this is a device that enables TVs with only an aerial socket to receive channels again after the switch-over.

How do I choose a set-top box?

There are lots of options and it can be confusing. You could choose a one-off payment service or a monthly subscription. The price of a Freeview box starts at around £25. This one-off cost will get you up to 48 channels - and once you've plugged in, these channels are free. The more expensive boxes have extra features, like recording facilities. Freesat is similar, except it works via a satellite dish, not an aerial. It's worth noting that many TV sets now have an in-built Freeview receiver. This means less cables and sockets because your receiver and screen are all inside the same piece of hardware.

The are many subscription options for digital TV - ranging from Sky packages to Virgin Media, BT Vision and Top Up TV. For full details of the choices available, you can download a PDF file, below.

Click for more details - National Switch-over
Q+A: Still confused by the digital switch-over?

Do I need a new TV aerial?

If you currently have good reception on your TV, it's unlikely you will need to replace your aerial after switch-over. However, where you live could be a factor and you may need what is called a "wideband aerial". You can find out more about your region and this type of aerial here. If you have a satellite or cable service on all the TV sets in your home, you don't need an aerial.

Will my video or DVD recorder still work?

Your video or DVD recorder will still be able to play video tapes or DVDs and record digital TV programmes. However, unless it is a digital recorder, it won't be able to record TV programmes on one channel, while you are watching another.

I've already gone digital and the picture sometimes breaks up - why?

Electrical interference can cause picture break-up, freezing, or clicking sounds. Try leaving the TV on and switch off or disconnect your electrical appliances one at a time to see if it stops. The weather can also cause problems with your digital signal because of "atmospheric pressure". The technical term is the "inversion effect": as the sun heats up the ground, warm air gets trapped underneath the colder air higher up. At the point where the warm air gets trapped under the cold air this creates a layer that "mirrors" television signals. This can cause significant interference for Freeview viewers with a weak signal. Retuning your box can help and work is under way to strengthen the signal.

Q+A: Still confused by the digital switch-over?

Hang on, you haven't said why we need the switch-over in the first place...

At the moment it takes a lot of airwave space to broadcast the five terrestrial TV stations - BBC1, BBC2, ITV, Channel 4 and Five - using analogue technology. Digital technology can compress all of that video to a much smaller amount of airwaves, freeing up what is called "spectrum" space. So what happens to this freed up space? Well, the government is selling it off to use for "4G" or the fourth generation mobile systems. This could be a nice little earner. But the official reason? More choice for TV viewers. You can read more from our Technology Correspondent Benjamin Cohen here: The real reason behind the digital TV switch-over

So what exactly are the benefits for me?

With digital TV, you can enjoy the five traditional TV channels as normal - plus quite a few more.

Most households will be able to receive around 40 channels, with all areas getting around 20 of the most popular channels such as ITV2, E4 and BBC Three. So there you have it. Happy channel hopping!