‘Basics’ Category

 

Buyer beware: Freeview HD bargains aren’t always what they seem

Freeview HD is a brand new technology and like most of those, it comes with a price tag attached; when I recently looked at set top boxes, most came in at over £100, with some costing up to £170. When you’re used to the incredibly low prices that a standard definition Freeview box can be found for, it’s not surprising that many people are hunting for bargains, or complaining that the price is too high for HD.

It’s instructional to remember that when the first Freeview (or OnDigital as it was then) boxes appeared, they cost an awful lot too, until OnDigital joined Sky in giving away free boxes with a subscription. Now a better featured receiver is much, much cheaper those those first boxes, and the same will happen with HD – probably even faster.

Not everyone can be patient, and it’s no surprise that people are turning to sites like eBay in search of bargains. And having seen questions on AVForums regarding one potential bargain, I though it prudent to remind people to check carefully what they’re spending their money on.

A quick search for ‘Freeview HD’ on eBay turns up plenty of products. Some of them are indeed what you’ll be looking for, but there are equally plenty that won’t, and that you need to be careful about.

Check the specs

First, there’s the problem of what you search for. Type in ‘Freeview HD’ and you’ll see plenty of TV sets turn up with that in the description; look more closely though and they’re ‘Brand X Freeview HD Ready TV’ – and you really need to imagine a comma between ‘Freeview’ and ‘HD Ready.’ As I’ve mentioned before, ‘HD Ready’ means that a set can display an HD picture, from an external source, and these are typically HD Ready sets, that have a Freeview tuner, which will only be standard definition, rather than a built in Freeview HD tuner.

Worse still, I found two auctions for products described as ‘Freeview HD’ which clearly are not.

One was a Philips DTR 5010 set top box, and the other was a TV tuner for in car entertainment systems. Both can indeed decode high definition pictures that use the H.264 codec. But what neither will do is tune in to the UK’s high def broadcasts in the first place, because they don’t have the DVB-T2 tuners necessary.

That, in short, is what you need to check for; the UK Freeview HD system uses brand new DVB-T2 technology, not the DVB-T that’s used for HD in other countries. If you don’t see it on the specification sheet, then it almost certainly isn’t there, and the receiver will only pick up HD channels in other European countries that use the older system.

Another thing you can check for, if you want to be sure, is the ‘QAM’ types listed on a spec sheet, which is one of the parameters of the digital broadcast; standard def services in the UK use QAM16 and QAM64; sometimes the number is listed before, like 16-QAM. Freeview HD, as part of the DVB-T2 system, uses QAM256. No mention of either DVB-T2 or QAM256 is pretty much a dead giveaway that the product you’re looking at is not capable of receiving Freeview HD, and you should walk away because it’s not the bargain that you were hoping for.

And while I have your attention, remember that there’s no such thing as an HD aerial.

 
 
 

Freesat and surround sound

If you’ve got a Freesat HD box, and want to listen in surround sound when you’re watching HD programmes like Dr Who or Damages, then you’ll be glad to know things are pretty straightforward.

Those who aren’t familiar with surround sound should first check out the first part of this feature, for the background information. Up to date with that? Great.

Good news for Freesat viewers:  you’d have to look very long and very hard to find a surround decoder, whether standalone or built into an AV Receiver or AV Amplifier, that didn’t understand Dolby Digital, which is what’s used on the Freesat HD channels.

The quick summary: if you don’t have a surround decoder with HDMI sockets, just connect the Freesat box to the TV via HDMI, and then use an S/PDIF digital connection to link the receiver to your surround decoder for Dolby Digital 5.1 channel surround.

When you’re shopping, making sure that you buy a Freesat HD box with a digital audio connection that matches the ones on your surround decoder, if it doesn’t have both optical and co-axial inputs.

If your decoder has HDMI (most recent AV amplifiers/receivers), connect the Freesat box to the decoder with an HDMI cable, and the TV to the ‘TV out’ HDMI connector on the decoder.

In both cases, hook up the speakers, and you’re now ready to enjoy surround sound from your HD channels. Switch to a non-HD channel, and the receiver will usually switch to PCM stereo, and you’ll hear that through your front speakers, automatically.

And really is all there is to it. If you’re interested in surround from Freeview HD, the next part of this feature explains what you need to know (and it’s a bit more complex).

 
 
 

Surround sound explained

One of the things that goes with high definition TV, as far as many people are concerned, is surround sound. If you’re watching a film or a great drama in high def, then adding 5.1 sound makes the experience even better.

But if you don’t shop wisely, you may find that you don’t get the experience you expect. I’m going to explain why, to help you make sure you make the right choice.

First, what is surround sound anyway? What’s all this 5.1 stuff? Well, normal standard definition TV in the UK is just stereo, with a left and a right speaker. Surround sound is described as 5.1 because there are five main channels, plus one extra. That’s left and right at the front, left and right at the rear, a centre speaker (traditionally under the TV, for the voices), and the extra channel is the ‘sub woofer,’ which is for the deep chest rumbling bass noises, like explosions, passing trucks and so on.

You don’t have to have all those speakers – I have a great pair of left and right front speakers for example, and they produce all the bass I need, so I don’t have a subwoofer, nor do I have a centre speaker; my surround decoder is set to split the centre channel between those two instead.

And there I’ve just introduced another element – the ‘surround decoder.’ This is a bit of kit that takes the digital information from a broadcast (or a DVD, or BluRay) and decodes it, sending the right information to each speaker. You can buy an ‘AV Amplifier’ which includes a surround decoder, or you can buy a separate decoder to add to an existing hifi system (though there aren’t many available these days, and they tend to be expensive). Other alternatives are AV Receivers, which are like AV Amplifiers, but with a radio built in, and all-in-one gadgets from some companies like Panasonic and Yamaha.

These tend to take the form of a ‘sound bar’ which is a long box to sit under the TV, with the electronics and centre speaker, and then satellite speakers to go around the room.

Some sound bars, and some TVs too, include ‘pseudo’ surround modes, which try to create the same effect, but without extra speakers and wires, by bouncing sound off walls, or using fancy digital effects to trick your ears. But, in my view, they’re never going to really match up to having all those speakers positioned around your living room.

OK. Now, we’ve got a surround decoder, we’ve got speakers, and we’ve got something that produces surround sound – a BluRay player, or a high definition receiver. All set? Not quite.

Surround formats

Now, we get into the tricky world of formats. When it comes to surround sound, the name most people associate with it for home systems is Dolby Digital, which is also known as AC3, and sometimes when people say ‘5.1 surround sound’ they’re assuming Dolby Digital. Turns out that’s not always a good assumption.

Some DVDs use a system called DTS instead, and there are newer versions of Dolby and DTS used on BluRay, which can have seven main channels; but you don’t need to worry about that for high def broadcasts.

What you do need, however, is to make sure that your surround decoder understands the information from the HD source you’re watching. So, if you have a decoder that only works with Dolby Digital then you have to make sure that that’s what you feed it. It won’t make sense of anything else; that’s why some BluRay players have ‘downmix’ or ‘downconvert’ options, allowing them to convert, for instance, the 7.1 surround sound on the latest discs to 5.1 Dolby Digital, so even if you have older kit, you can still get the effects.

There’s one other thing to note – most surround decoders will also understand a format called ‘PCM’, which is just a digital version of stereo.

Making the connection

Where are we now? Take an HD source, like BluRay or an HD receiver, connect it to a surround decoder, and then you get great effects through all the speakers. So, how do you connect it?

There are a couple of ways. Most people will be connecting their BD player, Freeview HD box or Freesat box to a TV via HDMI. And then what? If you want surround sound, you’ve got to get that out of the box too, unless your TV happens to have a surround or pseudo-surround mode, and you’re happy with that.

If not, the way lots of people do it is via a digital audio output on the box – most of them have at least one; it’s either an optical connection (you can usually tell from the glow coming from the socket), or an electrical one (often referred to as ‘co-axial digital’). Some have one or the other, some units have both, and the generic term is “S/PDIF” after Sony and Philips who came up with it.

Just about every surround decoder has several S/PDIF inputs, so you connect the HD box or player to the decoder this way, hook up the speakers, and you’re done – as long as the box is sending a signal your decoder understands. Many decoders will have connections for the video too, acting essentially as a switchbox.

Some more modern surround decoders (and especially recent AV Amplifiers and Receivers) also have HDMI sockets. The idea is that you connect all your HD bits of kit to the AV amp via HDMI, and then a cable goes from the amp to the TV. So you get a single cable for each device, sound and vision are both switched by the AV amp, and you use its remote control to select what you want to watch, and how loud it is – all very neat and straightforward.

So, now you know the basics of what surround sound is, and how to hook it up. In the next two parts, I’ll look at exactly what you need to do to get surround sound from your Freesat or Freeview HD box.

Next: Freesat and surround sound

Part 3: Freeview HD and surround sound

 
 
 

Set up your TV for HD

This article was originally published on RegHardware in August 2009 and has been updated for Gone Digital.

Back in the old days, when you bought – or rented – a television set, there was a pretty good chance that someone would deliver it, set it up, and tune it in for you. And there was a very good chance that when they did that, they’d be able to find a channel broadcasting a testcard without much difficulty, and use that to make sure all the picture settings were correct, or at least not completely wide of the mark.

If you’re buying a new TV to get the best out of services like FreeviewHD and Freesat, things are pretty different. Unless it’s coming as part of a high end AV installation, chances are you’ll be unpacking it yourself, and trying to make the best job of setting it up to give the brilliant picture that the reviews raved about. So, just how do you do that, then?

When you see a TV set in a typical showroom, it will have been set up to produce vivid, eye-catching colours, and to look fairly reasonable under the harsh fluorescent lighting. A typical living room will have rather more subdued lighting, and for a more realistic picture, you may well want something rather less vivid.

There’s a huge range of settings on some modern sets, and even just the basic options can be easily misunderstood. So, just how do you set up your new flat panel to give the best picture possible?

One answer is to have it professionally calibrated – and if you have the cash to spare, then for upwards of £2-300 you can have an ISF calibrator visit your home and set the TV up for you. Prices vary, and you can expect to pay more for each input that you want set up. An ISF technician will access the hidden service menus on a TV and use a colorimeter to make sure everything is set up more accurately than you’ll be able to do it with the naked eye. Is it worth it? Plenty of people think so, but the cost will rule it out for many. I’m going to look at some of the DIY alternatives; they may not be quite as accurate, but you can still improve the picture, without breaking the bank.

First catch your test card

Before delving into the nitty-gritty, what do you need to set up? Firstly, you probably don’t want to spend hours tweaking a brand new panel – wait a few weeks, until it’s been used a fair bit, and then tweak. Remember that for the best results, you’ll have to set up the picture for each input that you’re using, if the TV remembers per-input settings. You can’t assume, for example, that a signal fed from a DVD or Blu-Ray player via HDMI will be treated in the same way as one from a SCART, or a memory card reader.

Fortunately, the switch to flat panels does mean that display setup doesn’t involve worrying about geometry – aside from stretch effects applied to non-widescreen programming, you don’t suffer from some of the more annoying issues of a CRT, like circles being out of shape. It’s largely a matter of making sure black and white are set up properly, and then the colours adjusted, in that order. You can then adjust some of the other options, such as ‘sharpness’ and tinker with any additional features the set provides such as noise reduction or frame interpolation, though as a rule any ‘enhancement’ or ‘noise reduction’ options are best turned off.

To set the screen up, you’ll need patience, and test patterns. And you need to do it in the same sort of lighting as you’ll be viewing the TV. Lighting an patience are easy; what about the test patterns?

You can buy a test DVD or BluRay, like Digital Video Essentials, which will set you back less than £20, but in fact you don’t even really need to spend that much, as test signals – for HD at any rate – are widely available online.

If you do want to get Digital Video Essentials, click this link to buy it from Amazon: Digital Video Essentials – HD Basics [Blu-ray] [2008]

For free patterns, it’s worth registering on the US-based AVS Forum. Once you’ve done that, you’ll be able to download disc images that can be burnt to a BluRay or DVD and used in your BluRay player, together with detailed instructions.

Another source of test screens is the test images that are included on many Sony BluRay releases; press 7669 (S-O-N-Y) when the disc’s main menu appears.

If it’s the performance of a built in tuner you’re after, then things are a little trickier, as there aren’t many testcards broadcast – but BBC HD does transmit one, as part of its daytime preview loop, and you can find more details, and instructions on how to use it on the BBC Internet blog – it’s well worth reading that post; and again, if you have a media player that you want to calibrate from a still image, then you can download the testcard from Flickr.

BBC HD testcard

The BBC testcard is broadcast on the HD channel, as part of the preview loop

If you want to try and set things up to display correctly from a Freeview receiver, then you can summon a test card on demand, provided your box has an up to date interactive (MHEG) engine. Tune to channel 105 (BBC red button) and wait for the logos and images to appear, then press the Yellow key on the remote. Tune to a different channel, then go back to 105, and this time press Green. When the status page appears, press Green again to display the testcard – though on one of my Freeview receivers, all that was displayed was the centre section, rather than the whole card. Note that the compression on this test card means that it’s not as accurate as one from a DVD or other source, but it should at least point you in the right direction.

If you’re lucky enough to have a FreeviewHD receiver, whether standalone or built into your TV, you can of course use the test patterns broadcast on the BBC HD channel, which will make sure you’re getting the best possible pictures when you tune in.

Adjusting the display

Black level test screen

The brightness control is responsible for the black levels in the picture

Whatever test patterns you have, the first, most basic adjustments, are the same. Turn off noise reduction, and turn the sharpness control of your TV right down. Make sure you turn off any automatic adjustments that compensate for things like changing light in the room, and set the picture mode to ‘normal’ if there’s a choice of settings.

Stage one of lining up your set is adjusting the black levels, which is what the brightness control is for. On the BBC testcard, just to the left of the centre circle, is a set of grey boxes; the top white one contains two dots, and so does the bottom black one. Turn the brightness up so that you can see both the dots in the bottom box; if you’re using a different test pattern, there will usually be a series of black boxes, the darkest of which has the same purpose as the darkest dot on the BBC pattern – it’s ‘below black.’

Slowly turn down the brightness, until the ‘below black’ bar or dot is not visible, but you can make out the next one up. So, on the BBC test card, you’ll be able to see the left dot in the box; if you’re using the first test pattern on the AVS Forums disc image, then you should adjust the settings so that bars from 17 upwards are visibly flashing.

White level test card

This screen shows both black levels and maximum white

The contrast control determines the white levels of the display; with the BBC testcard, you need to adjust the settings so that you can still see the left hand dot in the top box, and the levels don’t blend into each other – though note the information regarding the accuracy on the BBC blog about this setting; with the AVS test signals, you need to adjust the contrast so that bars 230 to 234 are flashing.

A grey ‘ramps’ test pattern – white to black on the top, and black to white below – is a good way of setting the contrast too. Make sure that you can see all the gradations between the different boxes.

You may also need to turn the contrast down a little if there’s a colour cast at high levels, until that disappears – fixing it completely is something that usually requires access to the service menus of the set, and a colorimeter, with associated software tools.

Greyscale ramp test card

The markers show ‘below black’ and ‘above white’ points; if there’s a colour cast, ease back on the contrast

Colour and sharpness

If you want a simple straightforward adjustment of colour, then that’s what the girl in the BBC testcard is for; make her skin tones look natural, and you’re almost there. It’s not the most scientific way, though.

Most test pattern sets will include a set of colour bars, designed to be used with a blue filter, like the ones shown in the screenshot just below. The blue used is typically ‘Tokyo Blue’, or code 071 for lighting gels; a swatch book of filters, or a set of small sheets costs around £10, so it’s probably just as cheap to buy a test DVD that comes with a filter.

Look through the blue filter paying particular attention to the sections with the blue and white patches. The filter strips out the other primary colours, and the colour is set correctly when it appears that the blue and the white patches on the screen have the same brightness – though you may need to tweak to personal taste.

Colour bars test screen

Colour bars are used with a blue filter to set the colour correctly

After colour, turn your attention to sharpness; on the BBC testcard, the gratings to the right are used to check this; other discs have specific patterns. Turn down the sharpness to avoid the blurring round the edges of fine lines, such as those in the gratings, and the worst of the moiré effects (where the straight lines seem to turn into curving patterns) in large shaded areas. But keep an eye on the edge of solid blacks, to make sure they’re still well defined – turn sharpness down too much, and they’ll become fuzzy.

Some of the tests for this – such as the one on Sony BluRay discs – also include markers for overscan; you can use this if your TV has settings to control the picture size, or a simple on/off for overscan, to check that everything is being displayed and no bits of the picture are being cut off.

If you’re using a standard flat planel, that’s more or less it for DIY setup. A colorimeter like the SpyderTV can help you achieve more accurate colour setup – but at around £100, plus your time, if you only have one set to adjust, it may be better value to invest in a professional ISF calibration, if you feel that a visual setup isn’t good enough.

For more advice on that, I recommend the UK-based AV Forums site, which has a specific discussion area dedicated to calibration, and also plenty of people who will be able to help you with specific settings for your particular TV set. There are also some useful video tutorials covering calibration on AV Forums.

 
 
 

Why can’t I have the channels I want?

With the two main free TV services, Freeview and Freesat, providing different collections of channels, including some major notable omissions, like the lack of Channel4 in HD or Dave on Freesat, people often ask “Why can’t I have ‘x’? Surely if they got rid of all the shopping, there’d be space for the things I want.” You’ll see frustrated posts in forums saying “Why can’t Freesat get XX” or “Will YY ever come to Freeview.”

You don’t have to spend long on internet forums where digital TV is discussed to come across topics like this, but the questions are often based on a misconception about how Freeview and Freesat work, so I thought it might be a good idea to explain how this works.

Freeview and Freesat are pretty similar in some regards. They provide an easy way to make free television available, through your aerial or a satellite dish. And a lot of what they do is about marketing – telling people “Buy a Freeview/Freesat box, and you get these channels free.” They also set technical standards that ensure all the boxes with the logo on them will work properly; Freesat also looks after the ‘Electronic Programme Guide’ or EPG, which means deciding which channel goes on which number. That’s pretty much it, for both organisations.

In the picture

What neither of them does is broadcast TV channels. That might seem strange, but it’s key to the question of which channels appear in the guide on which boxes. For a TV channel to appear, it needs ‘carriage’, which means an arrangement with the people who run the transmitters for terrestrial TV (Freeview), or the satellites for Freesat. We’ll leave cable out of it for now; the key thing is that Freeview doesn’t own the transmitters, and Freesat doesn’t own the satellites.

For terrestrial TV, the transmitter network is owned by a couple of companies, and if you want to run a TV channel, they’ll let you know when there’s space to add one, and you can bid for it; usually, the highest bidder wins – sometimes the transmitter company might use other criteria – and then the channel broadcasts, and it appears on Freeview.

For satellite TV, a channel goes to the satellite company (or to someone who’s already bought lots of space on the satellite), and pays for some of it. The channel goes on air, but at this stage, it doesn’t appear on the satellite EPG. For that to happen, the channel has to pay another fee, either to Sky or to Freesat, or to both. When that’s done, the channel appears in the programme guide, at the number allocated by Freesat or Sky.

Taking up space

So, as you can see, there’s more than just Freesat or Freeview involved in this – and in the case of satellite, a channel could be on just Freesat, or just Sky, if they wanted. And since neither Freesat nor Freeview (or indeed Sky) owns the transmission systems, they can’t ‘bring’ a channel to their service – the channel has to want to go there.

Now, that complaint that  “shopping channels, or +1 channels take up space. Can’t we have something else?” It’s a nice sentiment perhaps (unless you like the shopping channels, or the +1 channels), but as I’ve explained, the carriage isn’t down to those Freesat or Freeview. The contracts to actually broadcast the channels are with other people, and as long as they’re being paid, they aren’t going to say to someone “Look, sorry, we know home shopping is what you do, but just go away and we’ll sell the space you’re using to someone else.”

Neither Freeview nor Freesat has the power or contractual right to say to the people providing the carriage “Turn that channel off, and give its space to someone else.” It would be a bit like London Transport saying to one of the bus companies that run services for it “We print the timetables, so we’re going to say you can take sportsmen, but not shoppers on your buses.” As long as everyone pays their fare, London Transport simply can’t do that.

A quick point with regard to Freesat. We mentioned earlier that a channel can be on the Freesat EPG or on the Sky one, or on neither. Even if a channel were taken off the Freesat guide, that doesn’t mean it would ‘free up space’ for someone else. All that would be freed up would be the number – the channel could still be there, using capacity on the satellite, without being on any programme guide.

Bring me my favourites

Lastly, there are important rules about programme guides, to ensure that they’re operated fairly. For example, these say that the original terrestrial channels should appear first. And charges have to be non-discriminatory, too. That means that a special deal can’t be done to entice a channel onto a service. This doesn’t make much difference to Freeview, with its limited space. But it does tie the hands of Freesat. There might be a great channel, that’s on satellite, but not on Freesat. No matter how great, Freesat’s simply not allowed to say “Come on our EPG, so our viewers can tune in – we’ll give you a special discount.”

So, as you see, both Freeview and Freesat have their hands tied to an extent. It’s simply not within their power to turf one channel off, in favour of another; they don’t run the transmitters or satellites. Even if they did, they would have to be non-discriminatory.

There’s one other issue affecting which channels you can get on Freesat, which is copyright and coverage. But that’s a topic for another post.

 
 
 

Are you ready for HD?

According to a recent survey by the British Video Association, there are a lot of people out there who aren’t entirely clear about HD – what is it, what they need to watch it, and so on.

Rather than say “Gosh, aren’t people daft,” let’s look at the answers to those questions. First, to understand what High Definition (HD) is, you probably ought to know what it isn’t.

Standard Definition, or SD, is what you’ve been watching for years. And with digital TV in the UK, it means a picture made up of at most 576 dots or pixels (one per line) from top to bottom, and 720 left to right. The picture is drawn first with the odd lines, and then with the even lines, a technique called ‘interlace.’ I say “at most” because some channels use fewer pixels.

A picture is often described using a shorthand giving the number of lines, and a letter; standard definition is referred to as 576i, where the ‘I’ means ‘interlace.’ This is the sort of picture that almost everyone in the UK is watching at the moment.

High definition

High definition pictures that are broadcast in the UK on Freeview HD, Freesat, and Sky HD are usually 1080 dots from top to bottom, and 1920 left to right, again drawn first with the odd lines, and then the even lines; this is often referred to as 1080i.

A quick bit of maths reveals that that means there are five times as many dots in an HD picture as in an SD one, hence the ‘five times clearer’ boasts of HD. The other thing about HD in the UK, is that it’s often broadcast with high quality surround sound, whereas SD just comes with stereo.

If you have a Blu-Ray player, it can also create pictures in a format referred to as 1080p; the ‘p’ stands for “progressive” which means that instead of drawing first odd and then even lines, the whole picture is displayed in one go. This is about the best quality you’ll get, but it’s not yet practical to broadcast it. A third HD picture size is referred to as 720p – that’s 720 dots top to bottom, and 1280 left to right, displayed in one go. But it’s not used by any UK broadcasters right now, so you don’t need to worry about it too much.

So, with all those extra dots making up the picture, HD can provide a much clearer picture than SD – that’s better detail for football, or more realistic nature documentaries, and scarier aliens.

However, as the BVA survey showed, a lot of people don’t quite know what they need.

Is your TV set ready?

The first thing you need to watch HD is a television that can display an HD picture. Simple enough – just about every TV set you can buy these days is labelled ‘HD Ready.’ But this is where the confusion sets in.

HD Ready means just one thing. It means that the TV has a wide screen, made up of enough dots to show an HD picture, and a connection on the back that can be used to feed the HD picture into it. That’s it.

It does not mean that an ordinary picture watched on the set magically becomes HD; it doesn’t – it’s just magnified to fill the screen. And it doesn’t even mean that the set will pick up the new Freeview HD signals. All it means is that, if you have something that creates an HD picture, the TV can display it.

That ‘something’ might be a SkyHD box, a Blu-ray player, a games console, or a Freesat or FreeviewHD box. Without one of those, all you’re watching is an SD picture, through a magnifying glass – and we all know that look closely enough at something in a magnifier, and you can spot the flaws.

HD Ready logo

This label just means your screen can show HD pictures

TVs usually have a label to show they’re ‘HD Ready’, and some have a label that says ‘HD Ready 1080p’ which means the screen has enough dots to show a 1080p picture, without having to shrink it to fit; without the ‘1080p’ bit, a set has to have at least 720 dots vertically to qualify for the label.

What about Freeview HD?

So you have a TV with built in Freeview, and it’s HD Ready. Doesn’t that mean you’re watching FreeviewHD?

No. FreeviewHD is a brand new system, and until early this year, there weren’t any TVs available that worked with the new technology involved. Some TVs may work with the HD services broadcast elsewhere in Europe, but not with FreeviewHD. These sets – like any other HD Ready set – won’t show the FreeviewHD programs on the guide, and when you watch existing Freeview channels (or Sky channels that aren’t in HD), they’ll still all be in standard definition, just made big enough to fit the screen.

HD TV logo

This label indicates that a TV or receiver can tune into HD channels - but that doesn't necessarily include FreeviewHD

The only way to tune into an HD broadcast is with an HD receiver; there’s a special logo for those, and there’s also a logo specifically for FreeviewHD, which guarantees the set will work with things like the BBC’s interactive pages. Some sets also have Freesat HD built in, so you can watch their HD channels.

But, unless you have a TV that specifically includes FreesatHD or FreeviewHD built in, you will need a separate box to watch HD broadcasts. That might sound a bit frustrating if you’ve recently bought a TV, but over the next few years more and more TVs will include, at least, the capability to receive FreeviewHD as standard.

In the meantime, to watch TV in HD you need either a SkyHD box, a Virgin HD box, a FreesatHD box or a FreeviewHD box. To watch films in HD, you’ll need a Blu-ray player.

If you don’t have one of those, even if your screen is ‘HD Ready’, you’re not watching HD – you’re just watching SD through a magnifying glass.

FreeviewHD logo

The Freeview HD logo means a TV or set top box can tune into FreeviewHD

 
 
 

Satellite basics

Originally published in Personal Computer World as a part of the article All about Freesat

Satellite basics

If you have a satellite dish already and want to add a PC card or Freesat receiver, it’s not quite as straightforward as splitting a terrestrial TV aerial.

For Freeview, you can simply use a splitter – and many PVRs have one internally; just one cable can feed both the tuners in a PVR, though there may be a small loss of signal. Since the TV aerial is just a lump of metal, it doesn’t care what you plug it into, or how many devices there are. But the satellite world is very different.

At the end of your satellite dish arm is the Low Noise Block downconverter, or LNB. This shifts the frequencies of broadcasts and then sends them along the cable to the tuner in the receiver. And unlike a TV aerial, it’s not passive; it has to be set to high or low band, and vertical or horizontal polarization, by the receiver. So two tuners on the same LNB would be forced to watch channels in the same band and polarisation.

For each tuner to have complete choice of available channels, it needs its own LNB and connecting cable. You can buy a dual LNB, which is one unit to mount on the satellite arm, containing two independent outputs, and quad or octo ones too, with 4 or eight. A twin tuner PVR will need two connections – so on many installations, a quad LNB is standard now, to allow for additional receivers.

For more options, a Quattro LNB has four fixed outputs – one for each combination of band and polarisation – and is used with a multiswitch. These work a bit like a TV aerial amplifier, allowing many outputs – 12, 16, or more – and look at the signal from the tuner, then connect that tuner to the appropriate signal from the LNB, allowing full channel choice on every connection. A fifth input on most multiswitches allows them to be used to pipe terrestrial TV around the home too.