Key to detailed test reports

Here are explanations for the technical terms in the set top box and digital TV recorder summaries and some additional information.

HDMI, SCART and UHF cable supplied These are the cables for connecting the set top box or digital TV recorder to your TV. If they are not supplied, you can buy them at an electrical accessories shop. All TVs should have a SCART socket for connecting standard definition boxes and modern ones should have HDMI sockets for connecting High Definition boxes. If your TV is very old it may not have a suitable connection so you will need a digital box with a built-in modulator (it will have a Yes in the Modulator Output line under AV connections in the summaries).

UHF Feedthrough. This allows you to connect an aerial cable between the box and the TV which will feed the 5 analogue channels from the aerial to the TV but this is not really needed and will be redundant after digital switchover in your area.

Size We give dimensions. In fact almost all the boxes ranged from the size of a paperback book to that of the average DVD player. The smaller ones could sit on top of a regular TV – though not on a modern flat panel screen, of course – and the larger ones need a shelf to themselves.

Front panel display This is not essential, as most information will be displayed on the TV screen. It can also be useful if you have the digital box connected to your HiFi – because you can have the TV off and still see which radio station you are tuned to.

Remote control for TV functions A useful feature that means one remote control can be used for both the digital box and the TV. You need first to set up the new remote to recognise your particular brand of TV. The user instructions should explain the process. Supplying a universal remote control is likely to raise the price and few boxes come with one.

Radio/TV button Quickly switches the digital box between TV and radio stations. Without this you have to scroll all the way through the TV channel list to get to the radio channels.

STB/TV button This switches between watching digital TV to any other device connected to the TV. Mostly not essential because the TV does the selection automatically, but sometimes it is useful – like when you’re watching a DVD and want to check what’s on TV.

Channel list This is a simple on-screen list of all the stations. You scroll down to select the TV or radio station you want. Simpler than using the on-screen TV guide or the numeric buttons, where you have to remember the channel or station number.

Can delete unwanted channels Useful for removing or hiding TV channels you will never want.

PIP of current channel displayed in on-screen TV guide Picture in picture gives a small picture in one corner of the guide screen showing the currently tuned channel
– so you can carry on watching while browsing what’s on.

UK languages for subtitles On many boxes you can choose a language for subtitles. This will work only when the broadcaster is actually transmitting these languages.

Subtitle smoothness on rapid live subtitles
This new test has recently (June 2009) been added to the programme. It is based on ‘rapid live’ transmissions (as opposed to pre-recorded subtitles). If the product has been tested for this the findings will be noted. See subtitles for more information.

Audio description When available on the programme being broadcast this feature can decode extra spoken descriptions of what is happening on the screen – when these are broadcast. It is intended for people with visual impairment. See audio description [in our existing general report] for how to get it on the different platforms.

AV connections Check here for the types of video signal available from the SCART sockets. There are three alternatives. RGB signal gives the best quality for standard definition connection to a TV. For connecting to a DVD recorder, RGB or S-Video signals are best. The basic level video connection, available in all SCARTs, is usually just called video or sometimes, composite or CVBS. It is the normal signal used for an old style video cassette recorder (VCR). The correct choice of RGB or basic video will be made automatically by the SCART but if you need S-video then this is usually selected via the set-up menus. High definition recorders will have an HDMI output to the HDTV (or HD Ready TV) but will not have an HDMI input for recording from HD devices. The only HD sources they can record from are the internal HD TV tuner or on Blu-Ray recorders an input for an HD camcorder.

Digital Audio output Look for this if you want to connect certain audio systems. In particular, it provides surround sound to home cinema systems, for some programmes.

5-Volt DC option on aerial input This can be used with a few brands of amplified aerial (typically indoor aerials) instead of connection to a separate mains supply. See our indoor aerial test reports for models that can be powered this way.

SCART status signals One of the advantages of using a SCART lead is that it can send special signals to control the TV. We have checked that each digital box can send two important signals. RGB status tells the TV that it should use the better quality RGB signal being sent. The other is to tell the widescreen TVs if the picture should be displayed in widescreen mode or in standard 4:3 mode. Lack of these signals probably means you will need to switch the TV to the correct operating mode.High definition recorders will have an HDMI connection and these also have a similar and potentially more versatile system called CEC (see jargon buster).

Updates Digital TV products are like computers and run using internal software. It is possible to update the software to add new features, correct problems or make improvements. There are three methods of ddoing this: If it is a TV broadcast releted update then it can be broadcast over the air (OTA) so you do not have to do anything. On Freeview this update is only broadcast for a limited time so your digital TV has to be connected and in standby to capture it. To find out if one is scheduled, you would need to visit www.dtg.org.uk/retailer/download_schedule.pl and search for your brand of box.If you missed the update or want to get other non broadcast software updates you can visit the manufacturers web site where you can usually download the latest version onto a USB memory stick and then plug this into your iDTV. The web sites give full instructions. Finally, if you have one of the latest TVs that connects to the Internet, some updates will arrive autoamtiaclly via this route. The cable TV operators Virgin and the satellite TV operator Sky send their updates over the air regularly.

MHEG5 v.1.06 .MHEG is the technical name for the 'teletext' system used by digital terrstrial TV and version 1.06 is the latest version introduced in Autumn 2006. MHEG offers more interactive features that the old teletext system. On BBC channels the service is accessed via the "red button" on the remote control while other broadcasters use the "text" button. Unlike analogue TV, digital TV has some TV chanels that are text-only.

Multiplex changes. A digital TV multiplex is a group of digital TV stations bundled together so that they all fit into one broadcast channel. At digital switchover some multiplexes will change, so digital terrestrial boxes will have to be re-tuned – some automatically and some manually. Check which in the detailed test reports.

DTG Testing. The industry body Digital Television Group carries out testing of digital TV products, including for the Digital Tick. You can be confident that a DTG tested set top box or digital TV recorder will carry on working through digital switchover.