Established for around 10 years, DVB-S has been the de facto modulation standard for broadcasting digitally by satellite. Technology has moved on, DVB-S has now been eclipsed by a more efficient variant known as DVB-S2. It should come as no shock to learn that DVB-S-compliant products are incompatible with the new breed of DVB-S2 services.

Currently, these tend to be HD channels using the cutting-edge H.264 video codec rather than the MPEG-2 traditionally associated with DVB-S. They include a handful of free-to-air channels and pay-TV packages on Astra 1 (19.2°E) and Hot Bird (13°E).

Among them are Astra's unencrypted HD 'barker' channel, ProSieben HD, Anixe HD, LuxeTV and the pay-TV service HD1/Euro1080. SkyHD, carried via Astra 2, has also plumped for DVB-S2, and the PVR sold by Sky for its service has a pair of tuners able to receive both DVB-S ('legacy' standard-def Sky Digital) and DVB-S2 (SkyHD) services.

Interestingly, the free-to-air BBC-HD trial channel that SkyHD subscribers enjoy as an added bonus combines DVB-S modulation with H.264 and can thus be received with a PC equipped with a standard tuner card and H.264 software codecs.

Decoding H.264 in real-time at hi-def resolutions (1280 x 720 or 1920 x 1080) is a punishing task for PCs. You'll need a very fast PC - 3.2GHz Pentium 4 or equivalent - equipped with a powerful graphics card.

Although the reception of BBC HD outside the DTT trial area without a need for a Sky subscription may be an excuse to upgrade that PC to a meatier model, the extra channels available elsewhere on the Clarke Belt wouldn't go amiss. In any case there's no guarantee that the Beeb won't switch to DVB-S2 in the near future - assuming that it's allowed to continue.

DVB-S2 tuners for PCs were first hinted at last year, but the Far East-sourced product in question only surfaced in Germany - the first European country to switch to HD satellite in a big way. Funnily enough, German company Technisat is offering the UK its first DVB-S2 card.

The card in question is made for Technisat by Technotrend, and - like the SkyHD and Pace DS810 boxes - is also compatible with standard DVB-S services. In other words, the same card will receive both standard and high-definition channels.

Like other PC tuners, the SkyStar HD is a small PCI card. The screened tuner module, which is built on the board itself, feeds its signals to a ST chip that carries out DVB-S or DVB-S2 demodulation according to the chosen service.

The demodulated transport streams are then passed to the PC via a Philips PCI bridge - from there, software takes over. A large multi-pin header is provided for a forthcoming CI interface (the only DVB-S2 card to support pay-TV services as standard is Twinhan's DTV DVB-S2 CI).

On the backplate is a standard F-connector for your LNB/dish, plus a socket for a trailing IR sensor. This allows the tuner software to be controlled by a software- customisable remote handset of the Technisat house style. We installed the SkyStar HD in a custom-built Windows XP PC based around a 3.2GHz Intel Pentium Extreme Edition with no trouble.

Even the software installation proceeded without a hitch. The software includes BDA (Broadcast Driver Architecture) drivers, a data application, video-editing program and decoders able to handle both MPEG- 2 and H.264.

The main program (Technisat TV Center) is not the DVBViewer that traditionally ships with SkyStar products. TV Center's setup menus, accessed via a button on the main window, configure AV, EPG, appearance, recording and your dish/LNB feed.

As with most satellite tuner cards, only DiSEqC 1.0 is catered for. This need not be a problem for those 'looping' from an existing motorised dish rig; simply disable DiSEqC, and manually switch (from the setup menu) the satellite you're after.

Another main-window button tunes in channels, manually (by satellite/frequency/symbol rate/polarisation/ modulation) or automatically. Tuning in channels is very slow. A full scan of the Astra 19°E cluster took over 10 minutes. And when switching between channels waits of more than a few seconds are not uncommon. Another annoyance - especially if your PC is doing something else - is that the TV Center window is always 'on top'.

The prominent channel list covers the radio and TV services of all satellites, but the ones you access frequently can be defined as favourites.

But finding a channel in the first place is a navigational nightmare. Channels are listed only by provider. There's no alphabetic search, or even the ability to group channels according to satellite. All you can do is hide encrypted channels or specify TV and/or radio.

TV Center supports digital teletext, full-screen viewing, sleep-timer, picture-in-picture, timeshifting (which uses the PC's HDD as a temporary buffer) and both manual and timed recordings of radio or TV channels.

The EPG supports now/next and seven-day schedules - it's augmented by an unusual magazine that allows the EPGs of several channels to be listed side by side. Scheduling recordings from the EPG or magazine views is possible.

Both video and audio (Dolby Digital and MPEG-1 Layer 2 are both supported) come across very well. SD channels look good, but hi-def takes you into another world with its crystal clarity. To get the best from such services, take a DVI or HDMI feed from your PC to a HD-Ready TV. Don't forget to configure your PC's display settings to match the resolution of your display and view the channel full-screen.

In terms of sensitivity most standalone receivers fare better. And engaging timeshifting would occasionally cause TV Center to crash. Thanks to BDA, third-party apps like recent versions of DVBviewer and the freeware DVBDream can be used instead. These programs make far better concessions to channel organisation and are somewhat easier to use.

But overall, the SkyStar HD is the most exciting PC-related satellite product we've seen for ages, and it puts PC-based satellite systems back into the driving seat. Martin Pipe