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REVIEW: Thomson DTI352TH Digital Set Top Box Digital TV in Australia: the picture so far! Digital TV broadcasts began in Australia in January this year in a less than auspicious beginning. Now set top converters from Thomson are available in the stores and are beginning to trickle out to customers. We decided to take a look at how it’s going. By LEO SIMPSON As a first step, we obtained a Thomson DTI352TH Digital Set Top Box which is currently stocked in the Dick Smith Electronics PowerHouse stores. This prosaically named box is similarly unassuming in appearance, considering that it houses state-of-theart technology. It has a charcoal finish and measures 368mm wide, 70mm high and 225mm deep. Inside, it has a large double-sided PC board with lots of inscrutable LSI and surface mount chips. On the front panel, there is dark window for the remote control and a few buttons which let you access most of the functions via menus shown on the TV or video monitor’s screen. On the rear panel, there are input and output sockets for the antenna, two RCA sockets for the left and right audio outputs and two SCART sockets to allow connection to a VCR and TV/monitor. The accessories include a SCART to SCART cable and two SCART to three RCA sockets for the VCR and TV connections. In my situation, connection was easy since I have a Philips stereo TV with a SCART socket and I used one of SCART adaptor cables to connect the VCR. Also on the rear panel is a 2-pin 240VAC mains socket (the box is double-insulated) and an RS-232 socket. The RS232 socket does not get a mention in the instruction manual and so we assume it is used by the manufacturer to set up the parameters for different countries. The 20-page manual is quite brief The Thomson DTI352TH Digital Set Top Box comes complete with an IR remote control and all connecting cables. The setup is easy, although it does take some time to initially scan in all the stations. 14  Silicon Chip These two pictures dramatically demonstrate the improvement in the author’s SBS reception via the Thomson Set Top Box. The SBS off-air analog signal shown at left is noisy, with no colour, while the digital signal has full colour and is as clean as a whistle. A set top box is very effective when it comes to cleaning up off-air signals in difficult reception areas. but an Australian produced single-page instruction sheet contains enough info to get you started. Basically you connect all the cables, turn it on and press the remote control buttons to bring up a number of menus and then you click down them as instructed. Once you have gone through the initial setup the on-screen menus are more-or-less self-explanatory. Setting up The setup procedure does take quite a long time although you can read a book or have a cup of coffee (or both) while the machine goes through the full VHF & UHF tuning range (from 45MHz to 820MHz) and verifying the existence of digital services. The process seems to take forever but is around 30 minutes or so. In my case, the Thomson box announced that 19 services had been found and installed: one from the Seven Network, four from the Nine Network, six from the Ten Network, three from ABC TV and five from SBS. Bewdy mate! All these extra channels to watch! From then on you can decide whether you want to watch the TV broadcasts in wide-screen (16:9), letter-box or 4:3 Pan & Scan. My TV is a not a wide-screen model so that rules out the first option and I am not keen on letter-box mode either so I did most of my watching in 4:3 pan and scan. Can you pan & scan? I couldn’t so that feature may not yet be enabled. The remote control is quite good and it allows you to control the volume as well as channel selection. Other buttons allow you to bring up various on-screen menus which, among other things, allow you to display channel and program lists (if available for that particular channel) and even to lock out individual channels (eg, if you don’t want the kids to watch something). Reception quality I had a particular interest in reviewing this set top box because my TV reception is quite variable, depending on which set of broadcast transmitters I use. In my exposed position high above one of Sydney’s’ northern beaches I can receive signals from the main broadcast antennas clustered around Gore Hill or I have a choice of UHF translators at North Head or in Bouddi National Park. However, I particularly wanted to check the TV reception from the main broadcast towers in Sydney. Those signals are received by a combination VHF/UHF yagi antenna but we do not have line-of-sight reception. Consequently, while the VHF signals are quite strong they are subject to varying degrees of ghosting, particularly on ABC channel 2. Moreover, channel 2 is subject to varying amounts of local interference, some mains-borne due to motors and power tools and some due to unidentified RF sources. Much worse is the UHF reception from SBS, which is weaker since the beginning of DTV. In fact, with the antenna signal fed direct to my TV, This view shows the on-screen menu that comes up when you go to another channel. This information typically includes the name of the current program and by pressing the right arrow on the remote, you can also find out what’s on next. The yellow button brings up a list for that channel. April 2001  15 REVIEW: Thomson DTI352TH Digital Set Top Box A digital set top box is very effective when it comes to eliminating ghosts, as these two shots from Ch10 demonstrate. The picture at left is the analog off-air signal, which shows obvious ghosting and some noise due to RF interference. By contrast, the digital signal at right is ghost and noise-free. the reception is so noisy that there is no colour. Feeding it via the VCR and then into the TV improves it to the point where colour is present but it is still noisy. So I thought that these signals would be a good test. And they were. In any case, while digital broadcasts are planned from most, if not all, UHF translators, they have yet to be announced, let alone start. So the main VHF broadcasts plus SBS it had to be. Exorcising ghosts In fact, all the Sydney channels including SBS were received completely noise-free and ghost-free via the Thom­son set-top box; clean as a whistle. So effective is DTV in this respect that it must be regarded as a very good cost-effective option for those whose reception is weak or plagued with ghosts. The set top box is likely to be cheaper and much more effective than a major antenna installation and you get the other benefits of DTV as they are introduced. The accompanying photos show the dramatic improvement on SBS – it was very noisy on the analog signal and clean as a whistle on the digital. Of course, Pay TV would be another option for those who have ghost-ridden or weak reception. However my experience shows that the free-to-air stations are OK via Pay TV (Optus or Foxtel) but still not first class – low level ghosting is often still present! In other respects though, the picture quality was a little disappointing. It is still not quite equivalent to a first-class off-air broadcast or to a good DVD. There is not quite enough definition or contrast – the pictures seemed a Sydney Area Digital Broadcasts Identifier Channel & Middle Frequency   Transmitter Location  Start Date Digital 7     VHF6 – 177.5MHz      Artarmon   1/1/01 Digital 9     VHF8 - 191.625MHz      Willoughby   1/1/01 Digital 10     VHF11 – 219.5MHz      Artarmon   1/1/01 Digital ABC     VHF12 – 226.5MHz      Gore Hill   1/1/01 Digital SBS     UHF34 – 571.5MHz      Gore Hill   1/1/01 This panel shows the transmitter frequencies and locations for the Sydney area. This information can be seen for all areas in Australia by going to the website www.dba. org.au/reception/ This site also gives some program information. More information is available on the ABA site at www.aba.gov.au/what/digital/technical although it does appear that it has not been updated recently. Note that the new digital transmitters are in the VHF band, channels 6, 8, 11 & 12. So what happened about the plan to move all stations into the UHF band? 16  Silicon Chip little washed out to me. The exception was ABC TV where the digital picture was clearly very good – almost to DVD standard. It is also apparent that the compression techniques do lead to some funny picture anomalies whereby the main image sometimes seems to lose definition when there is rapid motion involved and also there are occasionally bits of the picture out of place. Both Channel 10 and SBS had some experimental HDTV broadcast signals on one of their channels and these were shown as out of sequence frames – quite odd to watch as it was accompanied by chopped sound as well. Of course, there is no way of watching HDTV signals at present since there are no HDTV monitors or receivers available. Interestingly, SBS also had two foreign language radio broadcasts. Summing up So far then, there is not a lot to excite as far as digital TV broadcasts are concerned. The Thomson Digital Set Top Box certainly works well and as noted above, if you are in a weak reception area, it may be a very effective alternative to a bigger antenna installation. It also cures ghosting completely. If you want more information and a demonstration of the Thomson Digital Set Top Box, go to any of the Dick Smith Electronics PowerHouse stores. They SC can supply the unit at $698.00.