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Name                          Ajay Kumar, via E-mail

Kit                               Sony widescreen TV, Pioneer VSA-E06 THX amp, Pioneer CLD-925 LD player, Kef Reference Series THX speaker system

Problem                      Ajay uses his Pioneer amplifier to control all of the source components in his home cinema system, including the video inputs. He has recently brought a new PC and would now like to incorporate that into his system. He realises the video output from the PC is incompatible with his home cinema system but he has come across a PC to video converter card, however, this only has an S-Video output. He points out that the maximum resolution of an S-Video formatted signal is 600 lines, whereas a RGB resolution can go up to 1000 lines. He would like to know if there's such a thing a processor or switchbox that can handle RGB signals, and whether or not DVD players will have an RGB output?


Expert Reply              You shouldn’t get carried away with the numbers, they're practically meaningless when your video display -- the TV -- is incapable of resolving more than 500-lines, say (it is usually less than that on most 'domestic' televisions). Remember also that DVD (and digital TV) are simply ways of conveying or storing a video signal that still has to adhere to the 625-line/50 HZ PAL colour television standard we currently use.


There are fundamental differences in the makeup of TV and PC images and the construction of the display devices. In other words, the output from a PC, shown on a TV screen, is never going to be as sharp or stable as a PC monitor, something to bear in mind if you're thinking about using a PC with a DVD ROM deck, connected to a TV, to watch movies. Some DVD players will have an RGB output but that's not going to make any difference to image resolution either. Under ideal circumstances it might yield a small improvement to colour fidelity, compared with an S-Video connection, but only on TVs that have been carefully designed, to take advantage of an RGB input.



Name                          Roger Hansen, Norway                      

Kit                               unknown

Problem                      Is this a good time to buy a combined TV/VCR asks Roger Hansen? He would prefer a stereo model but hasn't been able to find any; do we know if anyone makes one?


Expert Reply             Until recently almost all most combis were based around 14-inch colour TVs; they are designed for the bedroom, given to the kids or used as AV presenters in shops and exhibitions, but things are changing. Philips have just announced the very first 21-inch stereo combi, (in Europe at least). We understand the 21-PV688 will be available in Norway in late Spring. We can't tell how much it will cost there but Philips assure us it will be comparable with the combined price of a 21-inch TV and stereo VCR.  Philips have also hinted that a larger screen combi (25 inches?.. ) could be in the pipeline, though it wouldn't go on sale until 1999, at the earliest



Name                          Martin Hilary, via E-mail

Kit                               Toshiba VT856

Problem                      When his VCR is switched off Martin gets dark wavy lines across the screen on TV channel 1; they disappear completely when the VCR is on. The VCR is connected to the TV by SCART cable, with the aerial looped through the VCR to the TV. The picture is perfect with a direct aerial feed (i.e. bypassing the VCR) and it makes no difference if there are any other devices connected to the TV or VCR. Martin has tried changing SCART cables and re-tuning the VCR's RF output, but to no avail. He has re-tuned the TV -- using manual and automatic controls -- and even disconnected pin 19 on the SCART connection (on the advice of his dealer), though this made no difference either.


Expert Reply             It sounds a lot like RF interference from a nearby transmitter but without knowing a lot more about where you live, the age and state of your TV aerial and local reception conditions it is difficult to be precise with this kind of problem. The RF modulator in the VCR gives the incoming signal a boost when the VCR is in standby. This could be amplifying a signal on a nearby frequency, possibly it's a harmonic or co-channel interference from a TV transmitter in an adjacent region. If so there's a number of possible cures, from tweaking the aerial to fitting a simple filter in the aerial feed. It's worth finding out if your neighbours are experiencing similar problems TV, if so that would confirm the external interference theory.   




Name                          Chris Burmajster, via E-mail                  

Kit                               gripe about big screen TVs

Problem                      Chris asks if he's the only person who finds large screen TVs -- over 32 inches -- a step backward in terms of quality? He says they show up the line structure and all the other faults of our 30-year-old TV system, and suggests it's even worse in the US. He has a 28-inch set and finds that he has to sit a fair distance away from it to get a decent picture.


Expert Reply             A fair point and a few years ago I would have agreed with you wholeheartedly but manufacturers are constantly developing new ways of improving the picture quality on large screen TVs. Line structure is very effectively masked on many current models. Other techniques, such as 100Hz displays also help overcome deficiencies in the system. There's plenty more to come including line doubling; though it may be a while before this is featured on mid-range TVs. If you've got the room a big screen TVs can add enormously to viewing enjoyment, especially widescreen models, and one day soon all TVs will be made that way. In then end however, if you spend more time looking at the technical quality of the picture, rather than watching movies or programmes, you will be disappointed from time to time, and it's unlikely Chris will be happy with anything that's available for at least the next ten years. Roll on HDTV.



Name                          Jon Hunt, via E-mail                

Kit                               Philips 6332 widescreen TV, Sherwood surround sound amp, Thorn VCR, Pioneer laserdisc player

Problem                      How does Jon go about decoding PALplus signals? Jon has heard that it's available in the UK and it will give him a true widescreen display. He has been trying to find out more about PALplus but keeps coming up against a dead end.


Expert Reply             Don't get me started on PALplus… It was the best widescreen system we never had! Well that's not strictly true, you do get the occasional PALplus movie on Channel 4, they showed The Madness of King George the other week and it was brilliant, better even than laserdisc or DVD! However, I digress. The reason Jon is finding it so difficult to get any information on PALplus is that it has been sidelined in the UK by digital TV. Digital television technology provides an easier upgrade path for widescreen TV, for broadcasters and manufacturers, it has other benefits too but the point is analogue systems are on the way out. Apart from the few hours of programming transmitted by C4 each week no other UK broadcaster is having anything to do with the system (I seem to remember Granada did a few tests once). Philips and Sony still have one or two widescreen TVs in their range with built-in decoders, but the promised add-on decoder for 16:9 TVs never happened, nor is it ever likely to with digital TV about to take off. For the record, PALplus works by transmitting the missing outside edges of a widescreen picture inside the narrow black bars that appear on the top and bottom of the screen, when a PALplus picture is shown on an ordinary 4:3 TV. Picture quality is outstanding, the costs to broadcasters is minimal and it is 100% compatible with existing 4:3 televisions.



Name                          Douglas Allan, Petersburn, Airdrie                                   

Kit                               29-inch JVC 3D Phonic TV, JVC VCR      

Problem                      A recently installed cable TV box is giving Douglas a lot of grief. He is getting an annoying wobbly line running down the right hand side of the screen, but it's not there when he watches off-air TV. An engineer from the local cable company tried to convince Douglas that it was a problem with his TV but he has seen the same kind of interference on a neighbour's television.      


Expert Reply             Indistinct wavy lines are often caused by problems in the TVs power supply and tube drive/scanning circuitry. They're known as 'spooks' in the trade because they can be very difficult to find. However except on very rare occasions they're visible on all channels and usually the auxiliary inputs as well, which is clearly not the case with Douglas's TV. It's the cable company's responsibility, pure and simple, and it's up to them to sort it out. If the engineer persists in blaming his television Douglas should point him in the direction of his neighbour's TV.



Name                          Paul Reid, via E-mail                            

Kit                               Sony KL50W rear projection TV

Problem                      Paul is really happy with his new TV but he is distracted by the noise coming from the cooling fan, which he describes as sounding like a medium size desk fan. He contacted Sony but they told him the level of noise he is experiencing is normal. He finds that hard to swallow on a TV costing £4500, and is concerned that they haven't actually heard how loud it is first hand.


Expert Reply             I agree, it's impossible for Sony to say that a noise is normal, without sending someone around to have a listen to it, however, to be fair to them, your first port of call should always be the dealer or retailer who sold it to you. It's their responsibility to deal with any problems. Cooling fans do make some noise, but on the KL50's I've seen it wouldn't have been audible over a TV or movie soundtrack at normal listening levels. That suggests to me that yours is noisier than usual. However, it might just be worth checking to see that a wall or flat surface isn't reflecting the noise forward. Also, if you get the chance have a listen to a TV in a dealer's showroom. This will strengthen your case if theirs is quieter than yours. 




A lot of the VCR problems we're sent are almost certainly due to infrequent or non-existent maintenance. VCRs do require periodic cleaning and it's something you can easily do for yourself, though there is no substitute for a thorough overhaul by a qualified engineer. There's no hard and fast rules but it's a good idea to use give your machine a regular run-through with a cleaning tape every three or four months, more often if you play a lot of rented tapes. Each time you post a tape into your machine it takes with it hundreds and probably thousands of dust particles. Tapes also shed magnetic particles, and contaminated air is continually drawn in through the ventilation slots by rising currents of warm air. Eventually some of those particles will find their way into the microscopic gaps in the recording/replay heads and when that happens the picture will start to deteriorate. This is a slow process, so you may not notice a sudden drop in quality, but following a cleaning session there is usually a noticeable improvement in sharpness and a reduction in noise. If you haven't cleaned your machine since new a 'wet' type cleaner is normally the most effective; 'dry' cleaners are better for regular use.





Name             Tony Bricknell, via E-mai;                                                

Kit                   unknown       

Problem            Tony tells us he's not one to be satisfied by product reviewers colourful language when it comes to DVD, he want hard facts! His shopping list includes the truth about resolution, how will it handle widescreen films (letterboxed, anamorphically compressed etc.), and what sort of compression routines are used to squeeze all that information onto the disc?


Expert Reply             Last point first. Most movies transferred to DVD will originate from a digital studio master tape. The information is compressed using MPEG2 encoding. This is a 'lossy' system, it discards redundant information -- small colour changes and parts of the picture that don't change etc -- that theoretically won't be noticed by the viewer. Resolution on PAL players is theoretically in excess of 500-lines, which is significantly better than laserdisc and Super VHS (400 lines on a good day), and roughly equivalent to broadcast TV so pictures should look sharp and clean. As far as widescreen movies are concerned, it will depend on the software. Suitably equipped widescreen TVs will automatically expand anamorphically processed films; on letterboxed material you will have to manually select the appropriate zoom mode. 




Name                          Peter Tomkies, via E-mail

Kit                               Considering DVD

Problem                      After reading the reply to a letter in the April/May issue of Home Entertainment, concerning NTSC 'stutter', Peter says he has also noticed it on US TV programs, shown on British television. He says that he finds it amazing that so many people watch only NTSC material on laserdisc, and the effects can only be exacerbated on large screen TVs. Do people just accept it? How bad is it really? 


Expert Reply             Peter is referring to the 'pull-down' process that's used to convert movie film to NTSC video (tapes and disc). This produces a slightly 'jerk' in the picture every so often that's most noticeable during a slow pan. The point to make about pull-down is that it doesn't affect picture quality per-se, it's a type of motion artefact and unless you become aware of it, it's not usually too distracting. Once you do notice it however, it can become quite annoying. However, for movie fans the main reason for buying NTSC discs is the opportunity to get hold of material ahead of it's UK release, and in some cases, to see films that are never released here, or uncut versions. This has been a particular problem with laserdisc, which never achieved the kind of popularity here than it enjoyed in the US. Hopefully that won't be such a big problem with DVD, assuming it takes off, many more movies will become available, more quickly, as the user base grows.



Name                          Simon Tully, via E-mail                

Kit                               Pioneer CLD-2950

Problem                      Can we help with three faults on Simon's Pioneer laserdisc player? The first one concerns moire patterning, moving across the picture, which makes viewing impossible. Fault number two is that sometimes, after pressing the Stop button, the disc stops but it won't allow him to eject it, and it takes ages to switch off, after pressing the standby button. The last one concerns audio CDs, moments after a disc is loaded the disc stops and is ejected.


Expert Reply             It is possible they are all connected. Unfortunately there's little you can do from the outside, though it is definitely worth trying a good quality disc cleaning kit, before you take it for an internal examination. Grime on the pickups can result in erratic behaviour by preventing the machine from reading disc data. There's also a chance this could be responsible for the patterning Simon is seeing. Apart from that there's not a lot else he can do, but he mustn't even think of opening it up, to have a poke around inside. No good will come of it and Simon could be left with an even larger repair bill!




Name                          Paul Seales, via E-mail                

Kit                               Sony DVP7000 DVD player, 29-inch Sony NICAM TV

Problem                      When playing certain discs on his DVD player Paul noticed a faint blue streak across some skin tones. It only happens on a few discs -- Jerry MaGuire is one of those affected  --  it's not a major problem but Paul would like to know if it has anything to do with his Sony TV, which might not be fully NTSC compatible.


Expert Reply             The fact that most of Paul's discs play satisfactorily tends to rule out the TV compatibility theory. I would have expected colour faults to be far more prominent and frequent if that were the case. By the same token any problems with the player should be obvious on most if not all discs. The faults sound quite subtle, which makes me think it might have something to do with the coding on the discs; certainly there were problems with first generation recordings and there have comments regarding the quality of skin tones on PAL DVD pressings of Jerry Maguire. 




Just when you thought the powers that be had sorted out the audio specification for DVD and it was safe to buy a player, another TLA (three letter acronym) rears its troublesome head. This one is DTS which stands for the Digital Theatre System. It's a rival to the 5.1 digital sound systems (five discrete full bandwidth channels, and one bass channel), currently used on DVD and it's threatening to muddy the waters once again. DTS uses less compression than AC-3 or MPEG audio so it promises even higher audio quality. Some US fans reckon it is so good that could eventually become the DVD standard... However, before you start to panic there's no way it will ever replace the AC-3/MPEG soundtracks, they are part of the DVD specification and cannot be omitted on recordings. The problem, however is that no current DVD players have an on-board DTS decoder. Without a suitably configured output, it won't be possible to retrofit DTS decoders since the player won't be able to read the data on the disc. The only small crumb of comfort is that there are no DTS encoded discs at the moment, so you're not missing anything, but in a year or two's time, who knows?   




Ó R. Maybury 1998 0605




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