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HINTS & TIPS 64

 

TV/VCR AND SATELLITE QUERIES

 

STATIC SOLUTION

Name                          Paul Simons, Monaco                                 

Kit                               Sony KV28FD1 TV

Problem                      Following the glowing reviews and EISA award Paul decided to buy a Sony KV28FD TV. After thirty minutes the set makes a 'static' noise when the picture on the screen changes, it's loud enough to be heard over the speakers. The set has been back to the shop twice but on both occasions it was given a clean bill of health, and a replacement TV suffers from the same problem, but he has noticed that TVs in dealer showrooms do not make this noise.

 

Expert Reply             The solution to this problem may lie in the fact that similar TVs in the showroom do not make a noise during a scene changes. Static build up on a picture tube is quite normal; you can often hear the discharge -- a kind of 'shooshing' noise -- when the TV is switched off. A similar discharge can occur when there is a sudden reduction in brightness level but you don't usually hear is as the charge tends to be dissipated slowly, though you may become aware of it in very dry weather. It is possible that the atmosphere in Simon's house is very dry, especially if his home or apartment has warm air central heating and is well insulated. That could explain why it didn't happen in the showroom. If that is the case he might like to try an experiment with a room humidifier and see if that makes a difference.

 

TIME TO SWITCH

Name Simon Hewer, Streatham

Kit                   Sanyo VHR-4350 VCR, Mitsubishi TV

Problem            Simon's VCR has started misbehaving, every so often it refuses to lace up the tape -- after loading it spits it out a couple of second later -- once or twice it has refused to eject, unless the machine is first switched off, then on again. It's an oldish model, so is it worth repairing, Simon wants to know?

 

Expert reply            This sounds suspiciously like a fault on the system control ('Syscon') switch. This is a small mechanical device that controls the various tape deck functions, ensuring that things happen in the right sequence. Even if the part was still available -- which we doubt -- quite honestly the cost of repairing it, plus labour charges, is going to be more than this very old machine is worth. It's also likely that other components will either fail or need replacing, so Simon really should be thinking about buying a new machine.

 

TOSH HISS

Name              J.T.Crossley, Wakefield

Kit                   Toshiba 2877DB and 2987DB DPL TVs    

Problem            Mr Crossley is unhappy with his three month old Toshiba 2877DB TV. He has become aware of a constant 'hissing' sound coming from the rear surround speakers in Pro Logic and simulated surround modes. Visiting engineers have told him that some background hiss is normal. Subsequently he complained to the dealer and the set was exchanged for the 2987DB but he says the hissing noise was even worse. He has been to three other retailers in the city and listened to a number of Toshiba demo TVs and all of them hissed. He has tried other speakers on his own TV, with no change in the noise level, can we help? 

 

Expert Reply Dolby Pro Logic is an analogue system and inherently noisy, our experiences with Toshiba DPL TVs has shown them to be no worse than most others makes in that respect. Background hiss levels are naturally quite high, especially on centre-front and rear channels. Normally it is masked by the soundtrack, the fact that the speakers are usually some distance from the viewing position and the relative volume levels of the surround channels, compared with the right and left stereo channels. In a smaller room, where the speakers may be positioned quite close to the viewer it is vitally important to get the channel levels right, using the noise sequencer built into the decoder. Without knowing the location of Mr Crossley's speakers it is difficult to say whether that is the cause. However, the fact that he has problems with two separate TVs suggests that it might be down to alignment, and it is compounded by he fact that he has become more aware of the noise, and is now listening out for it.

 

WIDER ISSUES

Name  Geoff Farmer, via E-mail

Kit                   Grundig M82-169 TV, JVC AV system, Panasonic DVD

Problem            Why won't Geoff's TV switch to 16:9 mode when he is watching a wide screen movie? He says this function is mentioned in the instruction manual. The player is connected to the TV by audio and S-Video leads.

 

Expert Reply

Automatic widescreen switching can only happen when the DVD player and TV are connected together by a fully wired (Type U or Universal) SCART to SCART cable.  The S-Video lead only carries video signals.

 

DIGITAL PLOT

Name John Andrews, Stockport, Cheshire

Kit                   Akai STV receiver, Sony KVS3432 TV

Problem            When John first brought his Sky satellite system five years ago he was very pleased with the picture and sound quality but within the last six months he has noticed a steady increase in noise and grain in the picture, yet the sound is okay. He wonders asks if it has anything to do with the fact that SKY has started digital broadcasting?

 

Expert Reply            As conspiracy theories go that's quite a good one, though we have it on very good authority that the technical quality of SKY analogue signals, and all of the other channels broadcast from the Astra satellites has not deteriorated since the start of digital broadcasting. A far more likely explanation is a nest of spiders in the dust cover on the LNB on John's dish, or moisture has seeped into the cable or connections. Dishes can also go out of alignment -- did the picture get worse following the recent storms? The system needs to be thoroughly checked out and since that will probably involve shinning up a ladder, it's a job best left to an engineer. One last thought, if it looks as though it could turn into an expensive job, it might actually be better to make the jump to digital...

 

WIDE WINDFALL

Name  Sylvia Kemp, Tunbridge Wells, Kent

Kit                   21-inch Goldstar TV, Aiwa DPL mini hi-fi system

Problem            Having come into a small inheritance -- she doesn't say how small -- Sylvia is quite keen to replace her old TV with something a little more up to date. She says her Goldstar set is on the small side, and she quite likes the idea of going widescreen, but what features should she look out for, bearing in mind that she already has DPL on her hi-fi system. She also asks when will the price of plasma TVs come down?

 

Expert Reply            TVs have a typical life expectancy of around eight years so Sylvia should think very seriously about buying a widescreen model now as a growing proportion of what she will be watching over the next eight years will be shown in widescreen format. The general rule of thumb, as far as screen size is concerned, is get the biggest set you can afford, and comfortably accommodate, but in any case avoid 16:9 TVs with screens smaller than 28-inches. Video features worth shortlisting include 100Hz displays, multiple widescreen display options, picture-in-picture -- especially when combined with twin tuners -- and advanced noise reduction systems. Plasma screens will come down in price -- they have already to some extent -- but it will take a few years before they're competitive with CRT picture tubes, so unless Sylvia's inheritance is fairly substantial, she will probably have to wait until her new TV conks out…

 

RECORDING DIGITAL

Name                          Glyn Balmer, via e-mail                

Kit                               digital satellite receiver

Problem                      Glyn read the letter from Chris Frost in the December issue of HE concerning the problem of recording one digital channel, whilst recording another. He suggests that since current VCRs are analogue recording devices, the solution should be simple, connect the aerial output from the digital decoder to the VCR, and then on to the TV?

 

Expert Reply             The actual question was how to record one digital TV channel, whilst watching another digital channel? As we said this cannot be done as you would need two digital tuners, in the same way that you cannot record and watch two analogue satellite channels at the same time. The other problem with Glyn's suggestion is that whilst some digital receivers will have an aerial bypass socket -- like a VCR -- the digital channel will not necessarily be re-broadcast on a UHF channel, so that it can be picked up by the VCR or TV's tuner. Manufacturers and broadcasters want to encourage the use of direct AV connections, which, apart from giving better picture quality, also ensure the TV gets a stereo audio input. Incidentally, D-VHS video recorders may one day be able to record several channels at once, by taping a complete multiplex bitstream, so it might be possible to watch and record different channels, but not yet…  

 

SHARPER SIDES

Name                          Sham Sangha, via e-mail                

Kit                               Panasonic W36D3DP widescreen TV, Panasonic NV-D660 VCR

Problem                      The picture at the sides of the screen is not as sharp as the middle; Sham wants to know if this can be adjusted?

 

Expert Reply             Unless the picture is obviously out of focus what Sham is seeing is almost certainly a by-product of the digital processing that is used to stretch a 4:3 image to fill the 16:9 widescreen display. There are two ways of doing it. The picture can be electronically enlarged to full screen width, in which case the top and bottom of the picture will be cropped, or -- as is the case with this set -- the outer thirds of the image are stretched slightly, leaving the central portion intact. This produces a certain amount of distortion at the sides but since most of the action, and consequently the viewer's attention, is concentrated in the middle of the picture, the effect is tolerable. If the image is actually out of focus then it requires adjustment, however this can only be carried out by an engineer.

 

BOX COPY 1

GETTING STARTED -- THE MILENNIUM BUG

The countdown has begun and if you've been taking the tabloids you are probably convinced that every electrical appliance in your home, from the toaster to the trouser press will be committing hara-kiri on the stroke of Midnight December 31st 1999. Rarely has so much cobblers been spouted, so let's look at the facts, and in particular how the so-called Millennium Bug or 'Y2K' problem will affect your AV equipment.

 

You know the story; to save precious memory space, programming code in computers and microchips used just the last two digits of the year. When the year 2000 comes around gizmos with the Y2K bug will think it’s the year 1900, which means they can't exist, so they keel over and die.

 

Now think about it, how many devices in your home actually know what today's date is, let alone when the year 2000 is going to happen? Did you have to program your vacuum cleaner or microwave oven with date information when it was plugged in for the first time? No, in fact the only date-sensitive products you're likely to own -- that could possibly be affected by the bug -- are one or two extremely ancient VCRs that might make a mistake when asked to make a time-shift recording over the 2000 New Year holiday period. Y2K also affects some older PCs and software but there's plenty of advice and fixes around for that, so we'll stick to home entertainment equipment.

 

Televisions, satellite receivers, AV amplifiers, CD Players, Hi-Fis and even camcorders loudspeakers don't give a monkey's about the date (rumours that they're programmed to go wrong as soon as the guarantee runs out might be true though! Only joking…). But what about those VCRs? Akai say a couple of models made in the late 1980s might have trouble recognising the year 2000, but if you're worried try a Y2K rollover test. Change the time and date to a few minutes before midnight December 31st 1999, program a recording to start a few minutes after the year change, sit back and see what happens. If it fails please write in with make and model number and we'll compile a list, we suspect it will be a very short one...

 

If you are unlucky enough to own such a machine, and you have a burning desire to do some New Year time-shifting the trick is to change the year on your VCR to 1971 in late December as 1972 has the same day/date structure as the year 2000… 

 

LD AND DVD QUERIES

 

MACRO AGGRO

Name                          Colin Marris, via e-mail                

Kit                               Panasonic TX-W282DP TV, Sony DVP-S715 DVD player

Problem                      Colin has been suffering from the same problem as Rob Millington, in the December issue of HE, where the top of the picture bends inwards when playing Region 1 DVDs on his 'chipped' Sony DVP-S715 player. He has consulted with his equipment supplier and Panasonic and they agree with us, that it is almost certainly due to the Macrovision anti-copy process, but the dealer also suggested that the effect might be caused by the TV and have offered to take his TV and DVD player into the workshop, to check it out. Colin is a bit reluctant to let them take his gear away and wonders if we have had any more feedback on this subject.

 

Expert Reply              It is of course possible that the TV could be exacerbating the effect of Macrovision protection but if that is the case it's unlikely anything could be done about it, at least not without doing something fairly drastic to the TV. The simple way to find out is to try another TV with the DVD player. Thus far we haven’t received any other correspondence on this matter but we will be keeping the file open and we'll make it our business try test this combination of products at the next available opportunity.  

 

DUAL DILEMMA

Name              Julian Alcantra, via e-mail                                     

Kit                   upgrading from LD to DVD          

Problem            Julian's Pioneer CLD-1750 is getting on a bit and it has given years of trouble-free service. He originally brought this model for its ability to replay NTSC discs. He wants to get into DVD now that good quality movies, with the kind of extras that were only available on laserdisc, are starting to appear. However, he is uncertain about whether to buy a dedicated DVD player with NTSC compatibility and keep his CLD-1750, or pay a little more for the pioneer DVD-909 LD/DVD player?           

 

Expert Reply             Reading between the lines we suspect that Julian actually wants to be able to play Region 1 DVDs. Most Region 2 players (i.e. those sold in the UK) can replay NTSC discs, but only if they're not regionally coded. All region versions of the DVD-909 are readily available and it's certainly appears to be a very convenient one-box solution but when we reviewed it last summer we felt a few too many compromises had been made. Operation was slow and clunky, DVD picture performance was okay and sound quality only rated as 'average'. We felt it might make sense for anyone with a large LD collection and a second rate LD player, wanting to get a taste of DVD. However, if performance and convenience are important it's better to go for a dedicated DVD machine -- an all-region model if that's want he wants -- with top-notch AV and a few more facilities. Julian can then put his CLD-1750 into well-earned semi-retirement and spend the money he saves on a few more DVDs

 

STANDARD REPLY…

Name              Shaun Philips, via e-mail                            

Kit                   Panasonic TX-21T1  

Problem            Shaun is looking for clarification on a few points concerning DVD and television standards. He says that he understands we use the PAL I system in the UK but he has read somewhere there is a PAL 60 system, what is that? He is also aware that the Americans use the NTSC system and DVDs sold there are designated Region 1. He wants to know if he were to buy a Region 2 DVD player, modified to play Region 1 discs, will he also need an NTSC TV and is it true the picture will have a reddish tint? Finally, will his TV, which the manual says is a PAL I model, be able to connect to a modified Region 2 deck, playing Region 1 discs?

 

Expert Reply  We just about follow that… Let's try and clear up the confusion. When you see 'NTSC replay' on a VCR or DVD player what happens is this. The DVD or VCR in question replays the tape or disc more or less as is, retaining the basic line and frame structure of the original recording. So what comes out of the deck or player's video output socket is a 525-line picture with a 60Hz frame rate -- the same as a raw NTSC video signal. This isn't a problem for most TVs as the video processing circuitry used in most modern tellies can adapt to quite wide variations in line and frame rate. This is due to the fact that TV manufacturers rationalise production by using the same chips and modules in sets destined for different international markets. However, there is a significant difference in the way colour information is encoded in PAL and NTSC signals, so the VCR or DVD player has to do a bit of pre-processing to the NTSC signal, in order for the TV to make sense of it and display a colour picture. This conversion process is referred to as 'PAL 60' by some manufacturers, just to confuse matters others call it NTSC 4.43 (4.43 is short for 4.43361875 MHz which is the frequency of the PAL colour sub carrier, since you ask…). Some TVs can display a raw NTSC signal via the AV input, this is known as NTSC 3.58.

 

The PAL 60/NTSC 4.43 process is not perfect and some combinations of equipment may indeed produce a picture with a reddish tint, but it is by no means common.

 

Most DVD players can do the 'NTSC replay' trick, i.e. output a PAL 60/NTSC 4.43 signal when playing a NTSC disc, the issue of Regional Coding is quite separate and concerns the way data from the disc is processed. According to our archives Shaun's TV is a 90/91 vintage set and the spec sheet shows no indication of any NTSC capabilities, so perhaps he should think about getting a new TV before venturing into DVD.

 

SOLDERING ON

Name                          Mike Fuller, via fax

Kit                               Pioneer Elite DVD player, Philips TV

Problem                      A small item in our recent DVD group Test (December HE) caught Mike's eye. Basically it said that for the best picture quality a DVD player should be connected to a TV using an RGB 'component' connection via SCART lead (where possible) or use an S-Video lead (again, when the TV has such a facility). Mike has a Pioneer DVD player with Y'Cr'Cb' component video output and has tried to get a suitable lead, so he can connect it to his Philips TV. However he has been told that it isn't possible; it sounds as though Mike could be handy with a soldering iron as he's wondering if he could wire something up himself and would like to know which pins on the SCART lead carry component video signals?

 

Expert Reply             There is some confusion surrounding the use of the term component video. Basically it refers to the way analogue video signals are handled or moved around inside a device or system. The simplest type of video signal is called 'composite' video, where luminance (brightness or 'Y') information is mixed in with colour (chrominance or 'C') information, and synchronisation pulses, so they can all travel together down a single wire. Unfortunately the colour and brightness bits of the signal can interact with one another, causing various picture defects like cross-colour or 'herringbone' patterning. There are several ways around that, most involving splitting the video signal up into various components. In an S-Video signal the luminance or 'Y' part and chrominance or 'C' components are seperated (that's what the 'S' in S-Video stands for) and travels down separate wires. S-Video is also sometimes called Y/C. Alternatively a colour picture can be split into its red, green and blue components, and sent separately down three wires. That's how we do it in Europe -- composite, S-Video/YC or RGB.

 

Over in the US they do things slight differently and some players -- including Mike's -- has what is known as analogue colour difference outputs, (usually this is instead of RGB). Colour difference outputs are normally referred to as YUV signals but you may also see them labelled Y'Pb'Pr and sometimes Y'Cb'Cr' (purists argue Y'Cb'Cr' is correct when referring to digital equipment but we'll stick with YUV…). The bottom line is that YUV and RGB are not compatible, so there are no connection leads, so Mike can put his soldering iron away.     

 

WHAT A GREY DAY

Name                          Mingus Cornish, via fax                  

Kit                               Pioneer CLD-D515 LD player, Sony KV28WF1 TV, Panasonic A100 DVD player

Problem                      When playing back NTSC laserdiscs on his Pioneer deck Mingus says the image has low contrast and looks 'grey', he has to turn down the brightness to compensate. The LD player and cables have all been checked out, moreover PAL LDs look fine, as do PAL and NTSC DVDs. He asks if playback of NTSC discs, using a raw video feed to the TV, could be causing this problem?  

 

Expert Reply             Inevitably there are small differences in the video levels from various AV devices though normally they are not enough to require readjustment. Assuming the NTSC output level is correct there's no obvious reason why this should happen on your particular set-up, especially as PAL performance appears normal. The only other possibility could be copy protection signals on the NTSC discs, which are designed to confuse the automatic gain circuits in VCRs but can also affect some TVs.

 

BOX COPY 1

GETTING STARTED

 

BOX COPY 2 -- DAMAGING DVD

When CD was first launched back in the early 1980s the shiny discs were touted as being virtually indestructible, remember the famous drill demo? Well as we now know scratches damage CDs, so how robust are DVDs, which have an even higher data density than CD? In theory a scratch can cause even more harm as proportionately more data will be corrupted, at least that's what you would expect. The truth is a bit more encouraging. Since CD was launched all those years ago digital error correction systems have improved in leaps and bounds. In comparison with CD, DVD error correction is roughly ten times as effective so overall it easily compensates for the increased amount of data on the disc.

 

In practice a scratch will cause a significant loss of data but DVD has several of things going for it. Data on a DVD is quite heavily compressed and a lot of information that we cannot perceive has already been removed and will not be missed when the data is uncompressed. The MPEG system is also very good masking picture faults. Our eyes are far more forgiving than our ears when it comes to errors and brief picture artefacts -- blocky colours etc -- are much less irritating than audible clicks or jumps. Deep scratches can render discs unplayable, but like CDs, there are various products on the market that can repair all but the most serious damage, even so it's still a good idea to take all the usual handling precautions and keep discs in their protective cases when not in use.

 

---end---

Ó R. Maybury 1998 0312

 

 

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