HOME ENTERTAINMENT 98

 BootLog.co.uk

HomeSoftwareArchiveTop TipsGlossaryOther Stuff

HINTS & TIPS

 

QUERY OF THE MONTH

 

NET GAINS

Name              Andy Taylor, Kendal, Cumbria                                 

Kit                   Thinking of buying a new TV          

Problem            Not so much a problem as a case of mild curiosity. Andy is thinking seriously about buying a new large screen TV, possibly a widescreen model, he hasn’t decided yet. He has been looking through a lot of sales literature and keeps coming across TVs with ‘VGA’ and ‘SVGA’ compatible inputs. What’s that all about, he want’s to know?

 

Expert Reply             VGA and SVGA, as you are probably aware stands for Video Graphics Array, and Super Video etc. etc…, they are both display systems used by personal computers. Having this kind of input means you can connect your TV to a computer, but as anyone who knows anything about TVs and PCs will tell you, televisions make very poor monitors, even if they have got the right sockets. The coloured phosphor dots or stripes are much bigger on a TV screen, and the way the picture is made up is different, so televisions are not very good at presenting fine detail, though they’re fine for graphics, pictures and biggish text.

 

However, the real reason manufacturers have gone to so much trouble to fit PC sockets is the impending arrival of set-top internet boxes, a couple are here already. The idea is they connect to the TV, using the PC socket, for the best possible picture. We can expect to see and hear a lot more about Internet connectivity when digital TV arrives. An internet box connects to a satellite dish and a normal telephone line, so you call up a web sites in the normal way, but the data from the site comes flying back to you at incredible speed, over a digital satellite channel. Data is compressed into ‘packets’ and coded, so only your Internet box picks it up. The enormous capacity of digital satellite channels means thousands of people can use it at the same time. There are even plans for two-way satellite communications, but that’s some way off.            

 

 

TV/VCR AND SATELLITE QUERIES

 

RIGHT STUFFED

Name              Andy Hawkins, Bedford, Beds                                   

Kit                   Akai VS-G815 VCR, Technics A900, Tannoy 632s   

Problem            When listening to NICAM broadcasts though the VCR Andy complains that he hears a high frequency noise, he describes it as ‘squidgy’ which we take to mean it changes in frequency. It only comes from the right-hand channel and is most noticeable during the gaps between adverts. It disappears altogether when he switches to the left channel.         

 

Expert Reply             Andy goes on to ask if it could be anything to do with his aerial or the downlead cable?  This seems very unlikely, everything points to misalignment or a fault on the NICAM decoder in Andy’s VCR. NICAM faults are quite rare, decoders are pretty reliable, and mostly they either work or they don’t, in-between faults like these seldom occur. Likewise, transmission errors are unusual, the NICAM signal is quite robust doesn’t suffer from problems with reflected signals to anything like the same extent as conventional FM TV sound. In any case, transmission faults are rarely confined to just one channel. However, there’s an easy way to isolate the fault to the VCR, and that’s to check NICAM sound on a stereo TV or another NICAM VCR.

 

DISPLAY DESPAIR

Name              Kane Williams, funkyman51@hotmail.com                                   

Kit                   Sony KV32WF1     

Problem            The selection of widescreen display modes on his recently acquired Sony TV are a big disappointment to Kane. There’s only four to choose from, 4:3, wide, zoom and smart. He says wide still gives black bars at the top and bottom of the picture, smart is not smart at all, it’s useless, he adds. Zoom is the correct mode for widescreen and Cinemascope programs, but what about all the other display modes? His set just can’t cope. His suggestion is to have a semi-widescreen mode, where the image is stretched horizontally, until the picture fills the screen vertically, leaving the black bars at the sides of the picture.

 

Expert Reply             Kane’s semi-widescreen mode is a good idea but we can foresee difficulties in processing such an image and it’s likely the cost would be prohibitive. Maybe Sony was trying to be a bit too clever with their ‘Smart’ mode. We have to agree it doesn’t always get it right. The problem is there are so many different TV and film display formats  – we can think of at least ten  -- it would be impractical for TV manufacturers to try and cater for them all. There is no easy solution, short of fitting widescreen TVs with manual zoom, pan and scan controls, so the viewer can decide on the size and shape of the picture. One day maybe?

 

PORTABLE PLAYBACK

Name              W.D.Cooper,             Nailsea, North Somerset

Kit                   Mitsubishi HS-710B mains battery VCR   

Problem            With so many front projectors now coming on to the market, Mr Cooper asks is any of the VCR manufacturers are planning to bring back portable decks? He says there must be a market for this type of VCR, to use and carry around. His own Mitsubishi HS-710 mains battery VCR, is still in regular use, with an early Sharp video projector.       

 

Expert Reply             I had to delve deep into the archives to remind myself of the HS-710. I reviewed it back in 1985, just after it replaced the HS-710 portable deck. Its principle claim to portability was the fact that it had a handle, and would run for an hour or so on an internal rechargeable battery. It sold for the princely sum of £525. That was a lot of money. Back then you could get drunk for half a crown, and still have change for a packet of five Park Drive. Happy days…However, I was reminded that it weighed 7.2kg all up, which is getting on for twice as heavy as most living-room VCRs nowadays. I suspect the 710 and its ilk disappeared because the market for luggable battery-powered VHS decks was and is very small. It’s not as if you’re going to set up in a field, in any case you’re going to need a mains supply for the projector. You could always use a camcorder for portable playback; they’re small, light and comparatively cheap. You can record directly to VHS-C tapes, using an adaptor in a VHS VCR, hour-long. EC60 tapes run for a couple of hours at LP speed. Admittedly it’s not so easy to record, or transfer recordings to 8mm tape, unless you have a homedeck. EC regulations have taken care of that. Camcorders with an external recording facility are officially classified as VCRs, attracting a higher duty and affecting quotas.

 

TRACK TRAP

Name              Paul Coultrup                                             

Kit                   Akai GS-745 VCR, Aiwa NSX-AV75 mini DPL system   

Problem            Paul’s new Akai VCR is suffering from the same sort of purring sound that so irritated Nigel Denny in the February episode of Hints & Tips. He also noticed it when replayed recordings on an ageing Sony VCR, though it only seemed to affect some tapes, others were okay.     

 

Expert Reply             It’s almost certainly the same root cause, mis-tracking on the original recording. VHS video recorders with stereo hi-fi sound systems are very sensitive to mis-tracking, which is why all of them now have automatic systems that continuously monitor, and compensate for errors. However, if the errors fall outside of their range of adjustment, the sound will start to suffer, and the first symptom is often the purring noise Paul’s hearing. The fact that it’s happening on two VCRs suggests the problem lies with the affected recordings, though since Paul’s VCR is only 5 weeks old, it’s worth having it checked, just in case. He should take a long a tape or two, so the engineer can confirm the effect for themselves. Most VCRs can be persuaded to re-track, a few have manual overrides, but that’s all you can do, apart from switching to mono sound.            

 

DREDDFUL NOISES

Name              D. Gournell, Dgournell@aol.com                        

Kit                   Panasonic DPL TV, Sony SLV-E700 VCR     

Problem            Mr Gournell is bothered by loud popping and crackling noises on mainly pre-recorded movies.  It’s worst on films, like Judge Dredd and Independence Day, others are not so bad, but he says it can become tiresome. He would like to know if it’s a fault with the VCR, or the TV?

 

Expert Reply  It would have been helpful to know the make and model of TV, but that’s usually where the problem lies. The most likely suspect is over-modulation or clipping on the Dolby Surround soundtracks, during loud effects. In the olden days the solution was to adjust the input level on the Dolby DPL/Surround decoder. However, input level controls, especially on decoders built into TVs, have all but have disappeared. It’s unlikely there’s one on Mr Gournell’s set, though it’s worth re-checking the manual. If not he can try reducing the level, before it gets into the TV. A simple audio mixer, like the ones used for editing home video movies, is one possibility. They’re fairly cheap, Maplin Electronics and Tandy stores sell them for less than £20, the Maplin one comes with a SCART adaptor, so it’s quite easy to fit in the audio line connection between the TV and VCR.             

 

BOX COPY 1

GETTING STARTED -- THE ART OF SCART

All TVs, VCRs, DVD players and most satellite receivers sold in the EC have to be fitted with 21 plug SCART AV sockets. But why? The rest of the world seems to get by perfectly well with simple push-fit phono sockets (aka RCA and cinch sockets), for audio and video connections. SCART plugs and sockets are bulky, fully wired cables are thick and unwieldy and the quality of connection can be noisy and unreliable.

 

SCART has an unusual history. It started life in the early 1970s as an obscure multi-pin connector known as Peritelevision or ‘Peritel’.  SCART stands for Syndicat des Constructeurs d'Appareils Radio Recepteurs et Televiseurs, a consortium of European manufacturers and standards organisations that adopted it as an Euro standard back in the early 1980s. It was an attempt to simplify and integrate AV connections between TVs and video recorders and provide a means for electronic devices to communicate with one another. It received enthusiastic backing from companies such as Philips -- who dubbed it the Euroconnector. Far Eastern companies were not so happy, though as they had to fit SCARTs in order to sell their products in European markets.

 

No one really likes it – apart from plug and cable manufacturers – it’s pretty hopeless and plugs keep on falling out. There are plenty of better alternatives but it looks as though we’re stuck with it for the time being, at least. Multi-pin connections will be unnecessary with digital AV equipment. A single serial optical or RF connector using the shiny new FireWire (IEE1394 to its friends) digital interface can carry video, audio and control data.

 

LD AND DVD QUERIES

 

BREAKING THE CODE?

Name              Mark Price, Penn, Wolverhampton                   

Kit                   Sharp video projector, Kenwood KRV-990 amplifier, Panasonic NV-HD-610 VCR   

Problem            A keen home cinema enthusiast – Mark has converted his loft – he is now thinking ahead to DVD. Being a little impatient he went ahead and brought a Dolby Digital amp, which caused him to sweat a little until the recent announcement, that MPEG audio wouldn’t be mandatory on European Discs, but now he wants to know if this decision is going to affect regional coding. He wonders if he buys a European DVD player that can handle Dolby Digital/AC-3 sound, will it also be able to play discs imported from the US?

           

Expert Reply             The decision to allow both Dolby Digital and MPEG audio on discs sold in Europe has nothing to do with regional coding. The Hollywood Studios are still insistent that they want to be able to control release dates and the distribution of their movies, moreover, regional coding enable Governments and censors to dictate what you can, and cannot see. In other words, you still will not be able to play a regionally coded US disc on a European player; however, it is our guess that it won’t be long before multi-standard players appear in the shops.  The debate over sound standards was always a side issue and we’re pleased that it has now been resolved. 

 

DIRE VIDEO DISC

Name                          Sally Hamilton, Stevenage, Herts              

Kit                               Pioneer CLD-925 laserdisc player wondering about DVD

Problem                      So far Sally has seen two DVD demonstrations, once last year at a trade show, and more recently on a holiday to the US. On both occasions she says the quality was poor, not a patch on her beloved Laserdiscs, so what’s all the fuss about, she wants to know?

 

Expert Reply             DVD demos, especially in the early days, were notoriously flaky. We’ve seen decks connected to poorly adjusted TVs in abysmal lighting conditions and quite often the demo discs themselves were pretty ropy. Much of this was down to the original encoding, which if not done carefully, produces various artefacts, like blocking, shimmering, blurring and colour banding. That simply shouldn’t happen any more. DVD has the potential to be even better than LaserDisc; in fact on a good day it’s close to broadcast quality. That’s what we can expect, nay should demand from the format. Hopefully shops and stores selling DVD will put a lot more effort into demonstrating it properly. A well set up DVD presentation on a big screen TV should make you stop, take notice and fondle your wallet!

 

WET WET WET…

Name                          Mick Hawley, Croydon, Surrey            

Kit                               A rather sick Philips CDi-210DVC

Problem                      A cup of coffee, perched on the top of Mick’s TV was knocked off by his cat – so he says – with the contents landing on his CDi player. He managed to switch it off quickly and dried it off, on the radiator. He says he left it for a couple of days, then plugged it back in, there was a puff of smoke and the fuse blew. He replaced the fuse but it kept on blowing. Given that CDi is now just about dead in the water he wants to know if we think it’s worth having the deck repaired?

 

Expert Reply             It really depends on how many and what type of discs Mick has, and whether or not he wants to keep on using and watching them. In any event it’s worth getting an estimate for the repair, it might not be too serious. If it comes to more than around £50 or so then he might be better off looking for a second-hand player. The other alternative is to save up for a DVD deck. Whilst it’s not part of the spec we expect several models destined for the UK will support the White Book standard and be able to play Video CDs. There was a rumour some time back that Philips were working on a DVD deck that could handle CDi discs as well. However the good people at Philips UK didn’t seem to know anything about it when we spoke to them recently.            

 

PIONEERING SPIRIT

Name                          Jason Milford, Redhill, Surrey            

Kit                               Pioneer CLD-950 laserdisc player

Problem                      Which video output socket should he use? Jason recently acquired his Pioneer laserdisc player from a friend, but it came without an instruction book. He is very pleased with, it works beautifully, and he has managed to figure just about everything out, but he can’t work out why it needs three video outputs – two on the SCART sockets, and one on a phono socket. Is there any benefit in using the phono socket – compared with the SCART – does it provide a cleaner signal, for example, and would it be a good idea to use high-grade audio cables instead of the cheapie stuff that comes with AV products?

 

Expert Reply             The same signal is present on all three sockets, it’s a standard one volt (peak-to-peak) composite video signal, the SCART standard includes provision for separate RGB or Y/C (S-Video) signals, but they are not used in this application. Reading between the lines it sounds as though Jason might be wondering why LaserDisc players don’t have other types of video output, like RGB (where red, green and blue colour information is handled separately) or S-Video (brightness and colour signals – ‘Y’ and ‘C’ -- are processed separately). The simple answer is that higher-performance video schemes only pay dividends when used throughout the system, from source to display. The video signal recorded on LaserDiscs used the standard composite video system, where colour, brightness and synchronisation signals are all mixed in together. Changing a composite video signal in into RGB or S-Video signals is difficult and in the end would have little or no impact on picture quality.

 

As far as leads are concerned, no, there’s little point using high quality audio cable as this is optimised for much lower frequencies and can be very expensive. By all means pay a little more for well made video cables and connectors – gold plating ensures a low-noise, long-lasting electrical connection -- but don’t expect to see any significant difference on the screen. 

 

BOX COPY 1

GETTING STARTED – THE NUMBERS GAME

DVDs look, feel and smell like ordinary audio CDs but there are a number of important physical differences that may not be apparent to those of you without high-powered microscopes. The main one is that DVD is like a sandwich, with 0.6mm thick substrates, or laminates bonded together, whereas audio CDs have one substrate, 1.2mm thick. This arrangement has two big advantages; firstly the laser doesn’t have to travel so far into the plastic, to reach the reflective layer(s). This means players can use a shorter wavelength laser with a shorter focal length optics, giving improved focusing precision. Secondly, twin laminate discs are not as sensitive to changes in temperature, so they’re less liable to deform.

 

Unlike CDs, the reflective playing surface on DVDs can be made up of two separate layers. Moreover, because discs can be double sided, you can have up to four layers per disc. It’s easier to understand if we put some numbers on it. A standard audio CD can store around 650 megabytes of information. DVDs use finer reflective pits and a more tightly focused laser to cram much more information into the same physical space. For example, a single-sided, single-layer disc has a capacity of 4.7 gigabytes, or over 7 times as much as an audio CD. A single-sided dual-layer disc manages to squeeze in 8.5 gigabytes, a double-sided single-layer disc can hold up to 9.4 gigabytes and a double-sided double-layer disc has a 17 gigabyte capacity. That means video playback times of 133 minutes, 242 minutes (4-hours), 266 minutes (almost 2.5 hours) and 484 minutes or just over 8 hours.  

 

[Home][Software][Archive][Top Tips][Glossary][Other Stuff]


Copyright (c) 2005 Rick Maybury Ltd.

admin@rickmaybury.com