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Being a naturally suspicious person, Mr Law has no intention of letting any Channel 5 retuners fiddle with his TV or video recorder. He has a Sony VCR with a channel display and has checked to find which alternative channels he can use for his VCR and satellite tuner. He thinks that only channels 34 and 40 are free in his area but he fears channel 34 will become unusable when C5 starts broadcasting. With only one spare channel available he want to know what can be done, and what provision he can make for a laserdisc player or DVD deck.


Expert reply:

No worries! Channel 5 interference wonít be a problem if you connect your equipment together using SCART AV leads. You might need to re-tune the VCR, to avoid a channel clash with C5 and your TV Ďvideoí  channel but itís unlikely youíll only have two free channels to play with.  C5 tuning wonít be an issue if you get a laserdisc or DVD player as youíd be mad to connect them to the TV using the aerial lead. The whole point about these devices is the improved picture and sound quality, which would be barely noticeable using an RF link (the audio will be mono too). If your VCR has 2 SCART sockets you can route the satellite tuner through it, otherwise the VCR will have to go through the satellite tuner -- most current models have three  SCART sockets -- with the connections clearly identified. If youíve got older or more basic equipment -- i.e. with just one SCART socket per box -- then either think about upgrading, or get a SCART switch-box.



Name  Henry Kavanagh, Tenby

Kit            Toshiba 2857DB DPL TV, Sony SLV-E710 VCR



Henry is generally happy with his system but feels it lacks impact in the surround-sound department. He wants to know if there any simple add-ons -- hopefully costing less than £200 -- that can improve the sound.


Expert reply:

Henryís system is wholly dependent on the Tosh TV, for DPL processing, amplification and the speakers. Thereís nothing wrong with the TVís Pro Logic decoder, and the amps work well enough but theyíre not very powerful. The supplied speakers -- built into the cabinet  and stand, plus a pair of rear effects speakers -- are simply incapable of creating the kind of wide, dynamic soundstage and surround-sound effects home cinema cries out for. A pair of outboard speakers for the right and left stereo channels, and possibly some more efficient effects speakers as well, would definitely help. The TV has a set of speaker outputs, so theyíre easy to fit and well within your budget. However,  the TVís audio amplifier is the weak link, but unless youíre willing to start again from scratch and spend quite a bit more, on a beefy AV amp/DPL processor, speakers and probably a sub-woofer as well, Iím afraid thereís not much you can do about it.



Name: Paul Myhill

Kit: Sony KV-28W53V, Sony SLV-E80 VCR


Problem: Paul thinks he might have a problem with his Sony widescreen TV. Channels 1, 2 and 3 are fine, however, the picture on Channel 4 is rather grainy, he compares it with looking through a dirty window, and he says the sound only ever seems to be in mono, with the odd burst of NICAM. He says he has tried re-tuning several times without success, and has also tried an aerial booster, which made a small improvement to the picture, but not the sound.


Expert reply

The very slight frequency difference between C4 and the other channels is unlikely to be the cause, so itís almost certainly not the TV. I checked with the ITC engineering department and they confirmed that the Belmont transmitter, which serves your area, has not suffered any power reductions recently, and that C4 operates at the same power levels and polarity as the other three channels, so itís not their fault either. That leaves just one or two other possibilities. The most likely one is a reduction in signal strength brought about by standing waves. This is usually a very localised phenomenon, often caused by a reflected signal path, reacting with the direct signal from the transmitter. The two signals effectively cancel each other out. The cure could be something as simple as moving the aerial a few feet. Check with your neighbours, to see if theyíre suffering too. If not you might like to try running a feed from their aerial -- you can get long extension cables from most electrical retailers and woollies. If that does the trick then a call to your local aerial installer is in order. If not your best bet is the local exorcist.



Name Steve Walker, Watford

Kit:  JVC HR-D725



Steveís old JVC HR-D725 VCR is doing some very strange things. All of the segments in the front-panel display are brightly lit and the machine only plays back for a few moments, at high speed, before shutting down. He wants to know if itís a fault and if so, is there anything he can do as he reckons heís quite handy with a soldering iron.


Expert reply:

Sorry Steve, bad news! Itís probably a goner by now. It sounds as though a regulator transistor in the power supply has turned up its toes, allowing the supply voltage to go sky high, probably taking with it a lot of expensive semiconductors and chips in the process. Itís almost certainly beyond economical repair by now. Get a quote by all means, but I reckon itís going to cost a lot more than the machine is worth, to put it right.



Name Lennie Keene, London SE

Kit            Grundig GRD200 satellite receiver, Amstrad dish



Just over a year ago Lennie replaced his Amstrad satellite receiver with a Grundig GRD 200. It worked perfectly until a couple of weeks ago when the picture started breaking up. Now thereís just a pair of blank white panels, superimposed over the top of an unscrambled picture. He wantís to know if thereís a fault with the dish, or the receiver.


Expert reply:

Probably neither, itís most likely Lennieís Viewing Card is faulty. The way to find out is to check Sky News, TNT/Cartoon Network and QVC which are Ďsoftí scrambled, or unencrypted. If theyíre okay then it is almost certainly the card. Try a full reset first. Remove the card, switch off and unplug the decoder, then leaving it for a couple of minutes. Plug it back in and wait for the Ďinsert cardí message and see what happens. If the fault persists call BSKYB customer services on the number printed on the back of the card. They will normally replace it within a couple of days. They will want your old card though, so itís not a crafty way of getting a duplicate card. If they donít get the original back in seven days theyíll switch the new one off.



Name Greg Learman, Peckham

Kit: nothing yet, but in the market for a widescreen TV



Greg is confused by widescreen TV. Heís been to see a Grundig set, and was suitable impressed, but was troubled by the salespersonís insistence that it would only work satisfactorily when used with a Grundig VCR, which can record widescreen programmes. Can this be true?


Expert reply:

Theyíre pulling your pecker Greg, Grundig TVs might be a bit, shall we say, idiosyncratic, but theyíre designed to work in the real world, where they can end up being connected to just about any make of VCR. Possibly the sales operative was keen to flog you a Grundig VCR as well, but the only possible advantage would be a unified TV/VCR remote control. Donít be fooled by talk of widescreen recording either; the only scheduled widescreen transmissions in the UK right now are on Channel 4, which uses the PALplus system.


The Only VCR with a built-in PALplus decoder is a three grand digital jobbie from Sony. Many VHS machines have whatís fancifully described as a 16:9 or widescreen facility, but this is simply a little circuit that senses when a movie has been recorded Ďanamorphicallyí, where the picture looks as though it has been squashed sideways. When the recording is replayed on a widescreen TV, with a zoom or cinema mode,  the picture is electronically stretched so that it fills the width of the screen, and everything resumes normal proportions. Widescreen switching is automatic on TVs and VCRs with the Ď16:9í facility. Thatís all well and good, but the fact is there arenít any 16:9 movies available in the UK, so the feature is practically worthless.



Name  Mick Bentley, via e-mail

Kit: Philips 284521 NICAM TV, Sony TA-AV590 AV amp B&W Solid Monitor stereo speakers, ex Philips music centre speaker for centre channel



Mick has been using a speaker from a long-retired hi-fi system for a centre speaker in his home cinema system. The speaker is placed on top of the TV, where it has worked well for at least the past six months. Now however, heís noticed a green patch on the top of the screen close to where the speaker sits. Mick suspects itís due to the non-magnetically shielded speaker, but canít understand why it has taken so long to appear.


Expert reply:

Itís likely the magnet in the speaker has been causing the colour staining effect all the time. However, every time you switch the TV on a circuit inside the set, connected to a coil attached to back of the picture tube, briefly generates a collapsing magnetic field, that de-magnetises the perforated metal sheet behind the tubeís face-plate. The Ďdegaussí circuit can eradicate small magnetic fields that build up naturally -- from the Earthís own magnetic field -- and from your speaker, but the fact that itís now showing  up on the screen suggests that either degauss circuit has failed, or the build-up is now too large for your set to handle.


The first step must be to remove the offending speaker, and replace it with one thatís magnetically shielded, and hope that the degauss circuit can gradually clean up the screen. If it canít or itís stopped working then you will need help. TV engineers have access to portable heavy-duty degauss coils; if itís a fault it should be relatively easy to fix.



Name: Andrew Pane, Stirchley

Kit: in the market for a surround sound decoder



Whatís the difference between THX and Dolby Pro Logic? Thatís what Andrew wants to know, and if he holds off buying a home cinema system, will it get any cheaper?


Expert reply:

If it helps, think of THX (the Lucasfilm Tomlinson Holman eXperiment) as a kind of supercharged Dolby Pro Logic surround sound. Itís DPL with knobs on, a set of rigid specifications and enhancements covering the design and construction of surround-sound components, to ensure an even more authentic replication of the cinema experience, in your living room.


Briefly, and somewhat simplistically, it starts with a conventional DPL decoder or active matrix. This is an electronic circuit that unravels surround-sound information contained within a movieís stereo soundtrack and Ďsteersí it, to the appropriate right, left, centre or rear effects channel. Thatís the point where THX circuitry takes over. The right and left stereo channels of movie soundtracks are engineered for large auditoria, THX carefully re-equalises and balances the sound to suit smaller spaces. The rear channel output is treated to Ďtimbre-matchingí, which ensures that it blends in more smoothly with the front channels, as sounds move from back to front, or vice-versa. A process known as de-correlation fiddles around with front and rear channel delays, which helps reduce the distracting effect of centre channel leakage. The THX specification also covers speaker design, to ensure they can handle the full range of frequencies -- especially the bass notes -- that movie-makers use to add impact to  their productions.


That kind of electronic trickery and high performance speakers costs big bucks, and the price of THX equipment is unlikely fall as far or as fast as simpler DPL systems. Buy the best system you can afford, but if you go down the THX route be warned that itís going to be expensive...



Name: Neil Philips, Herts

Kit: Goldstar R-C7001 NICAM VCR, Toshiba Dolby Surround TV, Amstrad SRD510 satellite receiver, Harmon-Kardon AVI-100 amplifier.



Neil is in complete despair. He says every video he rents or buys is a gamble. He has to switch off the stereo soundtrack because of the continuous noise that occurs, a constant raspberry sound coming out of the speakers. His only solution is switch to mono, but he doesnít want to watch the film in mono to begin with. This problem occurs with 90 per cent of the videos he rents or buys, all are genuine (not pirated) copies.


Expert reply:

VHS video recorders with DFM (depth frequency multiplex) stereo hi-fi sound systems are very sensitive to mis-tracking, which produces the characteristic Ďraspberryí sound Neil describes. It only takes a very slight tracking error to make that noise, and you might not see any picture disturbance. Virtually all VCRs nowadays have auto-tracking systems, but they can only cope with minor errors, recorded on the tape. The fact that itís happening with rented tapes, but not with tapes heís recorded (weíre assuming thatís the case), implies thereís something wrong with the deck mechanism, and in particular the adjustment of the tape guides. In severe cases you might spot a tell-tale crease along the edge on the tape. In any event itís a job for an engineer.



Name: William Johnson, Grange-Over-Sands

Kit: Arcam Xeta 2, Arcam Alpha 9, B&W centre speaker, Tannoy 638, Canon S-50, REL Storm, Toshiba 3357DB TV, Aiwa HV-FX1500 VCR



William has a biggish lounge measuring 30 x 13 feet, and is thinking of trading in his Toshiba TV for a Philips 46P912 46-inch rear projector. Alternatively he could keep the Tosh TV for normal viewing and get a front projector. He has a budget of around £2500, he also want to know how much screens cost, and what sort of size picture he can expect.


Expert reply:

Unfortunately William your budget doesnít give you much room for manoeuvre and the Philips rear projection set is probably your best bet. Youíre not going to get much change from £3000 for a half-decent front video projector, though £4000 is a more realistic starting point. Cheaper models tend to be single element LCD types, with lower wattage projection units. As far as screen size is concerned, the skyís the limit. Most Ďdomesticí projectors will throw up an image up to 100 inches across without any difficulty. A suitable fold-away screen will add a further £150 to the bill; if youíre thinking about motorised or sliding screens then reckon on another £500 or so.     


Name: S. Law, Radlett

Kit: Sony TV



Name: G Macdonald, Nottingham

Kit: Panasonic TX29AD1DP DPL TV, Yamaha YST SW60 active sub



Adding the sub-woofer to Mr Macdonaldís Panasonic TV has improved the bass output, but now he wants to do something about the dialogue. This set generates a phantom centre channel from the right and left stereo speakers; he would like to know if replacing the main speakers with a pair of Canon S-25ís will help, and possibly Canon S-15ís for the rear effects speakers.


Expert reply:

The S-25ís are good, but they canít perform miracles and in any case they would be unsuitable for your set-up. Theyíre designed to create a wide, well diffused stereo soundstage, that would tend to dilute the already unfocused dialogue information even further. Using S-15s for the rear channel might improve back/front balance slightly, and help reduce localisation on the effects channel, but donít expect too much. Realistically changing the speakers is not the answer, you really need to re-think the audio side, and consider a separate AV amplifier.



Name: Steven Hodges, Welwyn, Herts

Kit: Yamaha DSP 780 AV amp, Panasonic NV-D100 VCR, Panasonic TX-21MD1 TV, Jamo Centre 200, Canon V100 Surround speakers, Tannoy Oxford LP speakers



Steven is suffering from distorted sound when he plays back recordings through the VCR. He says it only happens at certain frequencies, such as the opening sequence in the X-Files, or the piano music on Murder One. The distortion is evident on the TV speakers, as well as the surround speakers on all recordings (including rental movies) but not off-air broadcasts.  Heís had the VCR checked by an authorised service agent, but they found nothing wrong. Heís also tried changing SCART leads, but to no avail, so now he want to know if we can help?


Expert reply

It has to be the VCR. Youíve proved thereís nothing wrong with the TV or  surround system. Itís doubtful the service agent gave the hi-fi system more than a cursory once-over. Take it back, and this time take a tape along with you, so they can hear the distortion for themselves.



” R. Maybury 1996 0110




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