REVIEW

UNIVERSAL REMOTE CONTROLS

INTRO

Are your black button-boxes breeding?  Put a stop to it now with our exclusive guide to remote pest control

COPY

Remember the days when you had to get up out of your chair to switch channels, adjust the volume or turn the telly on and off? Probably not if you're under thirty; remote control has now become a way of life, and it's surely only a matter of time before button-finger, remote wrist and couch potato's bum become recognised medical conditions.

It's a relatively new phenomenon; ten years ago remote control was still being sold as an option on mid-market televisions, these days they're a standard fitment, not just on cheap TVs but everything from car-alarms to vacuum cleaners -- yes, you really can get them... All well and good, but it has meant a serious proliferation of little black boxes. Many households now have three or four of  them running around the living room, getting lost down the backs of chairs or chewed by the dog; it's going to get worse but there are ways of humanely culling their numbers, which we'll come to in a moment. First, though, a short history lesson.

Remote controls, as we know them today first appeared in the late seventies on televisions, VCRs and hi-fis came a few years later. Up until that point the front-panel controls on TVs relied mostly on analogue technology. In other words, as you turned a knob a variable resistance (or  potentiometer) altered a voltage in a circuit, which made the volume go up and down, or change the brightness, and so on. Until the mid 70's most TV tuners used analogue circuitry, with rows of chunky push-button knobs that had to be delicately twiddled for each channel. None of this was especially conducive to remote control; nevertheless most TV manufacturers developed elaborate motorised knobs and servo-operated channel selectors, but they tended to be expensive, and rather unreliable.

SONIC SUCCESS?

Those early systems generally used two types of  remote link; the simplest method was the 'hard-wire' or cable remote, basically a little box with knobs and switches on the end of a long wire. The casualty rate was very high, trailing cables were chewed up by Hoovers, or ripped from their sockets as people tripped over the lead. The first successful 'wireless' systems used ultrasonic, high-frequency sound waves well above human hearing range; though not cats and dogs, as pet owners and spiteful little boys quickly discovered. The other problem with ultra sound is that it's generated naturally by all sorts of things, and the technology wasn't sufficiently well developed to filter out the random high-frequency noises made by jangling keys, breaking or cracking glass and probably screeching bats as well. In short anyone with a TV with ultrasonic remote control had to put up with all sorts of antics as channels and volume levels changed for no apparent reason.

Twenty years ago two almost simultaneous developments made remote control a viable proposition. The first one was the rapid change from analogue to digital control systems in TVs. It was a by-product from the burgeoning microchip industry and feature-crazy Japanese consumer electronics manufacturers who were attempting to cram as many TV circuits as they could into ever smaller numbers of chips, primarily to drive prices down, and increase reliability. The end result was that instead of twiddling knobs, you pressed buttons, to make things happen and gracefully undulating voltages were replaced by rapidly changing numbers. Doing away with mechanical switches and knobs made the implementation of remote control that much easier, but ultrasonic remote links simply couldn't carry the amount of data needed to operate digital control systems, nor were they reliable enough. Then, by happy coincidence, along came the infra-red light emitting diode or LED and a whole new generation of inexpensive optoelectronic devices. Light has an almost unlimited capacity to carry information, it's almost incorruptible and moves around very quickly. It was a marriage made in heaven and the fruits of that union are now clear to see.

That brings us more or less up to date. Remote controls can be fitted to almost anything, so they are. A few electronics manufacturers have even begun to recognise that there is a growing problem for the consumer and several strategies have evolved to lessen the number of  boxes needed per household.

UNIVERSAL SOLUTION

The earliest attempt was to unify the remote control systems across a particular manufacturers range, so the handset that came with the VCR would also control the main functions on a TV of the same make. One or two companies took an alternative approach and installed links between  the control systems of various components, so they could all be controlled from one box, even if part of the system was in another room. Both solutions are fine, as far as they go, but what happens when the consumer mixes and matches products from several different manufacturers? They've thought of that one too, and several TVs and VCRs now come with multi-brand remote handsets, programmed with a selection of command codes for other manufacturers devices.

That's reasonably easy to do with TVs and VCRs, it's a relatively compact and communicative industry, but with the growing interest in home cinema and integrating audio and video equipment of mixed vintage, from another couple of dozen companies, unified or multi-role remote control becomes a nightmare. Once again, though, there are solutions. The first is the pre-programmed universal remote control which has a massive library of IR commands stored on an internal memory chip. The alternative is the 'learning' IR handset, which simply copies the commands from an existing button box; both types have two or more memory 'banks', each one assigned to a particular product (VCR, TV, satellite receiver etc.). Generally speaking learning remotes cope better with  the more obscure products or systems that contain a wide mixture of devices,  but remember, the original handsets must be in good working order. Pre-programmed remote handsets are better suited for replacing lost or damaged  handsets, but the extent of the code libraries varies considerably, so check to make sure the devices you have can be controlled, before you buy.

BOX COPY ONE -- TECHNO GHETTO BOX

Although we humans can't see infra-red light video cameras can, so if you want to see what's coming out of one of your remote control handsets simply point it at a camcorder lens, and watch it through the viewfinder. Normally you will see a series of brief flashes or pulses of light, every time a button is pressed; on some systems the flashes are so fast the burst of light may appear continuous. Those pulses contain two separate items of information. The first one is known as the framing code, it's the handset's way of identifying itself, so it will only be recognised by the piece of equipment you're trying to control, other devices within range should -- in theory -- ignore it. The next sequence of pulses is rather grandly called the word, and this contains numerical data, in binary form, that relates to the specific command or button being pressed. All of this information is generated by a dedicated controller or encoder chip, in the handset.

At the receiving end the pulses are picked up by a light-sensitive diode, amplified, filtered and fed to a second specialised chip or decoder. The chip then converts the serial data -- i.e. the stream of pulses  -- into parallel form, which can then be understood and interpreted by the host device's microprocessor or control system.

There's surprisingly  little interaction between remote controls meant for different products. In the past manufacturers tended not to talk to each other when they developed new control systems -- they do so now only grudgingly  -- so at the moment there are at least twenty different systems or protocols in use, and that's just on consumer electronics products, like TVs VCRs and hi-fis. Fortunately most newer systems have better built-in protection, moreover, IR systems also have a relatively limited range and sensors tend to have a quite narrow field of view. If problems do occur the two devices can be separated, or de-sensitised by re-orienting them, or putting some tape over the IR receptor window.

BOX COPY 2 -- WHAT'S AVAILABLE?

FOX 400E £39.95

Comprehensive pre-programmed remote combining the control functions for  two TVs, a VCR and satellite receiver. One of the few handsets to have fastext facilities, but little to interest the AV system user. Very easy to set-up and use.

MEMOREX AV4 £29.99

Pre-programmed handset with codes for many of the most popular makes of TV, VCR and satellite tuner. Sufficient capacity to replace up to four other handsets, reasonably simple to program but not so easy to use due to tiny buttons.

MEMOREX AV8 TURBO £59.99

The AV4's big brother, with increased capacity, to control up to 8 devices, including a large number of hi-fi systems, AV amplifiers, CD, DAT and cassette decks plus surround-sound systems. Relatively easy to program but hampered by even more titchy buttons

ONE FOR ALL 4 £29.99

Neat-looking pre-programmed handset covering up to four separate devices (TV, VCR, satellite receiver and one other). Large code library which covering a wide range of products but some gaps and a bit variable on audio components

ONE FOR ALL 6 £49.99

Sophisticated pre-programmed remote for up to six devices. Covering a vast number of products, including many hi-fi components and systems. Programming system fairly convoluted for devices not listed but there's very little it can't control, one way or another.

PHILIPS RT-830 £99

The jury is still out on this one. It's the first voice-controlled learning remote. Once programmed it will respond to verbal commands, but as you still have to press a button to make it work, it offers little relief for terminally lazy couch potatoes. Designed to operate TVs and VCRs it can even be used to make timed recordings. Voice recognition facility a bit hit and miss -- try to stay calm if it ignores you -- but a lot of fun, albeit at a price.

VIVANCO ULR 100 £19.99

Good value learning remote with four memory 'banks', giving a total of 124 pre-settable commands. Useful macro facility, to store a sequence of up to 10 commands -- to turn on the TV and VCR, and set it to play, for example, with just one button push. Easy to teach, let down only by small buttons.

VIVANCO UPR 100 £29.99

Versatile pre-programmed handset covering up to five devices. Extensive code library covers most TVs, VCRs and satellite receivers but a little vague when it comes to hi-fi systems and AV components. Good value unifier for basic systems.

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