How the Revolution will be Televised

16th October 2008 by Tim Jarman

Big changes are happening in television technology. Like many manufacturers, B&O are hedging their bets by offering a choice of dislay types: plasma and LCD. What are the advantages? Why are these changes happening? Have we been here before?

Within the last few years, a combination of scientific advance and manufacturing skill has delivered one of the long term goals in television design, the large screen flat panel display. Prototypes and mock-ups of these devices were shown by all the major manufacturers for at least the last twenty years and have been a feature of science fiction films for even longer, but now they are a practical proposition that can be bought as a consumer product. That is not to say that all the problems are solved, the ideal would be a device that is as light and slim as a framed picture that can function on very little power and without any external equipment, something that the current generation of heavy, bulky and power hungry models cannot yet achieve.

The change from cathode ray tubes (CRTs) to flat panel displays brought with it a new range of Beovision models which started with the plasma BeoVision 5 and the LCD BeoVision 6. Within a few years of their introduction, B&O had phased out all its CRT television models. However, this is not the first time that the Beovision range has been completely revised to take account of new technology.

When television sets as we’d recognise them now first appeared in the late 1930s the standard screen size was 12” (or 9” for the smaller, cheaper models). Unlike the compact displays of today, an early 12” tube was a formidable piece of industrial glassware, two or three feet long and capable of explosive detonation should the fragile glass envelope be breached, causing the vacuum inside to fail. Before long, some manufacturers added smaller 7” and even 5” models to keep the costs down. Smaller tubes were cheaper to make, required less complex driving electronics and could be enclosed in smaller, cheaper cabinets. However, since this time screen sizes have grown larger and larger. At the start of the colour era in the late 1960s the largest standard monochrome tube had a screen size of 23”.

The Beovision 3000 was very much a “first generation” European colour receiver and therefore used a 25” tube. As well as offering colour, the Beovision 3000 offered a considerably larger picture than viewers would have previously been used to. The extra screen size and the complexities of colour came at a price; the Beovision 3000, like all early colour sets, was very deep and consumed a great deal of energy. However, the pictures it could produce, even at this early stage, were beyond reproach. A well preserved example can still produce results that are up to current standards of quality (and in some cases beyond). The aims of television design at this stage were threefold: firstly to reduce the cabinet depth, secondly to reduce the power consumption (something that usually goes hand in hand with improved reliability) and thirdly to reduce the cost of the complete receiver.

The Beovision 3400 answered the first of these questions with its 110 degree “Phase II Delta” tube. This made the depth of the cabinet more manageable, though those few precious centimetres came at the cost of greater complexity. Although the Beovision 3400 was undoubtedly and excellent performer it was not renowned for reliability at the time.

The next generation, typified by the Beovision 3500 and Beovision 6000, addressed the reliability issue by replacing the remaining valves in the circuitry with cool-running transistors. This halved the power consumption at a stroke and lead to sets that could function unattended for many years. The widespread use of integrated circuits (also known as “silicon chips”) in these models also reduced the component count, making for more compact assemblies and cheaper overall costs. These changes allowed the cabinets to be slimmer and more shapely; the Beovision 3500 of 1974 occupies barely any more floor area that today’s BeoCenter 6-23 and produces a larger picture.

The next big change was the “in line” tube. This appeared in the Beovision 4402 (and derived types), though smaller sizes had been available in other manufacturers’ sets for some years previously. The in-line tube, unlike its “delta gun” predecessors, did not need a set of complex adjustments to be made every time the set was moved (and as the tube aged) to give its best performance. This made the sets simpler, cheaper and easier to maintain. For the first time one could buy a set in a sealed carton, take it home, plug it in and get a perfect picture straight away. This turned the television into a simple and perfect “consumer product” because it did not need the co-operation of an understanding and tolerant dealer to keep it in good order.

Later Beovision models refined these principles. The 33XX range of 1980 offered a well developed remote control and utter reliability. The 77XX models which followed took account of the new desire to connect peripheral equipment such as video recorders, home computers, cameras, video disc players to a television. In the late 1980s, the LX models introduced the “flatter squarer tube” (FST) and digital stereo sound and the mid 1990s BeoVision Avant was the first B&O model to offer the new 16:9 “widescreen” format.

Each of these changes has addressed a problem or disadvantage that was a feature of the previous generation. It should be noted though that there was never a real breakthrough in picture quality: that has gone up and down over the years by small amounts and probably as of today peaked with the 77XX sets of the mid 1980s. What has improved fairly continuously over the period just discussed was cost and to a latter extent the convenience of ownership. Cost is only of interest to those in the market for a new set. Once paid for, the price becomes somewhat irrelevant until a replacement is required. Convenience is different matter and really boils down to reliability, replacing an old and troublesome set with a new one which functions perfectly year after year is always attractive. However, most manufacturers, B&O included, had the reliability problem licked by the late 1970s and have in most cases managed to produce a consistently reliable product ever since.

The advantage that the new generation of flat-panel sets offer is not one of greater reliability, better picture performance, improved flexibility or greatly lower energy consumption. They offer in the main the possibility of a really large picture in a package that is domestically acceptable. Even modern wide-angle CRTs become unmanageably bulky in sizes greater than 28” (normal) or 32” (widescreen). Flat panel displays only become larger in width and height, the depth remains largely constant regardless of screen size. Very large CRTs also struggle to produce a picture of perfect geometry and consistent overall focus when made very large, something that the current generation of plasma and LCD displays are not affected by. The BeoVision 4 plasma can be ordered in a 65” size that offers more than four times the screen area of the largest of the LX models. The increase in screen size is truly dramatic when one realises that the largest 4:3 screen that B&O offered was the 66cm of the 28” LX range (e.g. the LX 2800, LX 2802, LX 5500 and LX 6000) was little bigger than the 63 cm of the original 25” Beovision 3000 made over twenty years previously.

Given that the advantages offered by flat panel models are mainly concerned with screen size, one must question the wisdom of the smaller models. The BeoVision 6-22 was not much more compact than the MX 4200 it replaced and was a poor performer when compared directly. Both can be mounted on a table, on various floor stands or hung on the wall and both offer a similar range of facilities. The reason for the replacement of one by the other in this case is fashion, the years of development that have gone into the CRT set have been swept away because the cabinet is the wrong shape.

What of the future? The next “big thing” is high-definition or “HD”. HD sets offer better resolution than previous types as an HD picture is composed of more pixels than a 625 line picture produced by the PAL system that the UK uses. HD is hailed as a revolution in itself but like many features of modern life one must cut through a lot of hype to uncover the real hard facts. HDTV has been made necessary by the larger screen sizes of modern sets. The normal TV signal simply does not contain enough information to properly produce a 65” picture on a set which is to be viewed at close range, so it has become necessary to add extra information to produce a picture that can be watched comfortably. Isn’t it odd that TV sets have been getting bigger as rooms have been getting smaller? Most domestic TVs cannot even produce the full definition of the normal transmitted picture, this would make them prohibitively expensive. Even a Beovision seems cheap when compared to the cost of a grade 1 broadcast monitor!

Moving on a few years, new display technologies will emerge to rival LCD and plasma. Of these, OLED seems to offer the most promise, dispensing with the complexity of plasma and the power hungry back light of the LCD. It is tempting to think that the pace of development is increasing but in practice this is not really the case, these sets will offer some advantages over those currently available (probably they will be even thinner, lighter, use less power and provide slightly more contrast) but the improvement is unlikely to be anything like that which was made in the first ten years of colour, which started with a set that was so expensive that it could only be bought by the lucky few, required two strong men to lift and needed regular service calls to keep working and ended with compact, reliable models that could be set up and used by anyone and were cheap enough to have become a feature of most homes.

A problem that the B&O designers will always face is that because B&O sets are durable there are always older models around against which the new ones can be judged. This is how it was noticed that the first transistor colour sets lacked contrast and “punch” compared to the valve ones, that the early LXs were not very reliable compared to the 33XX models, that some of the tubes used in the Avants had a disappointingly short life and that the first LCD models were really not that good at all.

Despite these small setbacks, one can be sure that whatever technology is used, Beovision sets will show it at its best. That’s one thing that’s never changed.