PUBLIC TELEVISION DISPLAY AT 1938 RADIOLYMPIA

Radio Record, Volume XII, Issue 27, 16 December 1938, Page 47

PUBLIC TELEVISION DISPLAY AT 1938 RADIOLYMPIA

HE Thirteenth National Radio Exhibition-popularly known throughout the United Kingdom by the name "Radiolympia"’-organised by the Radio Manufacturers’ Association, was keld at Olympia from August 24 to September 3 this year. . Exhibitors numbered some 140 firms, including 20 piano manufacturers in a special piano section, incorporated in the exhibition for the first time. Of the 120 exhibitors more directly concerned in the radio industry, some 35 were set manufacturers, 50 component makers, 10 wholesalers, half a dozen. publishing firms, a dozen raw material suppliers, end a dozen or so mekers of measuring instruments and service equipment. The public attendance numbered approximately 145,000.

The outstanding features of Radiolympia 1938 were undoubtedly occasioned by radi- | -eal changes in policy which were applied by the association a this year’s organisation for the first time. Those changes .affected two aspects of the Exhibition. First, the Radiolympia Theatre, in which for many years past performances have been given by favourite radio artists, was ‘discontinued and a television studio substituted for it. Secondly, technical facilities were provided which made possible demonstrations of radio receivers and, also, television receivers on the stands of exhibitors throughksut the Exhibition. The television studio was conceived and carried out in intimate rather than spectacular fashion, aiming to show the type of heme entertainment and the method of its presentation which is regularly provided in the television transmissions from Alexandra Palace. As a result, the crowds -whe threnged previous exhibitions to see the spectacular variety show given in the Radiolympia Theatre were, this year, absent-an explanation, in part, at any rate, of the slight fall in attendances during the exhibition period. Visitors’ Interest In the absence of these visitors, a marked change in the atmosphere of the Exhibition was to be observed, The superficial gaiety and glitter was replaced by a real sense of interest in the goods displayed by the exhibitors. Evidence of this was readily afforded by 2 visit to the gallery, whence a view | of the Exhibition, as a whole, was. to be obtained. It was most noticeable that the crowds were on the exhibitors’ stands in close contact alike with goods and salesmen, rather than gazing from the gangways.

This effect was doubtless due, in large measure, to the arrangement whereby television demonstrations were given ond stands throughout the Exhibition rather than in segregated darkened rooms as in previous Exhibitions. Realisation that tefevision is now a definitely established home entertainment within. the television service area was surely conveyed to every visitor. The arrangement of ike radiofrequency sound demonstration system also helped to achieve this intimate result, for controllable receivers operating on special "local" or "distant" Radiolympia transmissions were, in general, situated inside the stands so that they should only be operated under the exhibitors’ supervision and so prevent interference of one set with another. R.F. Demonstrations The radio-frequency demonstration system merits further description. The idea was conceived a@ year ago by the Radio Manufacturers’ Association and an actual experiment on a small scale was carried out in exhibition conditions at the 19387 Radiolympia. This experiment was so successful that it was determined to rely upon the system entirely for the whole of the 1938 demonstrations. Two. special transmitters were provided, their progammes being distributed to the stands im the Exhibition by the recently developed system of co-axial cahtes. The- stands themselves were equipped with circuits which caused the distributed programmes to duplicate the signals picked up byan average receiving aerial. The two transmissions. were: Radiolympia Local on approximately 375 metres (800 kilocycles), a highfidelity transmission of about 20 millivolts intensity, which simulated the reception of a local BBC station. ‘The other transmission available for sound-broadcast receivers was Radiolympia Distant, on approximately 335 metres (895 kilocycles} which was of lower intenSity (aproximately two millivolts). Visitors were able to use this transmission to judge the selectivity of the receivers. Television As already stated, it was found possible at the Exhibition for the first time to demonstrate television receivers on the stands in the main exhibition, so that visitors could examine them with the minimum of difficulty. and formality. The Radiolympia television transmissions were extended beyond the normal BBC television transmission times and visitors were able

to see televisors working at practically any time during the hours of the exhibition, These transraissions were picked up from Alexandra Palace by an aerial on the roof of Olympia, and distributed to the exhibitors’ stands by means of apparatus such as is used for community aerial operation, in blocks of flats, ete. The quality of the demonstrations was uniformly high. The pictures received were bright, clear, with geod. tone gradation, and free from filicker. They showed substantial improvement on the standard of 1937, at a very reasonable price level. ~ Part of the programmes originated in the Alexandra Palace studios; part were sports outside broadcasts including the final stages if the last Test Match at the Oval, transmitted to Alexandra Palace by ultra-shortwave radio link. Another part, of particular interest to visitors, originated in the, Radiolympia television studio. Here visitors were able to see the programmes direct, to see the BBC apparatus and studio equipment, and then to see the prégramme- as transmitted via, a special television cable to Alexandra Palace, whence it was radiated to viewers in Olympia and outside. A small tele‘vision transmitter was provided in Olympia to serve as a stand-by, allowing the Radiolympia studio programmes to be distributed direct to the Exhibition, instead of via the cable to Alexandra Palace, and then by radio back again to Olym pia. This provision was made to take care of contingencies which might otherwise interrupt the demonstration of -the television receivers.

Broadcast Receivers Turning to radio broadcast reeeivers, while sound design and good workmanship were as marked as ever, the most spectacular. of the improvements made during the year certainly had to do with tuning. This has been made-almost magically-an automatic process. Simply by pressing one of a numper of buttons, or by dialling a number (as with an automatic telephone), the desired station is tuned in. Simple devices were: also provided whereby the station selected by the individual push buttons could be changed, very simply, at will. The variety of receivers with automatic tuning displayed in the exhibition was extremely wide. From the region of .2 guineas right up to-150 guineas it was possible. to progress from a simple telephone dial set to the other extreme of an automatic . record changing push-button radiogramophone with a remote control pane} of push-buttons that could be operated from an = armchair, yards away from the instrument itself, Whilst automatic tuning was _the most spectacular new feature, United Kingdom manufacturers have worked as hard, and as sueeessfully, on many other aspecis. Particularly is this true in regard to shortwave listening. The latest sets have continued the progress .of recent years in this direction. In these modern sets the old bugbears of "fading" and "atmospherics" have been largely. overcome. Quality reception and faithful reproduction are other ‘outstanding features. of the products .of the United Kingdom radio industry. | Eliminating Interference | These developments in television and shortwave | reception -have carried with them close study of the prohlems of interference. United Kingdom manufacturers have devoted much research to this maiter and have developed a range of’ anti-interfer-

ence devices, ineluding special type aerials, and equipment for use both at the receiving end and also at the interfering so2rce. This is a.matter which assumes more and more importance as radio reception increases in popularity. The question of tropical use raises a problem to which special consideration has been given and many United Kingdom firms are producing receivers specially designed and finished to meet tropical conditions, Whilst the United Kingdom set is now suitable in type for use in any quarter, that does not mean that the particular requirements of individual markets do not receive consideration. Many manufacturers make a point of producing special models to suit particular overseas markets, such special models being variants of the standard types which can now be made quite quickly and at little extra expense, International Valves. To a considerable extent the development and use of the "International Valve" by United Kingdom manufacturers has assisted in the progress of recent years. By the use of these valves, United Kingdom manufacturers

are able to supply such sets that service problems are simplified and testing equipment already existing in overseas markets will be useful for United Kingdom made receivers also. For those markets where sets making use of vaives of the old standard United Kingdom type are still favoured, these "ill be continued by the manufacturers and no difficulty in the supply of these types is likely to be experienced. Export Committee The United Kingdom manfat. turers, as a whole, are now taking &@ much greater interest in overseas markets than they have ever done before. An export committee has this year been appointed by the Radio Manufacturers’ Association. This committee is working in close touch with the Department of Overseas Trade and steps have been taken to obtain the fullest information concerning conditions ia the various markets throughout the world which are likely to present an opportunity for the s. te of sets and component parts of Unitea Kingdom manufacture. Careful study is being and will continue to be given to these reports and definite and progressive increase in Unite¢C Kingdom overseas radio trade should result.