TECHNICAL PROGRESS OF RADIO.

Radio Record, Volume IV, Issue 38, 3 April 1931, Page 4

TECHNICAL PROGRESS OF RADIO.

WITH the publication of the "Radio Guide," which marks the opening of another radio "season," we naturally look back over the twelve months that have elapsed since our last Guide came out and point out the salient features of radio progress. We said that we were on the threshold of a "radio season." That term, though serving our purpose as a definition, is not quite correct, for one thing the radio designer has accomplished is a reduction of the marked difference that once existed between the "seasons." Radio now is almost as popular during the summer as it is in the winter, and this is due mainly to the introduction of the powerful sets we have to-day. Twelve months ago, the a.c. screen grid receiver had just made its appearance in this country. To-day it is established, and the number of receivers coming into the country otherwise equipped are very strall indeed. The audio side, too, has been improved, and in many ses the unsatisfactory audio stages have been eliminated. The receiver to-day is as sensitive as atmospheric conditions will allow. Were it any more powerful, the noise level would be increased to a degree that would render listening impossible. This point is an important one, and to some. extent has been responsible for the reduction of the number of stages in many of the sets. There were far more electric four valve sets sold last year than there were the year before. This brings us to another important development, the midget receiver. It has been popular and to all appearances it will be increasingly so next year, for already midgets with gramophone combinations are available. This reduction of the size of the set is almost imiversal. Taken all round, the aim of manufacturers is to eliminate a large percentage of the waste space in the console receivers, for "compactness and efficiency" has been the slogan of the makers of modern sets. Another interesting development has been the extension -of the set’s functions. Last year it was very successfully combined with ‘the gramophone, and this example has been followed up with ‘the introduction of apparatus for home recording and the recording

a 3 of items broadcast. Though somewhat of a novelty at present, therd is no doubt that this‘ additional feature will. be one of those to make) the 1931 set distinctive. The superheterodyne receiver has reappeared with the releasing | ‘of certain patents held by an American corporation. Most manufacturers considered the decision to make the patents available came too late in the season to take advantage of, but with the factories now working at their maximum it is likely that the superheterodyne will be manufactured by a large number of firms. Television seems as far removed as ever. Although interesting demonstrations have been given none were sufficiently convincing to entice manufacturers to begin the production of receivers. The transmission of still pictures, however, is quite an accomplished fact, and trdns-oceanic picture services are now in great demand. A more important link between countries is the radio telephone service, which has this year been widely extended. At this stage most important countrie are connected up. ‘ Short-wave transmission and reception has come-much more to the fore. Far more general listeners are being attracted to this department of radio, and manufacturers are giving them consideration in producing electric combination receivers for long and‘ short way. It is a wise move, for even at present there is real entertainment value to be had through listening to these transmissions. The superior carrying power of these frequencies has alluring possibilities, and it appears that during the forthcoming year many transmitting stations will send out. regular programmes on these bands. Radio is fast settling. We need not worry about revolutionary inventions, for with the high standard now reached it appears ag though attention will be directed to cabinet design, the addition of the gramophone, short-wave adapter, tone centrol, remote control and a host of other refinements. LM HTTHTTOHITTTT@TETTT lS THT beri iiiiiiieliiiuiiie