The Future of Radio

Radio Record, Volume III, Issue 7, 30 August 1929, Unnumbered Page

The Future of Radio

SCIENCE that" is growing side by side with radio is that. of picture transmis‘sion, including radiovision, radio drama and radio "movies." The principle of picture tranemisysion has come to perfection more. rapidly than, .that of | radiovision and its .associated arts. Already, picture trankmission has become commercialised, and the British Broadcasting Company radiates pictures vecularly onthe Fultograph MMMM

system. The principle of © ee . : this apparatus is’ analogous to that of the of pictures for Press purposes. The photograph is transferred on to a sheet of zinc and copper suitably: coated. This becomes soluble when exposed to light, and when washed, the portion not exposed to the light disappears, leaving an insoluble image. Current is transmitted when a.--stylus touches the metal,.and variations in current occur. _A reversal of the system at the receiving end allows images to ‘be received on much the same principle. . In 1928 pictures were tegularly radiated from 5XX,- Daventry, .. England, and about the ‘same time regular transmission across the Atlantic was established... Facsimiles of cheques, photographs, documents, etc., are now regularly sent from Europe to America. PTE principle of radiovision, usually known as television, is altogether i. different. By television is meant the transmission of moving pic- " psgits,: not necessarily over the air. ‘They: may be transmitted through graph line, but ‘‘radioyision’’. involves the use of the ether. The sum ."2e of radiovision to-day is the position similar to that occupied by radio in 1900... = -¢ . Radiovision aims. not’ at transmitting: still pictures, but ‘moving ©. images of the objects televised and the system employed is somewhat similar to that. used in’ the ordinary kinematograph. An image ‘is produced on the screen -in-virtue of the fact that it is.divided up into a large number of. images each of which. may be considered .a. stil] . picture. Owing to the rapidity of these, the eye translates the move‘ment. To attain this, each image’ must rest on the screen no longer than 1/15th of a second. In order to obtain this breaking-up of the original object, what is technically. known as a "scanning disc’ is brought into ° operation. This is a circular dise in which are a large number of | small apertures, usually 48. Behind this is a photo-electric cell and the scanning disc moves in front of the cell so that each small still "picture is registered on it. . ‘ wt The construction’ of a photo-electric cel] is such that variation in the intensity of light is translated as variation in electric current. This MM HARCURERCERA TAAL EECGERELED ALCP TOUTDRE APES ERE LUMI

is amplified and put on the air in much the samé way as a broadcast station. With radiovisiowy there .are certain very baffling obstacles. To obtain a sensible degree of light on the photo-electric cell, tremendous candle power ‘must be thrown upon the object to be televised, though we read in a recent public tion that objects have been televised in the open air. The size of the picture so obtained rarely exceeds two inches.square. To reproduce the. movement at the receiver end; a disc of 36in. diameter = -_ = = = -_ = = = = =

has to be used. The vibrations are collected from the ether and amplified in an‘ ordinary receiver. This ampliffed current is passed through a neon cell which translates the electric vibrations in varying intensities of light. To receive an image a scanning disc must move in front of this cell. In dimensions this must be the same ass those of the disc at t= transmitting,end. In addition, its movement must perfectly synchronise: with _that at the other end. Not only must the two moye at the same pace, but they must each occupy the same position at the same time. , ‘Working under this system, radiovision is, beset with obstacles, and Hugo Gernsback, until recently Editor. of several of the leading | American technical publications, has stated that in his opinion an entirely new system is necessary. , , a Two American experimenters well known. to the radio world, De Forrest and Jenkins, are working upon new systems. The Jenkins system employs a very large number of photo-electric cells arranged on a screen, '. while the De Forrest system is such that the image remains a tenth of a’ second after the scanning disc has moved on.’ These new developments seem certainly to be more hopeful, but radiovision, as apart from picture transmission, has not yet passed the experimental. stage. wo The Advent of Radiodrama. i . N September 1, 1928, the first. radiodrama was broadcast. ‘The radiodrama is a combination of radio and radiovision, and its possibilities in the future seem unlimited. It has been ‘stated that it will almost entirely replace the stage. That it will, to a certain extent, is quite evident, the substitution, no‘doubt, following closely that of the substitution of radio talkies for orchestras. * ° Another development is multiple radiovision, by which several screens each viewing the object or objects from different angles can be operated at the same time. It will be possible under this system to see and hear, say, a boxing match in one: country, a band contest ‘in another, and an aeroplane landing in another. The use of this system in a future way can likewise be visualised. . , -Continued on page 2. MIMIMN MUDGEE il

With radio is wrapped up the allied sciences of radiovision | and picture transmission. The future of these sister sciences | will: mould the whole communication systems, giving it an. aspect yet undreamed of. The wireless set-that noisy, untidy . collection of unsightly apparatus in the corner of an obscure room-has disappeared; it has been replaced by a musical instrument to which will some day be added an optical instru-ment--but the advent of this is not just round the corner. The accompanying are the remarks ‘of our technical editor, to the Wellington Radio Society.

. Future of Radio _ ‘(Continued from -front page.) Further Developments. ON October 20, 1915, for the first time in history, a man in America telephoned to another in the Hiffel Tower in Paris. From then onwards, the radio telephone has been perfected with almost startling rapidity ; 1927 saw the institution of a regular service between America and Bngland, and this has been now extended and Sydney has spoken to London. In other pages of this issue we read of the conversation between a boy at death’s door and his mother in London. Radio is being applied to almost undreamed-of developments, and it is not an exaggeration to say that the commercial life of to-day would be impossible without radi in any of its allied forms. Two problems have confronted radio throughout its whole history-static and fading. They are‘the same to-day

as they were. when .the first message was transmitted 30 years ago. Static eliminators have been devised, but none have been entirely successful. Wonderful stories have been built around some of these instruments, but in common all have reduced the strength of the signals as well as the static. Underground antenna, loop antenna, patent antenna have all shown that .they were more or less insufficient to cope with the problem. In saying that statie will in all probability never be eliminated Hdison has come somewhat near the truth-but. it will be overcome. When wireless first came into being tremendous power was necessary at the transmitting end. With the advent of the valve it was found possible to reduce the power of the input very’ considerably, yet output was strengthened, These transmitting valves are being impreved very rapidly, they: are ‘peeoming smaller in dimensions and more powerful. In support of this Mr. Smith handed around a transmitting valve of large dimensions, remarknerd

ing that this was capable of delivering an output of about 500 watts. Against this the modern water-cooled valve of the-same dimensions is capable of an output of 5000 watts, and even more, and this marks the progress of only ten years. Static is not noticed on the local sta~ tion because of the strength of its output, With the increasing strength of the stations it will some day be possible. to receive these at the same strength as the local, and then, and not till then, will static be overcome. Fading is a different problem. Its exact significance is not properly un-, derstood, though the Heaviside layer theory seems very feasible. Fading is receiving a great. amount of attention at the present. Among other things, the Byrd expedition is investigating this phenomenon, and it is possible that this will also be overcome. Again, the increasing power of the stations will bear forcibly on this. Radio of the Future. With the rapid development of this science, the future indeed is very promising.. As far as the receiver is concerned, it will no doubt remain all electric until something more powerful than this is discovered. Perhaps it will be rendered obsolete with, say, the harnessing of the disintegrating atom. Each season has seen fresh developments in the receiver, though none revolutionary. The triode, the fourelectrode, the pentode, the sereen-grid, the A.C, triode, the A.C, four electrode, have each in turn found their way into our receivers without rendering them out of date. ‘To-day the fashion is the A.C. valve; next season will see the introduction of the A.O, screen grid, a valve with a possible amplifica‘tion factor of 300. And this valve can be easily fitted to any existing receiver. The set of the future is not difficult to picture. One valve, combining tone quality and power, one eontrol, and within the reach of every one, Yet-this is future, only yet in the "imagination stage."

The possibilities of radio vision-see-ing, talking to one’s friends thousands of miles away will be. commonplace. With the development of radio and aviation, space and time are being annihilated. Individual movement is being reduced to a minimum. What of war? The horrors of the last war, when radio and aviation were in their infancy, were beyond description. Imagine a calamity with. these sciences developed to present-day standards and, more important, the possibility of their development jn the case of need. Wireless will render war impossible, impossible because of its terrorism. . The possibilities are without bounds, the future is still a closed book to us, and perhaps we should be thankful for this and say with Butler: "You have shown us yesterday, with to-day we Uve, but, please God, keep down the veil that separates us from to-morrow."