THE WIRELESS WORLD

Grey River Argus, 5 March 1937, Page 11

THE WIRELESS WORLD

NOTES FOR RADIO AMATEURS.

(By

“Cat’s Whisker”)

CORRECT PRONUNCIATION DESIRE OF 8.8. C. The 8.8. C. is always grateful for reLabe information on the correct, pronunciation of proper names. Professor A. Lloyd James, the secretary oi the 8.8. C. Advisory Committee on Spoken English, recently made an appeal to listeners for help, which applies also to those resident in the Em. pire. “There are hundreds of family names, surnames, and, indeed, Christian names that are not easy to pronounce at sight. Marjoribanks we know, but there are hosts of others, if not s 0 outrageously unlike their spelling, at any rate quite bad enough to make announcers tremble when they have to be read aloud. If you know a name, your own name, or anybody Oise’s that is often mispronounced, send it on a post card with the correct pronunciation indicated as accurately as you can possibly show it.” Many Empire place names appear in the news- bulletin or the programmes, and listeners can render service by writing to the 8.8. C. when they hear a name- pronounced which is not in accordance with authoritative local usage. This applies equally to names of persons and places. * * * » ♦ « m School Brcudcasts: The 8.8. C. school broadcasting term which closed at Christmas was the most successful yet neld. The number of schools taking part in Eng. land and Wales was over 5 000, and in Scotland 750. A gratifying feature was the enthusiasm of the scholars and their eagerness to test statements made by the broadcasters. Mr. C. Cl Gaddum’s Nature 'talks were particularly" successful in evoking response from the children. He mentioned that ink could be made from toadstools, and was delighted to receive hundreds of letters, written in a brownish fluid made from toadstools. Other children, hearing about migrating storks, wrote reporting that they had seen sura, storks.in their flight across England. One told of a discerning lit that could take the top off a milk bottle and drink the cream, but it would not touch a bottle, of milk without cream at the top. Some young correspondents wished to know why tomatoes turn red, why- mistletoe ber. rics arc poisonous to children and not to birds, and why eels cross the At. lantic. to 'the Sargasso Sea to breed and (die, but never seem to travel from the Sargasso to England. Blind Landings: The Air Ministry investigations into the various “blind” landing systems for aircraft have now reached the stage of practical tests, and three different systems have been installed a! Croydon Aerodrome. In broad outline the working of these “blind” landing systems is as follows; There are three different beams; the first, a horizontal one, gives a well-defined path of approach to the aerodrome from a distance of 10 to 15 miles. For this a wave-length of nine metres is used. The second beam is a vertical fan-shaped one situated between 11 and 2 miles from the aerodrome. Having passed this the aircraft continues to fly along the horizontal beam, until, at a distance of about 300 yards from the landing ground a second vertical beam is passed. These vertical beams both operate on a wave-length o f 7.8!) metres. The systems being tested are suitable for conditions in which the visibility' is so poor that the ground cannot be seen at a height of 50ft. It is hoped that further developments will enable these systems to be employed under the very worst conditions.

Europe’s Voice: Northern Europe is soon likely to make it s voice heard in the work! to a far greater extent than at. present owing to the rapid extension of the SW broadcasting services which is taking place there. Work has been started on a 100-k.w. station near the Icelandic, capital, while. Fillland has

a new 20-kilowatt.station in course of construction. Several stations of . power ratings from 10 to 20 kilowatts are planned for Scandinavia. The Swedish Government ha s granted a million kroner towards the cost of erecting new stations at Lulea, Karlskrona, and Helsingborg. Wired Wireless: Experiments have been tried by the post office authorities at Karlshamn, in Sweden, with a view to radiating broadcast programmes over a telephone line simultaneously with three ordinary conversations. Very success, ful results have been obtained so far, and post office engineers from the neighbouring country of Norway have vis.ted Karlshamn t 0 study the system. It is quite likely that wired broadcasting may eventually play an important part in Scandinavian broadcasting, more especially in Norway owing to the d.faculties of reception idue to the mountainous nature of the country. New Zealand Artists: New Zealand artists to broadcast in the Empire programmes from D'aventry in recent weeks were: —Vera Moore (pianist). Marie Ney (actress), Eileen Driscoll soprano), Arthur Alexander (pianist). ****** Horowitz’s Visit Postponed: The Australian Broadcasting Commission announce, sthat Vladimir Horowitz, tile brilliant young Russian pianist, who was to have visited Aus. Itralia next May, anid: perhaps New Zealand after his Commonwealth tour, will not now arrive until next year. Horowitz is about the most interesting pianist alive- from a fashionable point of view, and his visit in a years time will naturally be looked forward to with interest. ****** Crystal Performance: It. was stated recently that Australian crystal set owners were claiming reception of interstate stat.ons, some of which were many hundreds of miles distant. One Queenslander avered that he had a log of fifteen stations, including South Australians anidi Victorians, but the score was topped by a crystal owner who announced that he was picking up American and European short-wavers on the broadcast band. This caused an expert to inves. tigate. It wa« found that the crystal

was actually reproducing shortwave signals, but only by re-radiation -of a powerful dual-waver next door. This may point to a solution of some New Zealand mysteries. ...... Ultra-High Frequencies: In the early stages of ultra-high fre. queney work if was generally assumed that these ultra-short waves, by which •is meant radiations of the order of five metres, would have a range which was restricted to the direct line between the transmitting and receiving points. For this reason such wavelengths have been referred' to as quasioptical waves, because their assumed behaviour resembled that of light. The only way of extending the range of communication appeared :to be to place the ft/ransmiltting or receiving equipment or both as high above the earth’s surface as possible. The ' approximate range in miles of an elevated transmitter may" be determined by adding half the height, in feet to the height and taking the square root of the result. For example, equipment 96 feet above the ground' would theoretically cover an area of 12 miles radius, half the height (48) plus the height (96) giving 144, the square root, of which is 12. If the'receiving point, is elevated the effective range is increased by' the amount due to such elevation. Thus two points 96ft and 150 ft above ground level could theoretically be spaced 27 miles apart. It was not long after serious experimenting had commenced’ with the ultra-high frequencies that it was found that bending of the waves occurred which resulted in dis. tance in excess of the theoretical be. ing covered. In recent times, as 'the use of 'these frequencies has increased, considerable ranges have been reported. German television transmissions have been received regularly in England, and .the same signals have, on occasions, been reported from New York and Buenos Aires. Reliable communi. cation ha, s been established for a distance of nearly 100 miles from Harvard University’ in the United States, and messages have also been exchanged between New York and Chicago. In England amateur experimenters have covered distances from 100 to 200 miles. In all cases quoted the ranges are much greater than the theoretical max.mum. It thus seems that, at any rate in. suitable circumstances, ultrahigh frequencies can be employed for relatively long distances. Whether this is a useful quality the future will determine. It may be that tor certain types of commercial service additional channels of this nature will be an advantage. On the other hand, these properties of ultra-high 1 frequency' radiations may prove to be exceedingly troublesome. For various reasons wavelengths of this order have been and will be used' for television transmissions. ’Their assumed' limitations of range, in one respect, are a hindrance because, to cover a large area a multiplicity of stations will be required. On the other hand, this limitation has had apparent advantage, that signals from a station would not be heard out of sight of the station, so 'that, the same wavelength might have been used by a number of stations provided that they were sufficiently well separated. Now it appears that sometime, if not always, there is a danger of interference at any distance. At this stage it is not possible to estimate with accuracy the probable extent of such interference, because sufficient work has not. y et been done, or. if it has, the results have not been made known. Observations already made indicate that lor distances of about 100 miles atmos. pheric eondiillons have an important influence. A change in the relative positions of layers of cool and warm air seem to be the cause; of distant reception. The- best conditions ar© a warm layer on top of a cool layer. Investigation on this aspect has progressed to a- considerable' extent, but what is responsible -for reception over distances of 1000 miles or more has not been determined. It has been suggested that there is a suitable reflecting* layer above the layers which are held responsible for the behaviour of short, and. medium waves, and that long' distance reception on this account would lie much more common if there were more listening posts. Another suggestion" is that a- flumber of Javers some hundreds of miles above 1 the 'earth are the causes, the layers acting collectively by' means of reflection and refraction, t 0 produce the observed results. So far it appears that signals can only' be heard over long distances when rare atmospheric conditions exist. * Interference from Motor Cars: Denying a report that the 8.8. C. was engaged' in research in motor car radio, the corporation stated that its interest lay' in the interference with broadcasting caused by the ignition systems of motor cars, and that the experiments bong made were in the direction of devising means to elinr.nate* this interference. The paiticulai type of interference had: not affected broadcasting of sound, except on short 1 waves, but it was expected to prove a menace' to television. In the course of its experiments in the latter art the 8'.8.C. is introducing a van carrying television cameras. By this means it will be possible to .televise events outside the present range of Alexandra Palace. The corporation advnses that “if the present rate of progress is maintained the televising of certain great spectacular events of 1937 should become a certainty.” This seems to be a reference to the probability of .televising the coronation. Jottings: One Auckland radio manufacturing firm released its first, model of the 1937 line of receivers. This set prov. cd to be all that was hoped for it, and already orders are pouring in. It is a fivp-valve, idual-wave recetvcr, and at a most attractive price too — £l9 19s. « ♦ « * * • Empire listeners have cause for regret that Mr. Cecil Madden’s efforts are now absorbed by' television. Incidentally, Eke most, of the 8.8. C. television staff at Alexandra palace, he is working like the proverbial nigger. ' There is no doubt that one of the first p 8.8. C. developments in the New Year - will be to double the staff at the I Alexandra Palace 1 . There is talk of • increasing television hours, but. the - present producing staff of seven have t the greatest difficulty in coping with ; two hours a day'. Half the programmes - are under-rehearsed. t * * •» * • * Right up to the minute is Ida Davis, II R.C.M., New Zealand pianist at. pre-

sent in London. She has recently taken part in two television programmes, being probably the first New Zealander t 0 contribute to this newest of all arts. Miss Dayis, .who returns to the Dominion shortly, has also given a number of recitals at the London Ballet Club (no mean achievement for an “un-influential” colonial, a s she describes herself!).

In spite of the fact that very few areas in North Auckland province have yet been supplied with electric power, a radio boom is raging in the Far North. One Auckland firm alone at present have three representatives busily engaged in working the Kai. kohe. Dargaville and Kaitaia districts. In-fact, business is so brisk that this firm recently opened a branch office at Kaikohe to cope with the work. New sets are much in demand, the latest model battery operated receivers be ing very popular with the settlers.