THE WIRELESS WORLD.

Otago Witness, Issue 3661, 13 May 1924, Page 8

THE WIRELESS WORLD.

Magna Vox.

NEWS ANI) NOTES.

(By

[ltems of news, comment, suggestions, «tc., will be welcomed by “Magna Vox.”J Messrs L. Shiel and It. Slade were engaged during the Easter holidays in taking tests in several places outside the city. The time at their disposal did not permit of many records being taken, and I understand that in the near future further tests wj.i be taken, and data completed with a view to arriving at the solution of fading signals. A number of reports have come to hand of long-distance reception. The items from KGO, California, are about the best, but static has been very bad lately, and every week howling valves become worse, and there are about 12 very bad offenders in this respect. Apart from this, some very good items have been received. Musical items from 2BL (Sydney) have been coming through very strongly lately, but the voice transmission is very blurred, owing to over-modulation. ’ An Australian amateur of some standing, who recently visited Dunedin, informed me that in listen-ing-in to the stations in that country the items came through "very rough,” and that there was plenty of room for improvement. The Gisborne Broadcasting Company, 2YM, are to be heard w'ith exceptional clearness at present, and there is no doubt that it is the best of the New Zealand stations for long-distance work. The Wellington Broadcasters (Ltd.). 2VB. are also exceptionally clear, and the musical items are of a h.gh standard. A French amateur has just devised a special coating for metal horns. This is claimed to result in a perfectly pure tone, suppressing the difference in phase between the diaphragm and the horn. In a general manner it makes use of a thick varnish made of pulverised resin and cork dust of varj-ing fineness. The inventor claims -**at he suppresses the resonance of the metal composing it, and as a result that the vibrations of the transmitter are heard with their original intensity and tone. This composition has also been tested on a telephone diaphragm with a great improvement in the clearness of the sound. SEEN BY WIRELESS. An American inventor, Mr C. F. Jenkins, recently demonstrated his wireless television system, and the full story of his success is given in the journal “Wireless Review'.” In his laboratory Mr Jenkins had a small kinema screen, and people were able by wireless to see him move his hand about, -the editor, who has taken a keen interest in television, believes that it will not be long before w'e shall be able to see on a small screen in England, at 4 o’clock in the afternoon, what happened in America it 11 o’clock. Some time ago “Wireless Review” started a competition for radio television, and it is interesting to note that the foresight of that paper i s not what some scientists thought to be—a fantastical idea. It has resulted in the fact that ‘‘Wireless Review'” is the first British journal to report and give details of a new television invention in wireless. WIRED WIRELESS BROADCASTING. There was recently given the first demonstration of commercial wired wireless broadcasting, as applied to electric light wires on Sa-tfen Island. New York City. The studio is not unlike the usual radio studio. The output, instead of going to an aerial and ground connection, is delivered to the electric wires passing by the studio. I he wired wireless broadcasting company is planning an 18-hour daily programme. Electric light users can subscribe for the service, in which case they are furnished with a compact receiving set which is attached to any electric light socket or outlet bv means of the conventional plug. The lowest subscription rate provides for a crystal set and head phones, while the highest rate provides for a loud-speaker set. If the Staton Island installation works out successfully, both technically and commercially. the idea will eventually be extended to other electric light systems. 4YA’S NEW PLANT. 4YA station, Dunedin, now has the whole of the plant renewed. Eight valves are expected any day, and the 500-watt new set will then be brought into operation. The whole of this large set has been designed and manufactured in 4YA’s workshop. There will be four amplifying valves and two D.V.2 valves, worked from pushpull transformers. The following stage will be a five-watt, then a 50-watt, and this will pass into the modulating valves. It is the intention of Mr O'Neill to have three modulators of 250 watts each, and three oscillators of 250 watts each. These valves are capable of working 20 per cent over their set wattage. The new generator is capable of giving an output of 1400 watts. This will allow of the station radiating a full 500 watts into the aerial when required. No expense or trouble has been spared in making this Station one of the best south of the Line.

In the near future everything will be in working order. The whole outfit will be worthy of inspection, and shows what can be done in Dunedin by local workmen. MARCONI AND SHORT WAVES. About- a year ago Signor Marconi reported before a joint meeting of radio and electrical engineering societies, at a meeting in New' York City, his interesting and apparently promising experiments in shortwave radio. He showed experimentally bow the short waves could be reflected by an “electrical mirror” and sent in any desired direction, like light waves, and how easily they might be absorbed. There was nothing new in these special experiments Hertz having done exactly similar ones in his laboratory 30 odd years previously, but the experiments aid indicate to the large and enthusiastic audience how Hertz’s laboratory experiments on short waves might be turned to practical use. If radio waves could be confined to one direction, instead of spreading out in all directions, much less power would be required and much interference would surely be eliminated. It appears that he has been applying himself to the problem with very successful results. Although he did not mention short waves as the means he employed, reading between the lines of his interview we are forced to conclude that such was the case. "We have transmitted messages up to a distance of 2500 miles, not only with much smaller power, but also far more cheaply than with the ordinary system of long-dis-tance wireless,” he said. “To send the message 2500 miles took less power than the ordinary message from London to Paris.” WELLINGTON RADIO SOCITEY. Another meeting to deal with the inauguration of a Wellington Radio Society was held last week, and matters were so far advanced that a general meeting for the definite formation of the society is to be held shortly. At that meeting a draft constitution, based upon the rules of similar bodies, will be presented. It is proposed to call the organisation the. Amateur Radio Society of Wellington. Its objects are thus set out: — 1. The furtherance of all matters and studies connected with amateur wireless telegraphy and telephony. 2. The promotion of intercourse and ideas between all classes of amateur wireless experimenters and listeners-in. 3. The encouragement of “radio-oz-der” amongst listeners-in by means of technical advice and help. 4. The encouragement of beginners in amateur radio. 5. To encourage the affiliation of other bodies which shall subscribe to the rules of the society. b. To supply representatives of listeners-in on the Dominion Broadcast Control Boai'd. It is proposed to classify members, as seniors, 18 years of age or over, and juniors, below that age. The juniors will have all the privileges but that of Voting, but may elect a representative who shall vote at committee meetings. Country members resident more than 25 miles from the G.P.0., Wellington, will be similarly divided into senior and juniors. Election of membership is to be by ballot; a.nd candidates must hold a Government license. The proposed subscriptions are : Senior members, £1 Is; senior country members, 10s 6d; all junior members, 5s per annum. The meeting requested the acting honorary secretary, Mr Chatfield, to obtain the frill text of the agreement reported to have been arrived at between the representatives of the Post and Telegrarjh Department and the N(ew Zealand Broadcast Committee regarding the proposed broadcasting scheme. WORLD-WIDE BROADCASTING A new system of btoadcasting, introduced by the Westinghouse Company of America, is said to be the most important step since broadcasting itself was initiated. The system makes it possible for a speech or concert delivered at a central point to be received clearly by radio listeners with even the cheapest instruments over great distances. This is done by sending out the original broadcasting on a very low wave-length with peculiar penetrating quality not possessed by the high wave-lengths usually employed for broadcasting. The low wavelength broadcasting cannot be heard by the ordinary receiver, but it can be picked up bv special apparatus at the various stations and repeated to local listeners on the ordinary wave-lengths. It is thus possible for small local stations to obtain regularly material of the highest quality. The uses of such a system are obvious. In an editorial headed, “The Whole World as Radio Audience,” the Post (Pittsburg, U.S. A.) says of it: “Radio service in the past few years has gone so far beyond the eai'ly foi'ecasts of it that when we are informed now of a system or relaying broadcasts by which the peoples of the United States and neighbouring countries may be treated as one audience, we may easily believe the prophecy that it will not be long until there will be a world crier as there used to be a town beadle. “Now the Westinghouse Company has perfected a system by whioh great musical or other programmes may be heard simultaneously by the people of the two Americas and their neighbours. By the new arrangement tue highest talent may be obtained for each evening’s entertainment.

This great system is started by the establishment of a relaying station at Hastings (Nebraska), the first of its kind in the world. Broadcasts will be picked r.p as easily and with the same apparatus in the far Western States as they are now in the Pittsburgh district. 1 “What this will mean to the Government. to education, to business and to the candidates in National campaigns is beyond estimate. It should be of the utmost aid in relieving our Presidents of the hardships in speaking tours. The President can speak into a microphone in Washington and be heard distinctly throughout this country and its neighbours—by an audience estimated up to 200,000,000. In time, it is predicted, lie will be able to speak in ibis wav .o the entire world —not in any instance through an announcer, but by bis own voice wholly. On Sundays the people everywhere may hear the greatest preachers. “With such a marvellous device to serve it, civilisation ought to progi-ess as never before, with the world made more interesting as well as wiser.”