OVER the AERIAL

Auckland Star, Volume LXI, Issue 62, 14 March 1930, Page 17

OVER the AERIAL

Irish music will foe featured at IYA to-morrow evening, in anticipation of St. Patrick's Day, *vhich falls when our local station is silent. On Thursday evening next, if conditions are favourable, IYA will rebroadcast the 2YA transmission of the welcome to Lord and Lady Bledisloe. If conditions are not favourable, will the land line be used? Chief among contributors to to-night's programme will be Miss Sarah Stacpoole, whose soprano solos are always welcome. Mrs. J. Le Pettit and Mr. Zante Wood will be heard in humorous duets from IYA on Wednesday night. On Tuesday there will be the usual miscellany of operatic selections, with a talkie relay from the Majestic Theatre. As usual on a Monday evening, the writer tuned in 2YA, and found quite an enjoyable programme marred by an elocutionary effort that must have rasped tie ears of many listeners. It is impossible to imagine a dialogue between Sherlock Holmes and a criminal -whom he had brought to 'book, conducted in such a continuous shout as assailed one on Monday night. The result was an item spoiled by being hopelessly overstrained.

Many listeners sat up till early on Wednesday morning to hear the twoway transmission which brought Admiral Byrd into touch with hi<3 native land. This was the final of many demonstrations associated with the Polar expedition, in which the efficacy of broadcasting has been demonstrated. The simplest part of the transmission lay in New Zealand, where, through co-operation of the-P.-and T. staff and the Broadcasting Company's officiate, Admiral Byrd's speech was wired to Wellington, and thence broadcast to 2ME, Sydney. This was nothing unusual in the way of an achievement, yet the success with which it was accomplished is a tribute to the enterprise of our local service. The most difficult task fell to the lot of 2ME, the A.W.A. short wave station in Sydney, which kept successful touch •with Schenectady. That an Antarctic explorer, landing among one of the most southerly civilisations of the globe, should be able to send his voice over the two great continents of western culture, is another of the many achievements which broadcasting 'has added to its credit. The one drawback in this astounding feat is that New Zealand had to be dependent upon Australia to bring it in touch with the northern hemisphere. Are we the only important British dependency that is without a worldrange broadcasting short-wave plant? If so, national policy in this field has been lacking in foresight. It is really more important that we should have a transmitter capable of conveying the voice of New Zealand to the outside world than that we should possess a broadcasting station allegedly capable of maintaining communication throughout the Dominion in case of disorganisation of the usual channels through industrial upheavals. This, it is understood, was one of the reasons which stepped up the power of 2YA well above that stipulated in the original agreement. The necessity for this emergency means of communication throughout the Dominion has not yet arisen, nor is it likely to arise, but occasions there_ have been where a short-wave transmission audible throughout the world would have been of inestimable value. One case in point might be referred to—the time when the earthquake rocked the West Coast. Many fantastic impressions have been disabused had there existed a broadcasting station which could have kept the world in touch with the true position.

THE MOST DESIRABLE FEATURE. A survey recently made by a prominent radio magazine among 1000 dealers revealed that the public's first demand of a receiver was fine tone quality. Price proved to be the second important factor, with selectivity third. Appearance, reputation and the possession of screen-grid tubes follow in the order named. These findings are very satisfactory to manufacturers who have consistently made tone quality their outstanding ideal, and who have likewise striven to meet public demands on the other items mentioned. Many factors go into the making of fine tone quality. Total shielding, correct by-passing, and the use of R.F. chokes and filters prevent distortion of the broadcast signal in passing through the radio frequency stages. An extended audio system that brings in high and low as well as medium tones is made possible largely bv correctly designed transformers and connecting circuits. Power detection is a recent factor in improved tone quality, giving better results, particularly from modern broadcast stations employing high modulation in their transmission. The new power output tubes, combined with electro-dynamic speakers of high operating efficiency are still other factors of importance permitting undistorted output at high volume levels. Dual type volume control permits operating at any desired signal level within the- operating range of the tubes without affecting the tone quality.

WIRELESS NEWS FROM FAR AND NEAR. (By "PHONOS.")

On Monday, March 17, a lecture on power amplifiers and loud-speakers will be given by Mr. R. E. Grainger at the Leys Institute, Ponsonby. The lecture has been arranged by the Auckland Eadio Society, and all interested are cordially invited to attend.

In its year book for 1930, the 8.8.C. devotes an excellent chapter to "Intelligent Listening," and gives as one of the reasons why broadcasting is not universally cultivated, the fact that many who are able to avail themselves of its services do not use sufficient discrimination in doing so. It is inevitable that every broadcasting programme cannot measure up to indivdual expectations, because one particular taste is not always being catered for. Before we listen to a radio programme, it behoves us to scan its published details, and find out what will appeal. If these are selected, tuned in at the notified times, and then the set is switched off, there would be less dissatisfaction. Of course, some may find it difficult to satisfy individual tastes during one night of Dominion broadcasting. In that case it is better to be unsatisfied than dissatisfied. Actually, if we curtail the hours of listening, we shall not abuse a privilege, and shall find that listening becomes a more satisfying and a more fixed habit.

AUSTRALIAN SERVICES CRITICISED The quality of transmission of Australian broadcasting stations is severely criticised by a iiniversity graduate, who resided for a number of years in England and on the Continent of Europe. Writing to the editor of the "Sydney Morning Herald," he says he was keenly interested in wirele=i, and after building one set and another, scientifically and regradless of expense, he turned his attention to loud speakers, with a view to the perfect quality of reception. Early last year his wireless gear was transported, to Sydney. "Instead of its operation continuing to be a joy," he writes, "it is turned off very soon whenever it is tuned in, the quality of transmission of Australian broadcasting stations being shocking. "It wa3 often possible to criticise the make up of programmes in Europe, but very rarely did the loud speaker produce a caricature of the events taking place at the 'other end.' A jazz band sounded exactly like a jazz band, a male announcer sounded like a human being of one's acquaintance, and a full orchestra retained all the glory of a full orchestra in a concert hall, and did not sound like a brass band playing out of tune. A good loud speaker and a perfect wireless set, should reproduce the sounds of human speech, brass band, organ, soprano singer, or piano, exactly like the real thing. It does not do so here. In fact, the best loud speaker becomes an obnoxious instrument to any trained ear when used in New South Wales. "It is probable that there would have been a storm of criticism of this state of affairs if listeners in Australia had heard good sets elsewhere. Unfortunately, many people have come to think that the nature of the noises emanating from their loud speakers is something inseparable from wireless. "The criticism of the quality of the Sydney reproductions indicates that it is steadily becoming clear to listeners that something is wrung. But just when two or three writers with good sets and some technical knowledge have severely attacked the modulation, in will come a letter from Alice Springs or the Guf of Carpentaria, saying: 'I cannot understand your carping critics of 2FC or 2BL. When I tune in my superneutro-hexo-dyne both these stations come booming in. Let your listeners look to their sets.' This man outback has missed the whole point of the criticisms. Hβ has been delighted, no doubt, to hear a station hundreds of miles-away booming in, as he calls it, whereas previously he was a lonely worker almost out of touch with humanity. He has still to realise that wireless can do more than this. "Our broadcast programmes, too, "will not bear comparison with those of other countries. Let me point out the titter futility of the relaying of musical programmes from Melbourne over a land line of about 600 miles. The 'Tales of Hoffman,' for example, arrived here clearly, but so distorted that any 'bright young thing , hearing it would have said, 'If that is supposed to be good music, for heaven's sake turn on some jazz.' SCREEN-GRID SIMPLICITY. The prospective radio set buyer is besieged on all sides with sales talk praising the new screen-grid sets so that he is familiar enough with the name, but, as a name, it conjures a thousand questions in hie mind. "What," he asks in a very simple and logical manner, "is the actual difference between the screengrid set and any other get? And what will it do that other sets will not? Is it a receiver that needs special operating conditions or a lot of gadgets 1" Letting the prospective buyer know is juct what some well-meaning dealers fail to do; in some casee, fearing that their technical argument may prove baffling to the lay mind and in other cases because they have but the faintest of ideas in their own mind concerning its points of superiority. In simple language, a definition of the screen-grid tubes for the purpose of amplifying signals received from the

broadcast station before they are converted to audible signals by the detector. The screen-grid tube is a comparatively recent development in radio tubes which permits a tremendous increase in amplification over the old tubes. Thio simple statement answers fully the question of the prospect. If he is technically inclined, an explanation to greater length must be employed. For example, in the screen-grid receivers the higher amplification in the r. f. stages makes it possible to include several new operating features in the remainder of the receiver, such as linear power detection, better selectivity, improved radio quality and quieter operation. To answer the prospect's question, "Does it need special operating conditions?" He can be informed negatively. The ecreen-grid set can be operated under exactly the same conditions as any other set, save that the aerial need not be as long, because of the greater sensitivity of the radio-frequency amplifier.

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