Notes and Comments

Radio Record, Volume III, Issue 17, 8 November 1929, Page 13

Notes and Comments

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SWITCH

ROADCASTING again "scored a. good win" the other night when 2YA, Wellington, broadcast an announcement that a little girl, six years of age, was missing from her home in a Wellington. suburb. It appears that the child did not come honie when she left the kindergarten at 3 p.m. In the evening the assistance of 2YA was invoked, and within an hour the child was safe at home again, The youngster was at the home of some other children listening in. .When the announcement was made from 2¥A, the kiddie was hastened off to her home, A FRIEND who proposes to go camping during the Christmas holidays, informs "Switch" that his fourvalve portable set is to go with him. Hg has already tested the set in the ‘ri-clad district in the vicinity of Packakariki, and 2YA, Wellington, came in with full loudspeaker volume, although he was using only a makeshift aerial, He will be accompanied by two comrades, and they are looking forward to pleasant hours in the evening listening to 2YA. "THE vagaries of reception from long distances lately has perturbed not a. few listeners, judging by the comments one hears every day. At this period of the year the. "outside" stations are frequently unsatisfactory. The protracted daylight effect with the lengthening-days, and the extra _ half-hour due to New Zealand "summer time’ combine to weaken distant reception until a late hour inthe evening. Some listeners are blaming their valves or their batteries, but in the majority of cases it will be found that the above reasons are the cause of weaker long-distance reception. SET which persisted in raising a *% dismal howl was brought under the ‘writer’s notice recently. The owner found that by placing his loudspeaker outside the room in which the set was located the howl was eliminated. The cause of the howl was shown to be inter-action between the loudspeaker and a yery sensitive detector valve. The reason‘was that the sound waves from the loudspeaker impinged on the glass bulb of the detector valve, causing the valve elements to vibrate, A cure was effected by slipping over the valve a small section of the inner tube of a bicycle tire. The rubber "glove" prevented the valve bulb from vibratjag. " A TWISTHD flex wire such as is used for an electric light extension was recently proved to be the cause of a howl from the loudspeaker of a Wellington listener, He used a long twisted flex wire to run his loudspeaker out on the lawn. A dismal howl resulted, A cure was effected by soldering a ,005 mfd, fixed condenser ‘across the flex close up to the set, The best plan is to use the proper loudspeaker cord, which can be procured up to fifty feet in length. The writer occasionally employs one of these long cords, and has not experienced any howling. i YVicTORIA claims to have more licensed broadcast listeners per 100 of its population than any other eountry in the world. The quota per 100 of population is 7.98. This Australian State established a first-class broadcast service long before New Zealand, but the Dominion is steadily in-

creasing its quota, while Victoria has lately experienced a decrease in the number of listeners, Various explanations for the falling-off have been urged and the economical position of the State is generally blamed for the setback. Sothe writers ‘contend that "saturation point" has been reached in Victoria, while others state that a return of prosperity would-cause an increase in the number of licenses, A SUBURBAN listener has told the writer that he uses two separate detector valves with his a.c, set on different occasions, One valve gives a better quality of tone on local reception while the other is more sensitive for long-distance reception. The valves are of different makes, and have been in use about the same length of time. Their listed characteristics are the same, but they differ in performance. The valve, which gives easily the better results on long-distance reception, has a harsh tone when tunéd in to the local station. ‘ A CUBA STREET (Wellington) jeweller informed "Switch" the other day that his wife had built a suceessful two-valve set with which they obtain at Lower Hutt good loudspeaker reception of 2YA, Wellington. He admitted that he knew nothing about wireless, but his wife became interested in it, and, buying the necessary parts, she soon built a set. A WILLIS STREET (Wellington) radio trader showed the writer a three-vyalve short-wave set sent to him by a home-constructor with a request that it be rebuilt. All the parts were high-grade excepting the transformers, which were extremely tawdry. Amateur builders sometimes do not realise that good transformers are absolutely essential if the best results are desired. The transformers veferred to were about the cheapest articles the writer has seen in radio. E{\NGLISH magazines refer to the appearance of a new screen-grid valve which is claimed to eclipse all valyes of this type yet brought out. . One cannot pass. judgment without kngwing more about the newcomer. We have become accustomed to hearing of new wonders in radio, and some: times their reputation is unjustified, ]{XPERIMENTS in the interchange of radio programmes between the United States and Germany are now in progress. A delegation of four German radio officials went to New York, and arranged with the U.S.A. National Broadeasting Company for the tests, The German delegation manifested

chief interest in the programmes of a typically American nature. They were fascinated with the negro spiritual songs. A WBRLLINGTON listener complained to the writer last week that although he had built an‘ exponential horn loudspeaker out of the best material and with accurate observance of the measurements contained in a magazine article, the horn had proved a "dud." The horn was subjected to a close scrutiny by "Switch," and it was found that the most important feature had been overlooked-the horn was not air-tight. However, this mistake was soon rectified by the use of strong gumpaper, which was subsequently varnished, and the exponential then performed splendidly. HB use of long leads to the C battery should be rigidly avoided in a short-wave set. "Switch" was recently. shown an amateur-built short-

wave set, which persisted in emitting annoying "fringe howls." The leads to the © battery were about 18 inches in length. When the © battery was inserted inside the set so that the leads to it were only about 5 inches in length, the howls disappeared. What amateurs regard as insignificant trifles too often spoil an otherwise good job. A WELLINGTON professional setbuilder informs "Switch" that many of the amateur-built sets sent to him to examine owing to their failure, have been wrongly wired in only one detail. This, of course, is fatal, but the strangest part of his experiences is that the owners state that they have checked the circuit many times, and have found it O.K, The trouble seems to be in the diagrams which figure in many of the imported radio magazines. Sometimes they are wrong\in one small particular, and frequently they are not explicit enough, " MANY Wellington sports were greatly interested in the result of the boxing contest between Ted Morgan (Olympic amateur champion) and Trowern held at Greymouth on a recent Saturday night, Owing to the closing of the telegraph offices at 9 p.m, ‘on Saturdays, little hope: was entertained of getting the result of the contest, At a late hour, however, 2YA, Wellington, supplied the restlt. The information was telephoned through to 2YA from Greymouth, and Morgan’s father, who resides in Wellington, received the news in this manner, We.have.a good sporting news service from 2YA,