THE WIRELESS WORLD

Otago Daily Times, Issue 22295, 22 June 1934, Page 4

THE WIRELESS WORLD

NEWS AND NOTES By Magna Vox. Items- of local interest are invited by "Magna Vox" for publication in this column. It is necessary that such matter should reach this office by Tuesday of each week for insertion. on the following Friday. ■. 2BL, Sydney.—Bss K.C., 853 metres. 2KC, Sydney.—66s K.C., 322 metres. 3AR, Melbourne.—62o K.C., 492 . wetreb 3LO. Melbourne.—B3o Ki'C.'i 371 metres. SCJL,, Adelaide. —730 K. 0., 395 metres. 4QG, Brisbane.—76o K.C.. 385 metres. IYA, Auckland.—6so K.C.. 461.3 metres. 2YA, Wellington.—s7o K.C., 526 metres. 3YA, Christchurch.—72o K.C., 416.4 metres. 4YA Dunedin.—79o K.C.. 379.5 metres. . 4YO. Dunedin.—ll4o K.C., 261 metres.

ANSWERS TO CORESPONDENTS "R. D. F.," Dunedin.—ln ordinary methods of amplification the current drain, and therefore the voltage at the smoothing circuits, is substantially constant. In this system, when there are no signals there is' little current drawn, and as signals increase, so does the current unless special precautions are taken to prevent excessive voltage drop in the rectifier, etc., when the consequent variations are likely to upset the voltages applied to all values and hence the operation of the set. "Aerial," Anderson's Bay.-—(1) You should have the aerial at least six feet above the iron' roof, ■> but the farther away you can keep it, the better. (2) The single wire, 60ft long, would be the better collector. (3) Either 3/20 or 7/20 bare copper wire- is, in my opinion, the best for an aerial.. "Magnet,'' Mataura.—lf you replace the speaker field S-P. with a resistor of 5500 ohms at 50 ni.a. you could employ a magnetic speaker. The output will, however, be too great for the average magnetic speaker, and will result in distortion due to overload if the amplifier is turned up. The 2A3 may be replaced by a 245 without alterations. THE CONTROVERSY PROBLEM. Regarding the efforts now being* made to ' remove the controversy ban in New Zealand, it is interesting to observe that the 8.8. C. (England) has now considerably widened the scope of the controversialist -at the microphone. Two oi three years ago there would have been an'outcry at the news that a Spiritualist, a Theosophist, a Unitarian and a Rationalist were each to explain their points of view in a broadcast talk. The series in which they appeared was entitled " What I Believe." An " inquiring layman " questioned the speakers and summed up his conclusions. BIGGER STATION FOR DUNEDIN. It is understood that work is progressing, according to plan on the transmitter and studio sites at Auckland. If progress continues in the future as it has in the past, there is every reason to anticipate that the new station will be in operation well before the year is out. In fact, the testing. period of the new station- may come on listeners by surprise. While on the subject of new stations, it is stated that the engineers of the Radio Broadcasting Board are at present engaged on making a series of testa in the vicinity of Dunedin to determine a site for a new transmitter. When a suitable site has been found it is understood that work will commence of giving Dunedin a new and up-to-date station of considerably greater power than the presentone. 'Judging by past experience at Christchurch and elsewhere, Dunedin should have its new-station toward the middle of next year, orJpossibly a little later. When that work is completed the city of Wellington will-be the. only main centre without a new station.. .It is understood that this will be attended to when the tims" comes.

THE TEST BROADCAST. "Australia won by nine minutes." This was in effect . the announcement which sent, thousands in New .Zealand seeking.a few short hours of sleep about 5 a.m. on Wednesday, at of a broadcast that for sustained interest has no in southern lands. : It was an achievement of which the. Australian Broadcasting Commission may be justly proud, and for which New Zealanders should be exceedingly grateful. How it was all done, a subject of much argument, has previously been explained. Just what it has done for broadcasting is only now being realised.' It is quite safe 'to say that as a result of this Australian. service New Zealanders, as a whole, have been made more cricketminded than through any actual touring team- that hasC ever visited these islands (comments a. writer in a northern, paper). Judging ,by : comment one hears-from so many quarters, a remarkable number who have never watched big cricket. before, saw a Test Vame vividly.played. "Saw " •is really the correct word• to use, for so vivid'wa s ..the description that anyone of average; intelligence could visualise the whole scene. The word pictures, too, were so well painted in their ; detail- that - thousands must now know more-of the finer points of the game than they would learn as mere spectators without expert guidance.- New Zealand cricket will, undoubtedly feel the needed benefit of increased public interest from this broadcasting service of. her neighbour. It has been quite astonishing during ■ the past few days to hear even women, who previously knew little or nothing of cricket, keenly discussing batting, bowling, and fielding performances with all the confidence and enthusiasm born of experience. The writer has heard many important Australian broadcasts during the past 10 years, but in descriptive effectiveness none has equalled this latest effort of the A.B.C. staff. Even the historic account of 2BL of Kingsford Smith's flight from Suva to Brisbane in his trans-Pacific venture takes second place to this tale of a cricket match so full of dramatic incident.

QUALITY OF REPRODUCTION. Of late manufacturers have given much consideration to the production of sensitive sets, as a result of the demand caused by the misguided ideas of those who consider that a receiver's main.virtue is its ability to pick up large numbers of stations,, forgetful of the facts that fading and other natural phenomena will more often than not spoil the programmes, that there is a sameness about the programmes from the majority of stations, and that only one station can be listened to at one time. This demand has been created in many instances by the methods of some suppliers, who have stressed the fact that their product has received, say, 80 stations, and is, therefore, more desirable than another which can receive only 70 transmitters, and far superior to one with a miserable performance of 15 or 20. The point is never made that in all instances the number of transmissions that can be regularly and enjoyably received are probably equal to numbers in all three instances, and that, in the latter case, the quality of reproduction may be better than in the other two. This, of course, assumes that the types are not widely differing, and that there is no carelessness in design. All this brings one back to the primary question of what is the fundamental purpose of a receiver. There are two ways, of considering the problem. It may be designed for the reception of more or less intelligible signals from far and wide to the detriment of its ability as a reproducer of "high quality music or the object of its designer may be to provide an instrument capable of giving the maximum entertainment and musical quality, consistent with the shortcomings of transmitters and the disturbing effects of natural and man-made interference, without paying' any more attention to sensitivity than is necessary to ensure reception of the required signals. It is unfortunately not easy to combine to the maximum degree in a reasonably simple receiver the three essential features of ability to pick up very weak signals, of keeping out undesired very strong signals, and of providing a hitrh degree of musical perfection. Th« three, or at any rate the first and last, are to an extent opposed and undue prominence in one may detrimentally affect the other. At one time there seemed a chance of competition resulting in the production of large quantities of cheap sets in which musical quality was by no means the first consideration. The danger seems to have passed, but it is one which is never far away. When such n state exists it is an easy matter to blame the manufacturer, often unfairly, fow the state of affairs. He may be partly at

fault, but not entirely, as it is a primary task to supply what is wanted, and if the buyers will accept instruments which are obviously wanting in fidelity of reproduction it is they who must accept the responsibility. The lure of cheapness is one that is difficult to resist, but if the drop in price L achieved by affecting the set's reliability or its fidelity, it should be strenuously avoided. If it is the result nf sound design or research it is, of course, to be encouraged. The time is long past that a receiver need be recognised as such because of its peculiarities or poorness of quality. Neither should it be classed as having a "tone." It should produce its sound naturally, nothing more and nothing less.