History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1951 04

Front Cover

Australian Radio & Electronics

incorporating

Australasian Radio World

Registered at G.P.O., Sydney, for transmission by post as a periodical.

APRIL, 1951 - Vol. 15, No. 9

1/6

P.01 - Contents Banner

AUSTRALIAN RADIO AND ELECTRONICS

and incorporating

AUSTRALASIAN RADIO WORLD

Vol. 15 - APRIL, 1951 - No. 9

P.01 - Contents

CONTENTS

Our Cover . . . . 1

Editorial . . . . 2

The Short Wave Miniature Three (Battery Operated) . . . . 4

A Low-Powered P.A. Amplifier for Accumulator Operation . . . . 9

Vacuum Tube Methods of Measuring Insulation Resistance of Condensers (by the Eng. Dept., Aerovox Corporation) . . . . 13

Novice Set-Building — A Section for the Beginner . . . . 16

R. & E. Television Project for Home Construction (Part 4) . . . . 18

Some Waveforms and How to Make Them . . . . 21

"Ham" Activities . . . . 25

Short Wave Review . . . . 29

Classified Advertisements . . . . 27

Our Cover

Quality control of each individual unit is an essential factor in the production of Loud Speakers. Our Cover shows a reproducer from the production line being checked for frequency response on a Beat Frequency Oscillator and Amplifier in the Rola Test Laboratory. Each Rola speaker is subjected to this final oral test to check cone resonance, self resonance, sensitivity, plus its ability to fully reproduce the audio frequency spectrum .

P.01 - Publication Notes

Subscription Rates: 12 Issues 18/- Post Free

Published by the Proprietors: Radio & Electronics (N.Z.) Ltd. (Publishers - Incorporated in N.Z.) 17 Bond Street, Sydney, N.S.W.

Correspondence: All correspondence, contributions, and enquiries referring to advertising space and rates should be addressed to our Registered Australian Office:

The Editor, "Radio and Electronics", 17 Bond Street, Sydney, N.S.W., Telephones: BU3879, BW7746, Telegrams and Cables: "Cranlay", Sydney

Managing Editor: LAY. W. CRANCH, AMIRE (Aust.), M.W.I.A., VK2XC

Providing National Coverage for the Advancement of Radio and Electronic Knowledge

Sole Wholesale Distributors - Gordon & Gotch (A/asia) Ltd.

Wholly set up and printed in Australia by R. V. Byers, 9 Wetherill St., North Lidcombe. 'Phone: UX6681 (Footnote P.1)

P.02 - Editorial

The Importance of Television

In a recent press interview, Mr. C. O. Stanley, chairman of directors of a large British television manufacturing firm, had some very interesting remarks to make on some of the aspects of television that seem to have escaped consideration here. At the moment, the Government is no doubt deliberating whether, in view of the international situation, it would be wise to expend money and effort in establishing a television service. Except for the fact that the Minister of Broadcasting has expressed himself as being very much in favour of the early introduction of television, other things being equal, nothing is known of the Government's intentions, but it is only natural to assume that the recent rapid deterioration in world relations must have had an effect on whatever views the Government may hold. The question will now be one, not of estimating the desirability or otherwise of our taking a practical interest in the newest and most potent means of home entertainment and education, but of considering whether every effort of which we are capable will not soon be needed for more urgent purposes. In this connection, some of Mr. Stanley’s remarks are worth more than passing consideration by the powers that be. It has been estimated, said Mr. Stanley, that a third world war would require electronic equipment to be manufactured and used on a scale fourteen times greater than during the last war. He did not say by whom this estimate was made, but it is not unreasonable to suppose that a man in Mr. Stanley’s position should be close enough to official quarters for such a statement to have been made with "inside" knowledge. Those of us who had some opportunity to observe the vast use to which electronic equipment was put during the last war will realise just what this statement signifies. Surely even the combined capacity of Britain and America will be hard put to it to produce equipment on such a colossal scale, and if this is so, then not even the relatively smaller manufacturing capacity of Australia and New Zealand will be of negligible importance, In both countries, however, the radio industry is, in the main, concerned with the production of domestic radio receivers, and there is a vast difference between the knowledge and technique required for this job and that needed for making highly specialised war equipment. Considered in this light, television assumes a new importance. It is a fact that only the possession of a flourishing television industry enabled Britain, during the last war, to put radar out of the laboratories and into the field, with a speed great enough to be of practical assistance, first to the defence of the country, and later to the highly successful offensive operations that were made possible only by electronic means. It may not at first be apparent just why the television industry was such a telling factor. There were two main reasons. The techniques which distinguish television engineering from "ordinary" radio work are exactly those which similarly differentiate radar and most other of the war-time electronic developments. Thus, a large section of the British radio industry was able, through its knowledge of television practice, to turn this to immediate practical account in switching over to radar manufacturing. It was even possible, by a lucky chance (aided by some thoughtful planning) to make direct use of a large amount of equipment that had actually been designed for TV receivers, thereby short-circuiting a great deal of development time on one particularly important project. We do not suggest that the same thing can happen again, but there is no doubt that the second great advantage of having had television actually operating before the war was to be found in the relatively large number of men who, knowing something of TV, were able to be converted into radar engineers and technicians in a very short time. It is a noteworthy fact that many of the most notable television engineers in Britain at the time became equally famous among those in the know for their work in developing radar and other electronic projects from the stage of laboratory curiosities to being major war-winning factors. If ever Britain had a successful "secret weapon," it was her supremacy at the time in the knowledge and application of electronics. And it was this same supremacy which enabled the unparalleled manufacturing capacity of the United States to play the part it did in winning the war. These statements, which we and many others, too, hold to be incontrovertible facts, show just how great a premium we should at this moment place on electronics. Here in Australia the radio industry rose to the occasion and played a very important part, albeit a small one in producing radio equipment not only for our own forces, but for British and American ones as well. At the moment, however, we are hardly "in the swim" as far as practical knowledge of the latest electronic weapons is concerned. N or do we have the facilities for making great contributions towards the development of new devices, but when, and if it comes to the point, we shall again be able to make a worthwhile contribution to the overall electronic war effort. The point we wish to make here is that our usefulness will be in direct proportion to the experience we shall have gained in modern electronic technique by the time we are called upon to assist, and that by embarking on a television programme we can do a great deal, in a strictly peaceful manner, to fit ourselves for what may be the greatest emergency ever. This point, we believe, should be given the most serious consideration by the Government when they are weighing up the pros and cons of TV in this country.