History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Radio in ANZ/Issues/1923 04 18

3 Link to Issue PDF WorldRadioHistory.com's scan of Radio in Australia and New Zealand - Vol. I No. 02 - 18 April 1923 has been utilised to create the partial content for this page and can be downloaded at this link to further extend the content and enable further text correction of this issue: Radio in ANZ 1923 04 18 In general, only content which is required for other articles in this Wikibook has been entered here and text corrected. The material has been extensively used, inter alia, for compilation of Biographical articles, Radio club articles and Station articles. Front Cover Issued every second Wednesday — Sixpence RADIO IN AUSTRALIA & NEW ZEALAND — incorporating "Sea, Land and Air" VOL I. — APRIL 18, 1923 — No. 2 (Start Graphic Description) DANCING TO RADIO MUSIC. (Underwood Photo) (End Graphic Description) Registered at G.P.O., Sydney, for transmission by post as a newspaper. Inside Front Cover - Wireless Press Ad The Wireless Man's BOOKSHELF PRACTICAL WIRELESS TELEGRAPHY By ELMER E. BUCHER. More than 85,000 copies of this book have been sold to date. It is used in practically every school, college and library in this country. Used by the U. S. Army and Navy. PRACTICAL WIRELESS TELEGRAPHY is the recognised standard wireless text book. It furnishes much information of utmost value in regard to the very latest styles of wireless sets now in use. It is the first wireless text book to treat each topic separately and completely, furnishing a progressive study from first principles to expert practice. Starting with elementary data, it progresses, chapter by chapter, over the entire field of wireless fundamentals, construction and practical operation. The 340 illustrations, especially drawn, form a complete diagrammatic study, and impress upon the reader's mind a pictorial outline of the entire subject. Many of these illustrations reveal details of construction of the newest types of sets and apparatus never before published. PRACTICAL WIRELESS TELEGRAPHY is a practical man's book, from cover to cover, and up to the minute. Size, 6¼ x 9¼ inches, 352 pp., handsomely bound in full cloth with cover stamping in gold and black. PRICE, 13/-, POST FREE. A.B.C. OF WIRELESS BY PERCY W . HARRIS. ri'his wonUerful Jittle book hns been specially prep:.lr@-d for those who are desirous 0f getting a good knowledge of wirele:;s without del\'ing into text books. 64 Pages, well Illustrated, Pricet 9d,, post free. ARTS AND SCIENCE SERIES. These little books fi ll :1 long felt w::rnt nmoug begin ners in radio. They are so simply written that you can't fail to understand. wlrn.t the author is trying to t ell you. No. 3.-LESSONS IN WIRELESS TELEGRAPHY, by .\. P. )Jorgan. A systematic Elementary Course in the Principles of \Vireless Telegraphy and the Eleetri<:a l Laws upon whicll it d ependti, No, 4.-THE OPERATION OF WIRELESS Tl:LEGRAPH APPARTUS, by A. B. Cole. A prac:tical Handbook f1illy expla ining some of the methods whereby the Radio Experimenter and Operafoi.· may secure the gren test P-ffici ency from his instruments. No, 5.-WIRELESS CONSTRUCTION AND INSTALLATION FOR BEGINNERS, by A. P. )!organ. A practical Handbook, giving detniled instruction and operation of n boy's V\Tireess Outfit. No, 6 .-EXPERIMENTAL WIRELESS CONSTRUCTION, by A. P. Morgan. A practicnl Handbook, ~iving detailed instruction for Building, Installing and Opera ti ng Arna teur Wireless Telegrnphy Appara tns. No. 7-8-9.-HOME MADE ELECTRICAL APPARAT , in three vol1.1 mc:S, by A. M. Powell. A Practicnl H:11:ndbook for the Amateu1· Experimenter. Rold separately. No. 10.-HOME-MADE TOY MOTORS, hy A. P . ~forgnn. A practical Handbook, giving detailed instructions for Building Simple but Operative Electric Motors. Paper Bounrl, Illustrated. Price each , 2/3; post free, Magnetism and Electricity for Home BY H , E . PENROSE. The lucid wuy in which the a uthor puts the matter before the readt"r: the sequence fo llowed (proceed ing from the known to the unknown); t he numerous analogies a nd associations with Ql'dinary everyday things: an(l the excellen t sketf'hes and diagrams, togeth er with test question~ and summaries, make the work admirallle for self-study or as a book for school use. 515 Pages; 224 Diagrams. Price, 9/-; post free , OBTAINABLE FROM LEADING BOOKSELLERS or THE WIRELESS PRESS: Australasia Chambers, WELLINGTON, N.Z.; 97 Clarence Street, SYDNEY; 422 Lt. Collins Street, MELBOURNE P.25 - Contents Banner RADIO in AUSTRALIA & NEW ZEALAND Incorporating "Sea, Land and Air" Managing Editor: S. E. TATHAM Associate Editor: M. DIXON CONTENTS Volume I. APRIL 18, 1923 Number 2 P.25 - Contents CONTENTS. Broadcasting in Australia . . . Page 27 Radio in the Country . . . Page 27 The Spark of Life . . . Page 28 Romance of Radio . . . Page 30 Victorian Experimenter at Work . . . Page 33 Trans-Pacific Tests . . . Page 34 The Experimenters' Corner . . . Page 36 Will Randwick See This? . . . Page 37 In Radio Land . . . Page 38 Electronic Valve Precautions . . . Page 41 Note on Control of Regeneration . . . Page 41 Call Letters . . . Page 42 The Wonder Man of Paris . . . Page 44 Radiofun . . . Page 45 Club Notes and News . . . Page 46 Queries and Answers . . . Page 48 P.25 - Publication Notes Published by: THE WIRELESS PRESS, 97 CLARENCE ST., SYDNEY; 422-24 Lt. Collins St., Melbourne; Australasia Chambers, Wellington, N.Z. PRICE, 6d. per Copy; Subscription Rate, 10/- per annum (26 issues) throughout Australia and New Zealand; Foreign Rate, 12/6 (26 issues) OVERSEAS REPRESENTATIVES: Canada and United States of America: The Wireless Press Inc., 326 Broadway, New York City Great Britain: The Wireless Press Ltd., 12-13 Henrietta St., London, W.C.2 P.26 - Photo of Marconi (Start Photo Caption) SENATORE GUGLIELMO MARCONI, G.C.V.O., LL.D., D.Sc., M.I.E.E. (End Photo Caption) P.27 - Radiotorial Broadcasting in Australia The decision of the Postmaster-General to hold a conference of all parties interested in radio broadcasting in Australia is a commendable one. In some quarters dissatisfaction has been expressed at the delay which has occurred in defining the position of those who wish to undertake the broadcasting of concerts, etc., in the Commonwealth. A little calm consideration will convince those people that a matter of this kind requires much careful consideration in order that the best possible results may be achieved. At all costs Australia must avoid the chaos which characterized the commencement of broadcasting in America. At the outset there it was anybody's business to transmit broadcast items, and the consequence was that those who should have benefited through the inauguration of broadcasting reaped a whirlwind of confusion. True to tradition, England was more conservative in making a beginning, and as a result was able to profit by the mistakes revealed in America's haphazard methods. It is only in recent months that broadcasting has been undertaken to any great extent in England, but that it has been attended by highly successful results is beyond question. Therefore, no apprehension need be felt that Australia is likely to suffer any serious consequences through the delay that has occurred. On the contrary, there is good ground for believing that when broadcasting does commence here it will be carried out in a more up-to-date and orderly manner than in any other country in the world. It is obvious that the regulations will be framed with that object in view, and as improvements in radio apparatus are constantly being designed the delay may easily prove to be a blessing in disguise. He would be a brave man who would undertake to prophesy, with any pretensions to accuracy, just how far radio is going to revolutionize the means of communication in Australia in the next ten years. The future is practically at the mercy of this distance-annihilating agency, and what we regard as an accomplishment to enthuse over to-day will very probably be an ordinary incident a few years hence. The result of the deliberations of the Melbourne Conference, when put into effect, may be expected to satisfy even the most exacting in the matter of broadcasting in Australia. With the general public educated to understand the benefits that are to be derived from the installation of home receiving sets, it may be confidently asserted that radio circles in Australia will experience the boom which has followed the commencement of broadcasting in overseas countries. Radio in the Country The Wingham Municipal Council (N.S.W.) is to be commended on its enterprise in seeking information as to how far radio telephony will benefit the people of isolated districts of Australia. It is a healthy sign when public bodies evince interest in such up-to-date matters as the installation of radio receiving and transmitting sets in order that people who are doing valuable pioneering work in the country might enjoy some of the pleasures available to those who live in the big centres of population. There is nothing more depressing than the deadly montony which settles upon those who are out of touch with the daily news of the world. The extension of mail services and telephone facilities, while of considerable value to country dwellers, can never render the same service as radio telephony. Too often have country people been accused of harbouring out-of-date ideas, but the step taken by the Wingham Council effectively destroys the foundation on which such a charge could be built. Those interested in the commercial aspect of radio in Australia are essentially men of progress, and may be relied upon to place the full benefit of their experience at the disposal of any public body that desires to exploit the possibilities of radio for the common good. Rural settlement is going to receive a tremendous impetus in the near future when would-be settlers realize that country life does not mean the severing of intercourse with the outside world, as it did a few years ago, and as it still does to a more or less extent to-day. It is infinitely better that the progress of radio in linking up isolated portions of the country with the big cities should be slow and sure rather than hasty and unsatisfactory. The moral effect of the latter would be the reverse of what is required to encourage the general public to place absolute faith in the value of wireless as a means of communication. The time is not far distant when all who desire to do so will be able to participate in the benefits of radio broadcasting. In the meantime it will be a good thing for Australia if many more public bodies follow the action of the Wingham Council in seeking information as to how far wireless telephony will benefit the people who live in isolated localities. P.28 - How Wireless Saved "Mindini's" Passengers and Crew (Start Photo Caption) (End Photo Caption) The Spark of Life. How Wireless Saved "Mindini's" Passengers and Crew. Operator's Graphic Story. By staff writer, no byline ONE needs to hear the story of the Mindini disaster first-hand to appreciate the heroism of all who participated therein — a heroism born largely of the knowledge that within a few minutes of the happening the radio call for help had been picked up and broadcasted to all ships and coast stations within a wide range. Wireless Officer's Story. The story told by Mr. R. Jordan, Wireless Officer of the Mindini, is a graphic one. He went off watch at 2 a.m. on the morning of March 8, and was soon wrapped in sound slumber. At a few minutes to 4 o'clock he was awakened by a severe bump. Wireless men are accustomed to thrills, and the ability to size up a situation quickly, is almost second nature to them. Consequently it was but the space of seconds till Mr. Jordan had realized that the Mindini was ashore on Mellish Reef. At the same instant he was summoned to the bridge, where he was informed of the ship's position, and given orders to broadcast the S.O.S. call. S.O.S. Call Goes Out. Back in the wireless room the operator nerved himself for the task of transmitting the call on which the safety of all on board depended. For the space of three minutes the magic spark hissed through space, and hardly had the calls ceased when Townsville Radio Station — distant 540 miles — responded. To use Mr. Jordan's own words: "The signals from Townsville indicating that our message had been picked up was sweet music in my ears, and imbued me with feelings of confidence in our chance of speedy rescue." The atmospheric conditions were exceedingly unfavourable for radio reception at the time, and prior to Townsville's response there was some doubt as to whether the calls would be heard by the coast stations. Once communication was established a request was made to Townsville to broadcast the call to other stations. This was immediately complied with, and Sydney, Melbourne and Thursday Island all received and passed on the tidings that the Mindini needed help. After the wireless officer had satisfied himself that the ship's perilous position was being broadcasted to vessels along the coast, he concentrated his attention on picking up any ships that might happen to be within easy range. It was felt that if this could be accomplished the chance of being towed off within a short time was exceedingly bright. Japanese Ship Responds. At five minute intervals the S.O.S. call was sent out, and at 9 a.m. — five hours after the ship struck — the Tohoko Maru, bound from Sydney to Hong Kong, answered the call. She was then about 95 miles off, and advised that she was coming to render assistance. An hour later the Nauru Chief, on the trip from Sydney to Nauru, signalled that she was 170 miles off. To the request of the Mindini's operator that she should alter her course to bring her to Mellish Reef, she immediately responded. Coast Stations Busy. Meanwhile the Australian coast stations had been busy, and the Montoro, approaching Townsville, and the Morinda, bound from Rabaul to Samarai, both signalled that they had picked up word of the Mindini's plight, and were racing to her assistance. Those on board the stranded vessel had by this time realized that it was only a matter of hours before help arrived. They were imbued with a quiet confidence from the very moment that Captain Voy advised them that the radio call had been heard and help was coming. Landing on Mellish Reef. It was necessary, however, to make their position secure, and hence preparations were made for landing on the island. These preparations were in charge of the Chief Officer (Mr. McLean), who exhibited great skill and coolness in piloting the boats over the 10 or 12 miles of open sea to the lee-side of the island. The vessel lay only about a mile off the island, but it was impossible to proceed there direct owing to the dangerous reef which intervened. While these preparations were proceeding the Tohoko Maru, the Nauru Chief and Townsville station were kept in continuous wireless call. Late in the afternoon the first-named vessel was advised by the Mindini to proceed direct on her voyage, as it was impossible for her to reach the stranded ship before nightfall. When night fell the Mindini was broadside on to the reef, and the water was pouring into the holds and engine room. At 9 p.m. the dynamos showed signs of weakening, despite the efforts of the engineers. Emergency Gear Used. At midnight they were both submerged, but communication was kept up by means of the emergency gear, which had a good range and was in splendid working order. In the early hours of the morning the ship was at an angle of about 50 degrees, and those on board experienced some anxious moments. Sleep was impossible, and the time was occupied in recounting sea stories and other incidents. "Nauru Chief" Arrives. With dawn came the rescue ship, Nauru Chief. Words fail to describe the feelings of relief and thankfulness with which those on board watched her steam to within close range. As one passenger declared: "It was the most inspiring sight he had ever witnessed." After exchanging messages regarding details of rescue work, the wireless officer closed down his station, and went on deck. The work of transferring passengers, crew and baggage to the Nauru Chief occupied some time, but at 11 a.m. Captain Voy left the stranded vessel. The next task was to pick up the passengers and members of the crew who had been landed on the small, low, coral island, which was practically devoid of vegetation. Their feelings of thankfulness at being taken off were easier to imagine than describe. No shelter of any sort was available, but the women had been accommodated for the night in a tent, which was erected for the purpose. The only life on the island was thousands of birds, which the passengers say were infested with lice. This, combined with the objectionable odour arising from thousands of decaying eggs had a most distressing effect on those who were compelled to spend the night there. Had there been no radio installation on the Mindini to summon assistance a stay of at least a fortnight or three weeks on this unsavoury spot was practically inevitable. A Link with the Past. An interesting discovery touching an incident which happened many years ago was made by one of the passengers during the afternoon. Noticing a bottle standing erect on an elevated spot on the island, he commenced scratching away the earth, and just beneath the surface a human skeleton was unearthed. A member of the Mindini's crew, on learning of the discovery recalled that many years before a death occurred on a sailing vessel while in the vicinity of Mellish Reef. A boat conveyed the corpse ashore, and it was interred in that lonely spot, with only the screeching of the wild birds and the subdued roar of the waves breaking on the wide coral reef to lull the restless spirit to sleep. Friends in Need. Immediately the shipwrecked passengers and crew boarded the Nauru Chief they were treated with the utmost courtesy and attention. The cabins were at once made available to the womenfolk, and despite the overtaxed condition of the ship, the three days which were spent on board prior to reaching Samarai were crowded full of pleasant incidents, so much so that all hands were sorry when the time for parting arrived. From Samarai the party proceeded by the Morinda to Cairns, where they boarded the Marella en route for Sydney. Radio Helps all Through. In addition to the actual work of transmitting the distress signals and other messages incidental to the rescue, wireless was employed to complete the whole of the arrangements for the transhipment of the passengers and crew at the various ports. In response to a request by radio, the Morinda was ready to receive her guests on their arrival at Samarai, and similarly when she landed them at Cairns the Marella, which had been detained for that purpose, took them on board for Sydney. Those Who Helped. It would be unfair to close the story of such excellent rescue work as that performed in the Mindini disaster without paying a due tribute to the valuable and sustained work carried out by the various wireless officers, both at coast stations and on board ships. The chief figure, of course, was Mr. Jordan, Wireless Officer of the Mindini. He was singularly unconscious of the valuable work he performed, but not so the passengers and crew of the ill-fated steamer. They paid glowing tributes to the value of wireless in saving the lives of all on board, and every mention made of the happening was coupled with the name of Mr. Jordan. The staff of the Coastal Radio Station at Townsville also performed splendid service, and a similar tribute must be paid to the staffs of the Sydney, Melbourne and Thursday Island stations. At sea the determination of the wireless officers on the Nauru Chief and Morinda to render assistance if it were humanly possible to do so was exemplified by the fact that the former, Mr. E. S. Bailes, remained on duty continuously for 29 hours. Mr. Haddock, of the Morinda, also kept up a sustained watch of over 22 hours. P.30 - Marconi Tells The Story Romance of Radio. Twenty Years of Progress. Marconi Tells the Story. It is always interesting to glance back over the years marking the early history of any great invention or discovery. When that discovery happens to be radio, and the gentleman in a reminiscent mood Senatore Marconi, one can rest assured that something of more than ordinary interest will be revealed. Quite recently Marconi lectured before a joint meeting of the American Institute of Electrical Engineers and the Institute of Radio Engineers in New York, in the course of which he said: The first occasion on which I had the honour of speaking before the members of the American Institute of Electrical Engineers was of a very festive nature. It is more than twenty years ago to be exact, on January 13, 1902 (there was not then any Radio Institute in existence) — and on that date, memorable for me, I was entertained by more than 300 members of your Institute at a dinner at the Waldorf-Astoria in this city. I was offered that dinner following my announcement of the fact that I had succeeded in getting the first radio signal across the Atlantic Ocean. The function was one I shall never forget, and what has left the greatest impression on my mind during all the long twenty years that have passed is the fact that you believed in me and in what I told you about having got the simple letter "S" for the first time across the ocean from England to Newfoundland without the aid of cables or conductors. It gives me now the greatest possible satisfaction to say that, in some measure, perhaps, your confidence in my statement was not misplaced, for those first feeble signals which I received at St. John's, Newfoundland, on the 12th of December, 1901, had proved once and for all that electric waves could be transmitted and received across the ocean, and that long distance radio telegraphy, about which so many doubts were then entertained, was really going to become an established fact. A very great impulse has been given to radio telegraphy and telephony by the discovery and utilisation of the oscillating electron tube or triode valve based on the observations and discoveries of Edison and Fleming, of those of De Forest and of those of Messiner in Germany, Langmuir and Armstrong in America, and H. W. Round in England, who have also brought it to a practica1 form as a most reliable generator of continuous electric waves. The Vacuum Tube. As the electron tube, or triode valve, or valve, as it is now generally called in England, is able, not only to act as a detector, but also to generate oscillations, it has supplied us with an arrangement which is fundamentally similar for both transmitter and receiver, providing us also by a simple and practical method with the means for obtaining beat reception and an almost unlimited magnification of the strength of signals. A result of the introduction of the triode valve has been that the basic inventions which made long distance radio telegraphy possible have become more and more valuable. It has been so far our practice to use a plurality of tubes in parallel at our long-distance stations. High power has been obtained in practice up to 100 kilowatts in the antenna by means of a number of glass tubes in parallel, and for the present we are standardising units capable of supplying four kilowatts to the antenna, in the numbers required and sufficient for each particular case. Some difficulty was at first experienced in paralleling large tubes in considerable numbers, but no difficulties now occur with groups of 60 bulbs working on voltages of 12,000 on the plate. I am told that no insurmountable difficulty would be encountered if it were desired to supply 500 kilowatts to the antenna from a number of these bulbs. The life of the bulbs has been very materially increased, and the 4-kilowatt units are expected to have a life, which, based on a great number of tests carried out both in the laboratory and at our Clifton station, should be well in excess of 5,000 hours. The development of single unit tubes of considerable power is also progressing. We have lately concentrated on the production of high-power tubes made of quartz, and two sizes of each bulb are now being made, one for 25 kilowatts to the aerial and another for 75 kilowatts, but it is not expected that the efficiency of the high-power single units will be as good as that of the multiple units, and the work on the large tubes is being considered so far as experimental. Very careful investigations have been carried out by Mr. H. W. Round of all the losses in the loading coils and other parts of the tube circuits, and actual measurements on considerable power have shown that an over-all efficiency from the input power on the plates of the tubes to the aerial of 70 per cent. is possible with a complete avoidance of harmonics, that is, an efficiency from the power input to the plates of the tubes to actual radiation into space of about 35 per cent. On shorter wave stations it is quite practicable still further to increase this efficiency, although possibly it is hardly worth the extra expense involved. We have at present one station in England working on a 3,000-metre wavelength with a height of mast of 100 metres, which has an efficiency from plates to radiation into space of 40 per cent. In high-speed transmission we are maintaining public services at 100 words per minute to two places in Europe, namely, Paris and Berne, using a single aerial transmitter with two wave-lengths on the same aerial, and although the operation of utilising a single aerial for two wavelengths is not an advisable one for high-power work, it has certain points to recommend it in medium-power work, where the consequent loss of efficiency can be made up for by a slight increase of power. These two waves are working duplex to both Paris and Berne, and practically all traffic is taken on printing machinery, although there are occasions when, because of static, reception has to be done on undulator tape, and, in some rare cases, on the telephones, by sound. The reception at these shorter distance stations is carried out by means of a cascade arrangement of high and low frequency tuned amplifier circuits attached to the directional aerial system of the Bellini type, arranged for unidirectional reception when necessary. Where Static Comes From. During my present journey across the Atlantic on board the yacht Elettra we noticed that up to about half-way across (apart from the effects of local storms) static interference appeared to be coming from the European and African continents, while at more than half-way across they were coming from westerly directions, that is, from the American continent. The changing over of the direction of origin of these disturbances has also been noted under similar circumstances by Mr. Tremellen in crossing the Pacific. The protection of receivers against the troubles of atmospherics or static can only be, and is likely to continue to be, a relative matter, as it is quite obvious that a static eliminator under certain conditions will cease to be effective, where the static arrives with much greater intensity than had been anticipated, and will also frequently fail when, in consequence of the weakness of the received signals, application has to be increased to any considerable extent. Receiving Developments. In 1920, however, an important step was made by Mr. G. Mathieu as to the path to be followed out in order to obtain a practical solution of the problem. This consisted in the design of a new type of air-core tuned inter-valve transformer arranged in such a manner as to possess only an extremely electrostatic capacity between the windings, and having its effective primary impedance about equal to the effective internal plate to filament resistance of the tube in use when the secondary circuit was brought into resonance with the frequency of the oscillations to be amplified. The results to be achieved during the first tests of these new transformers appeared to be quite amazing, the amplification factor for one tube having passed suddenly from five to about fifteen for the particular tube tested, whilst the stability proved incomparably better than what had been obtained previously, even when the grid of the tube was kept to a negative potential of one or two volts. The Importance of Short Waves. rung only when the aperture of the The study of short waves dates sending reflector was directed toward from the time of the discovery of the receiver. electric waves themselves, that is from Since these tests of more than the time of the classical experiments twenty years ago practically no reof Hertz and his contem'poraries, for search work was carried out or pubHertz used short electric waves in all lished in regard to short waves, so his experiments, and also 1nade use ··· far air-I· can ascertain; .for a · ve-ry of reflectors to prove their character- long period of years. istics, and to show among many other Most of the facts and results which things that the waves, which he had I propose to bring to your notice are discovered, obeyed the ordinary opti- taken from Mr. Franklin's paper. cal laws of reflection. 'l'he waves used had a length of two As I have a\ready stated, short metres and three metres. With electric waves were also the first with these waves disturbances caused by which I experimented in the very static can be said to be almost nonearly stages of wireless history, and existent, and the only interference I might perhaps recall the fact that experienced came from the ignition when, more than 26 years ago, I first apparatus of automobiles and motor went to England, I was able to show boats. to the late Sir Wm. Preece, then En- The receiver at first used was a gineer in Chief of the British Post crystal receiver, whilst the reflectors Office, the transmissiOii' and recep- employed were made of a number of tion of intelligible signals over a dis- strips of wires tuned to the wave tance of 1¾ miles by means of short used, arranged on a cylindrical para" ·aves and reflectors, whilst, curi- bolic curve, with the aerial in the ously enough, by means of the an- focal line. tenna or elevated wire system, I The tests ~;ere continued in Engcould only get at that time signals land at Carnarvon during 1917. over a distance of half a mile. With an improved compressed air The progress made with the long spark gap transmitter, a three-metrr wave or antenna system was so rapid, wave, and a reflector having an apei·so comparatively easy, . and so spec- ture of two wave-lengths and a height tacular that it distracted from the of 1.5 wave-length, a range of more short waves, and this, I think, was than twenty miles was readily obregrettable, for there are very many tained with a receiver used without problems that can be solved, and a reflector. numerous most useful results to be In 1919 further experiments were obtained by, and only by, the use of commenced b.r Mr. Franklin at Carthe short wave system. Directional Transmission. At that lecture I showed how it was possible, by means of short waves and reflectors, to project the rays in a beam in one direction only, instead of allowing them to spread all around, in such a way that they could not affect any receiver which happened to be out of the angle of propagation of the beam. I also described tests carried out in transmitting a beam of reflected waves across country over Salisbury Plain, in England, and pointed out the possible utility of such a system if applied to lighthouses and lightships, so as to enable vessels in foggy weather to locate dangerous points around the coasts. I also showed results obtained by a reflected beam of waves projected across the lecture rooms, and how a receiver could be actuated and a bell The Importance of Short Waves. rung only when the aperture of the The study of short waves dates sending reflector was directed toward from the time of the discovery of the receiver. tance which is exceedingly high. The efficiency input to the tubes to aerial power is between 50 and 60 per cent., and about 300 watts are actually radiated into space. With the reflectors in use at both ends, speech is usually strong enough to be just audible with a 1 to ½ ohm shunt across a 60-ohm telephone. With both reflectors clown and out of use, speech is only just audible with no shunt. By means of suitable electron tubes or valves it is now quite practicable to produce waves from about · 1z--m:etr-es· and · ttpward, utilizi11g · a power of several kilowatts, and it is also practicable to utilise valves in parallel. Reflectors, besides g1vmg direct. iona l working, and econom1smg power, are showing . another unexpected advantage, which is probably common to all sharply directional systems. It has been noted that prac. tically no distortion of speech takes place, such as is often noticed with non-directional transmitters and receivers, even wlwn using short wav~s. It has thus been shown for the first time that electric waves of the order of 15 to 20 meters in length are quite capable of providing a good and reliable point to · point directional service over quite considerable rang~. , I have brought these results and ideas to your notice as I feel-and perhaps you will agree with methat the study of short electric waves, although sadly neglected practically all through the history of wireless is -:till likely to develop in many 11n'expectecl directions, and open up new fields of profitable research. Broadcasting. No remarks from me or from anyone else are required to tell you what has already been done with radio in America as a means of broadcasting human speech and other kinds of sound which may also be entertaining if not always instructive. In thousands of homes in this country there are radio-telephonic receivers, and intelligent people, young and old, well able to use them — often able to make them — and in many instances contributing valuable information to the general body of knowledge concerning the problems, great and small, of radio telegraphy and radio telephony. P.33 - Victorian Experimenter at Work Victorian Experimenter at Work. Up-to-Date Station at Caulfield. Mr. Fall's Good Work. The interest and enthusiasm of the radio experimenter is almost invariably revealed in the efficiency of the station which he has erected to follow up his hobby. Of course it sometimes happens that an intensely enthusiastic amateur is prevented, by financial considerations, from equipping his set as he would like. Such a drawback, however, is invariably only temporary, and most experimenters sooner or later contrive to get together the set they require. To accept anything less is contrary to the spirit which in the first instance impelled them to undertake radio research. A visit to the up-to-date station erected by Mr. L. Fall at Ormond (Victoria) will unquestionably prove an eye-opener to those not fully acquainted with the progress made in recent years by Australian experimenters. Mr. Fall obtained a close insight into radio communication work while he was on active service in France, and on his return to Australia devoted himself whole heartedly to extending his knowledge of the science. The result is today strikingly apparent to the visitor in search of information who drops in at Mr. Fall's home any evening. The operation of establishing communication with the outside world is a simple one. The headphones are adjusted, a few dial indicators turned, the valve detector glows and mystic voices come floating in sharp and clear. Melbourne radio station is heard calling up some ship within range, perhaps to despatch a message of farewell to some friend or relative on an outward voyage; a moment later a deep voice is heard calling the police patrol car to say that there is nothing to report; and then a shrill whistling note indicates that Sydney has something to say. And so it goes on. In the space of half an hour one is able to realize in a small measure the myriad activities of the busy radio world. After a brief lull the listener hears a voice announcing that the Melbourne Office of Amalgamated Wireless is broadcasting the usual Monday night concert. A moment later the strains of music come floating in, and the listener is able to appreciate the feelings of rapture with which dwellers outback will embrace the opportunity of receiving broadcast concerts when that long-looked for innovation commences in Australia. By way of showing the capacity of his set for receiving messages from high-power stations overseas, Mr. Fall introduced a large coil of wire, estimated at 4½ miles long. A few moments devoted to "tuning," and signals from France and America came in quite audibly. The following is a description of Mr. Fall's set: The aerial is of the inverted L shape, and consists of two poles 45 feet high and 93 feet apart, with four wires. The earth consists of a water pipe 4 feet 6 inches from the set. On left-hand top corner is a crystal receiver, consisting of two variable condensers (primary and secondary), two honeycomb coils, two detectors, so arranged to switch from one or the other. Fixed condenser and, aerial, earth and telephone terminals. At the right-hand top corner is the long wave coil, with Jackson's plugs arranged so that any wave length from 2,000 to 30,000 metres can be obtained by plugging in to the respective coils. Bottom right-hand side is the short wave set, which is placed in a cabinet. The top row on the ebonite slab shows the grid condensers (variable), long and short wave condensers, variable high tension switch and amplifying valve. Second row: aerial tuning condenser (variable), filament resistance, detecting valve and second filament resistance. Bottom row: high tension switch, double-pole switch for placing aerial tuning condenser in series or parallel and low tension switch. In front of the switches is a pair of Baldwin telephones. Standing upright on the left-hand side is a Brown's loud speaker; beside it on the right is the telephone transformer. Behind the speaker is a step-down transformer. The results obtained from this set are very satisfactory. Such stations as Stavanger (Norway), Bordeaux (France), Tachoosh (America), New York Radio Central and other American stations being readable. The telephony concerts broadcasted by the Amalgamated Wireless, Ltd., are readable at 40 feet from the phones. Telephony also has been received from Raratonga, New Zealand. P.34 - Trans-Pacific Tests Trans-Pacific Tests. Ideas for Competitors. By J. G. Reed (Joseph Griffiths "Joe" Reed, XABP-2JR - SSD) SOME time ago the, writer pro mised readers of Sea, Land and A.ir further information regarding amplifiers suitable for the reception of signals from long-distance, short-wave stations. Since then many important experiments have been carried out while getting a suitable receiver ready for the trans-Pacfic tests in May this year. The distance over which the signals will travel between California and the East Coast of Australia is in the neighbourhood of 7,000 miles, and as a consequence they will arrive in a very feeble condition after their long journey. Amplification by at least one valve at radio frequency must be made before the signals are handed along to the detector. The valve as a detector alone is not a very sensitive device, as will be seen after studying Figure 1, which shows the variation of plate current with respect to grid potential. For operation as a detector the valve is adjusted so that it functions at either the top or bottom bend of its characteristic curve. The energy consumption both in the grid and the plate circuits is least when the valve is operated on the lower portion; that is, when a negative potential is impressed upon the grid either by a potentiometer or leaky grid condenser. Variation of the grid poten- tial positive and negative to normal is shown along the vertical line marked grid voltage. If the amplitude of the impressed oscillations is very small, as in case "a, " the portion of the plate current curve over which it has influence will be sensibly equal to a straight line, and the change in plate current will be merely a magnified duplicate, whose effect upon the telephone receivers will be zero as the variations swing equally to each side of the normal value of the current. If the amplitude is increased by means of preliminary amplification to that shown in case "b," much better results will be obtained, for advantage can now be taken of the non-linear property of the curve. Variations of the grid potential in a positive direction will cause a greater increase in plate current than takes place in the opposite direction when a negative potential is applied. The plate current is no longer symmetrical in its variation relative to normal, with the result that rectified pulses of current as shown in the dotted line flow through the telephones. The above explanation is applicable to hard valves, or those ·which have been exhausted to a fairly high degree of vacuum, but in those containing slight traces of gas, such as Expanse "B" or Radiotron "UV200," a slightly different action takes place. When the electrons emitted' by the filament reach a certain critical velocity they are able to strike the residual molecules of gas in the tube with such force that the latter are broken up and become ionized, causing an abnormal change in the plate current. If the filament current and plate voltage are regulated slightly below this point remarkably efficient rectification takes place. In the experiments being carried out by the writer a soft valve is used as a detector, and particular attention is paid to close variation of the filament current and plate potential. If no vernier filament resistance is available, one can be easily constructed as follows: Obtain a piece of hard rubber rod one inch in diameter and four inches long, which must be placed in a lathe and a light thread of about twenty to the inch put on. In this groove is wound a spiral of Eureka resistance wire of No. 24 gauge. If this size is not available use either No. 22 or26. Into the end of the hard rubber is screwed a piece of -¼" brass rod 4" long·, to which the resistance wire is soldered after the end has been made fast to the former so that it will not unwind. Mount the outfit according to Figure 2. A sliding contact is furnished by Clip C, and if a small centre punch mark is made on one side of it a fine variation of current can be obtained by turning the resistance unit around by the knob H, when the wire in the groove will engage with the impression on the contact _ clip, and by its screw action a gradual advance will be made. Rough adjustment of resistance can be obtained by sliding the rod up and down in the clip. To ensure smooth action when this takes place, round off the edges of the contact clip with a file, because it is likely to catch against the resistance wire. For the plate supply of the detector valve a separate high tension battery is recommended, which should work in conjunction with an A battery potentiometer to obtain the close control over the plate potential required for best results. The two microfarad condenser connected between the posi- tive terminal of the high tension battery and the negative of the filament battery provides a path of low impedance for the high frequency currents, otherwise, owing to the internal resistance of the plate battery and the potentiometer being common to all valves, self-oscillation is likely to be set up because of its auto-coupling effect. The grid condenser for the detector valve should be in the neighbourhood of 250 cms. (0.0003 microfarads), with a high resistance leak of two to three megohms between the grid and the filament terminal which gives best results. Adjusting the most critical soft valve will be considered an easy task after experimenting\ for a while with a short-wave multi-valve amplifier. The peculiar effects caused by the small internal capacities of the valves and other parts of the apparatus when attempting to receive signals below 400 metres would almost discourage even a dyed in the wool experimenter. Here is the way in which the writer attacked the problem, and if the procedure is followed by those interested in this subject much valuable time and temper will be saved. Commence with one valve as an amplifier, and understand its peculiarities before attempting a more ambitious programme. Two efficient methods of coupling are, available viz., tuned impedance and tuned transformer. The former is to be preferred owing to its simplicity and slightly higher efficiency on the lower wave lengths. For the inter-valve chokes use small variometers with four inch tubes for stators and three inch tubes for rotors. Each tube is wound with 30 turns of No. 24 D.C.C. wire. Details of the construction of these variometers appeared in a pre- vious issue of Sea, Land and Air, but for those who may have missed this article the sketch in Figure 3 will make the assembly clear. Figure 4 gives the diagram of connections for a receiver employing three valves as radio frequency amplifiers, and one as detector. The valves used for the amplifiers should possess the smallest possible inter-electrode capacity, and in this respect the V24, QX: and Q types are very suitable, owing to their very' short lead in wires to the grid and plate elements. The switches marked "S" are used to connect up the different stages of amplification as required. When one amplifier and detector are switched into circuit it will be noticed that as soon as the plate circuit' of the amplifier valve is tuned to resonance with the input circuit, it breaks into oscillation and acts as an autodyne receiver, producing beats with the incoming wave train. These oscillations are caused by the electrostatic coupling which exists between the plate and the grid of the valve, and can be stopped by either increasing the decrement of the grid circuit, clue to a slight positive potential applied by means of a potentiometer, or increasing the effective resistance of the plate oscillatory circuit to such an extent that the extra energy caused by this regeneration is just used up in overcoming the ohmic losses. With only one valve acting as a radio frequency amplifier it is an easy matter to apply the positive potential direct to the grid, as there is a connection of low resistance all the way; but when two or more are used and an attempt is made to impress this potential through the grid leaks, the high resistance of the latter path, combined with the fact that a small current flows when the grid is made positive, keeps the effective voltage much lower than that supplied by the potentiometer, and as all the amplifier grids are generally worked from the same potentiometer, the input circuit which connects direct is liable to have too high a potential impressed in the endeavour to control the other valves, with the result that the losses are so high as to seriously affect the strength of the incoming oscillations. Referring to Figure 4 it will be seen that the inductance of the variometer V and the capacity between the plate and :filament from the tuned coupling circuit for the next valve. If the resistance of this circuit exceeds a certain value the voltage generated across the internal capacity of the valve will not be sufficient to give rise to sustained oscillations. This at ·once affords an excellent means of controlling the regenerative property of the valve. Between the variometer and the plate connection insert a variable non-inductive resistance of about 200 to 300 ohms. An "Expanse" rotary potentiometer makes an excellent unit variable up to 250 ohms. The exact value of this resistance which will stop oscillations depends largely upon the ratio of inductance and capacity in the circuit, but for all ordinary valves, such as the V24 and QX:, it will be found quite sufficient. If a fixed inductance shunted with a small variable con denser is used to tune the plate circuit to resonance, the location of this resistance will have to be altered slightly. The tuning condenser may be considered as being in parallel with the capacity between the plate and filament; therefore, to get the resist- ( Continued from Page 35. ) ceived signals a separate heterodyne, When all the apparatus is asancesimilar to askance October 2022 in series with this combination as described by Mr. Chas. Maclurcan semblcd-preferably on a board about and the inductance, it must be con- in the March issue of Sea, Land and four feet long by one foot broadnected as shown in\ Figure 5. The Air, may be used, or else the detector commence as follows to tune it chances are-as in the writer's case valve can be ·made to generate its own through all the stages of amplifica- that all available potentiometers oscillations, as in the ordinarv re- tion. Loosely couple to the earth have been pressed into service for generative receiver, by tuning the lead or place several feet away from controlling· the input and detector plate circuit with an undamped the tuning apparatus a buzzer operplate circuits, and cannot be spared variometer. If the detector valve will ated wavemeter generating waves of for use as series resistance. This dif- not oscillate with the simple tuning· the desired frequency. Adjust the tun- ficulty was overcome in the following of its plate circuit, a small three- ing of the variocoupler and variomanner. plate vernier condenser connected be- meter in the plate circuit of the de- The text books tell us that the tween( its grid and plate terminals t ector valve, which is connected losses in a condenser or an inductance will usually get things going. through to the variocoupler by means caused by a series resistance can be of the switch, S4, which be on the ,represented by a shunt resistance of H.T: up contact, with all the others high value, bearing the relationship down. When loudest signals are ob- expressed in. the following formula: R tained with this valve, switch S4 r = 1/ R(2pi. f. C)Z, where r = the down and S3 up, connecting in one shunt resistance, R = the series re- L C. valve asl a radio frequency amplifier sistance, and C = the capacity in 1 0 before the detector. Variometer V3 the circuit. The correct valu·e to -~ I u:P•n must now be tuned to resonance, and make this resistance can be very 7 ., ___ --..J.__--1 if any tendency is shown by the set quickly arrived at by shun.ting the to break into oscillation, adjust the variometer or tuned anode circuit · · series or shunt damping resistance with a variable grid leak resistance until this just ceases. Continue this mounting. The . writer m:ade -this -- .... -- . -- . - . ..... - .. · - ------ . .. readjustment with three and then pitice of apparatus from a strip of , il•-...---------...•. four valves in operation. Slight r erubber two inches long, one inch wide t L.T · i adjustment of the tuning of the varioand one eighth inch thick, with a - Figure 5_ meters and resistances will be found terminal at each end. Pencil lines, necessary as each extra step of amusing an HB. drawing pencil, were 'I'he stray capacity effects due to plification is switched in. drawn between the · two terminals the body and hands-which are at until the oscillations just ceased, earth potential- moving about near 'l'a~e care that the space underneath the inductances and condensers of the and around the terminals is well set cause annoying fluctuations in rubbed with the pencil before screw- signal strength. 'I'o obviate this pro- ing down the former. A tinfoil vide an earth shield on the panel ac washer makes sure of the connection, commodating the tuning apparatus reand to prepare the surface of the quiring adjustment. Another method hard rubber for the pencil lines it is to use extension haildles' from the should have its surface glaze scraped control knobs of the variometers and off by means of a knife or fine sand condensers. These should be about paper.. twelve inches long, and _c<,msist of To produce the oscillations neces- hard rubber, fibre or other 'non-consary for the best reception of the re- ducting material.\ ' · · · When tuning for a distant station transmitting by means of continuous waves, best results are secured by using a local heterodyne oscillator, which should be varied over a band of wave lengths each side of that desired to be receiver, and when a signal is heard close tuning of the remainder of the circuit should be made. Readers experimenting with this class of apparatus will receive every assistance with their problems if queries are addressed to the Editor. P.38 - In Radio Land Radio Telephone Demonstrations in Melbourne. At least two highly successful demonstrations of radio telephony have been given in Melbourne recently, and on each occasion those present were both surprised and delighted at the results. The first was at a luncheon of the Rotary Club, at which Mr. L. A. Hooke (Melbourne Manager of Amalgamated Wireless, Ltd.) was the guest of honour. In the course of a brief address Mr. Hooke outlined the history of radio during the past 25 years. Subsequently a number of musical selections, news items, stock and share reports and weather forecasts were received on a small set equipped with a loop aerial 30 inches square. The speech was magnified by a "loud speaker," and all in the room were able to enjoy the various items without leaving their seats. That the demonstration was an eye-opener to many men who had previously only a very hazy idea of what radio telephony could accomplish, was evidenced by the expressions of surprise and pleasure heard on all sides at the conclusion of the luncheon. The second demonstration was given at Collins House, Melbourne, at which a number of gentlemen interested in Northern Territory holdings were present. Conversations were carried on with ease between Mr. Durack, M.L.A., of Western Australia, Mr. Massey Greene and Mr. Conacher, of Vesty's, Ltd., Darwin, at "Collins House," and Messrs. Miller and White at the Radio Station, Domain Road, South Yarra. It was the first time any of those mentioned had ever operated a radio set, but as evidence of the extreme simplicity of doing so it might be mentioned that not one of them experienced the slightest difficulty, and the results were all that could have been wished for. Marriage by Radio. Hotels May Not "Listen In." Why He Stayed Away. "RADIO" RECEIVES WARM WELCOME. Judging by the enthusiastic reception accorded the first issue of Radio, we were right in assuming that we could produce the class of magazine that wireless men wanted. Our first issue was sold out within a week of publication, despite the fact that sufficient copies were printed, as we thought, to supply the heaviest demand that could possibly be expected. To those agents who sent to us for extra supplies we express our regret at being unable to fill their orders. We have, however, taken care that such a happening shall not be repeated, and the extra large number of copies of this issue which have been printed should enable everyone who desires to purchase a copy to do so. We are grateful to the wireless enthusiasts of Australia and New Zealand for the support they have accorded us. It is our intention to go on improving each issue of Radio until it stands second to none in any part of the world. P.42 - Call Letters This is the second list of call letters of Australian and New Zealand ship and land stations. In subsequent issues of "Radio" further lists will appear, all of which should be preserved so that readers will have a complete list of both local and overseas stations.— Ed. CGA s.s. Australrange CGB s.s. Australplain CGC s.s. St. George CGD s.s. Australglen CGE s.s. Australford CGF s.s. Eurelia CGG s.s. Eudunda CGH s.s. Booral CGI Willis Islets Radio CGL s.s. Toromeo CGM s.s. Cooee CGN s.s. Australbrook CGO s.s. Manurewa CGP s.s. Sumatra CGQ s.s. Kurumba CGR s.s. Biloela CGS s.s. Kowarra CGT s.s. Melusia CGV s.s. Wyola CGX s.s. Macedon GABC H.M.A.S. Adelaide GABD H.M.A.S. Anzac GABF H.M.A.S. Australia GABH H.M.A.S. Brisbane GABK H.M.A.S. Encounter GABL H.M.A.S. Fantome GABM H.M.A.S. Geranium GABN H.M.A.S. Huon GABQ H.M.A.S. Marguerite GABR H.M.A.S. Melbourne GABS H.M.A.S. Parramatta GABT H.M.A.S. Platypus GABV H.M.A.S. Protector GABW H.M.A.S. Stalwart GABX H.M.A.S. Submarine Jl GABY H.M.A.S. Submarine J2 GABZ H.M.A.S. Submarine J3 GACB H.M.A.S. Submarine J4 GACD H.M.A.S. Submarine J5 GACF H.M.A.S. Submarine J7 GACH H.M.A.S. Success GACJ H.M.A.S. Swan GACK H.M.A.S. Swordsman GACL H.M.A.S. Sydney GACM H.M.A.S. Tasmania GACN H.M.A.S. Tattoo GACP H.M.A.S. Torrens GACQ H.M.A.S. Una GACR H.M.A.S. Warrego GACS H.M.A.S. Yarra GBE s.s. Niagara GBFV s.s. Arafura GBJ s.s. Benalla GBJD s.s. Waikouaiti GBKJ s.s. Marella GBKL s.s. Orcades GBLF s.s. Omar GBMP s.s. Wingatui GBNM s.s. Waitemata GBQ s.s. Nestor GBQP s.s. Wangaratta GBU s.s. Ulysses GBVK s.s. Talune GCBJ s.s. Surrey GCDK s.s. Kawatiri GCD y S.S. Kaiwarra GCFJ s.s. Port Curtis GCFK s.s. Woodarra GCJR S.S. Ormuz GCLN s.s. Otaki GCNQ s.s. Port Kembla GCNR s.s. Port Adelaide GCNY s.s. Waikawa GCPL s.s. Hymettus GCPM s.s. Katuna GCSV s.s. Diogenes GCTZ s.s. Naldera GCVB s.s. Narkunda GDBQ s.s. Waihemo GDF s.s. Gracchus GDJC s.s. Montoro GDKM s.s. Waiotapu GDPV s.s. Clan MacTaggart GDPW s.s. Clan MacTavish GDR s.s. Cufic GDU s.s. Tropic GDVZ s.s. Moldavia GDZR s.s. Atua GDZS s.s. Kurow GDZT s.s. Maheno GDZV s.s. Makura GDZW s.s. Manuka GDZX s.s. Maori GDZY s.s. Marama GFBC s.s. Mooltan GFBD s.s. Maloja GFBJ s.s. Mongolia GFBL s.s. Ballarat GFBM s.s. Balranald GFBN s.s. Baradine GFBP s.s. Barrabool GFWX s.s. Sophocles GFYB s.s. Maunganui GFYC s.s. Moana GFYD s.s. Moeraki GFYJ s.s. Mokoia GFYK s.s. Navua GFYL s.s. Taviuni GFYM s.s. Tofua GFYN s.s. Wahine GFYP s.s. Waihora GFYQ s.s. Waitomo GFZM s.s. Charon GFZP s.s. Minderoo GKL s.s. Matatua GLG s.s. Pakeha GNK s.s. Waipara GQA s.s. Ayrshire GQB s.s. Perthshire GQW s.s. Australind GRY s.s. Dorset GSB s.s. Port Macquarie GSF s.s. Shropshire GTJ s.s. Argyllshire GVBC s.s. Changsha GVBD s.s. Victoria GVBF s.s. Taiyuan GVM s.s. Banffshire GVS s.s. Clan Macgillivray GVU s.s. Clan Ross GVV s.s. Clan Ogilvy GWI s.s. Port Albany JAI s.s. Aki Maru JNL s.s. Nikko Maru JTG s.s. Tango Maru JYD s.s. Yawata Maru KDBL s.s. West Camargo KDCS s.s. Hollywood KEKB s.s. East Wind KJH s.s. West Wind MBT s.s. Rimutaka MCE s.s. Khyber MCP s.s. Ceramic MFQ s.s. Borda MFU s.s. Aeneas MFV s.s. Ascanius MFW s.s. Anchises MGG s.s. St. Albans MGK s.s. Demosthenes MGM s.s. Themistocles MGZ s.s. Khiva MHG s.s. Carpentaria MHY s.s. Paparoa MIL s.s. Palermo MJC s.s. Suevic MJQ s.s. Westmeath