Radio Review

Evening Star, Issue 19664, 17 September 1927, Page 15

Radio Review

-[By “HENRY.”;

Flashes from Everywhere.

TEEMS AND EXPRESSIONS. SIMPLE EXPLANATIONS. Tho following list is taken from Harmsworth’s ‘ Wireless Encyclopedia,’ and has been condensed and selected for this column by “ Henry ” : Dual Amplification.—The term is applied to a variety of circuits so arranged that one valve can bo made to do the work of two valves, for instance, employing one valve to amplify the audio and the radio frequencies simultaneously. Dull Emitter Valves.—A dull emitter valve is one used in radio work that has been specially designed and made to operate on a minimum voltage of heating of tho filament. Duo Terminal.—Terminal which lias an arrangement for clamping two wires simultaneously. Ear Pads.—Name given to a flexible device adapted to be placed on fhc phones to relievo the pressure on the ears of the listener. Earth.—Expression used to refer to the actual earth itself, and in an electrical sense to that side of the circuit which is connected to tho earth. Earth Capacity.—Term used for the capacity between tho plates of a condenser and the earth. The reading of a condenser is often affected by, the capacity due to the earth or surrounding objects. Earth Current.—A current of electricity present in the earth. Earth Return. —Earth return is the name given to the method adopted in all branches of electrical engineering in using tho earth itself as tho connection to one pole of any source of supply of electricity. Ebonite. —A form of vulcanite composed largely of rubber and_ sulphur, thoroughly mixed and vulcanised at a temperature of some 150 deg C. lor several hours. Edge Effect. —In condensers an effect on tho capacity of tho condenser due to tho lines of electric stress being curved at the edges. Electrode. —The terminal or pole of current carrying conductors separated by tho medium through which the current can flow from one to the other or others, whore more than two exist. Electrolytic Detector.—A detector which converts high-frequency current into direct current capable of causing sounds in an ordinary telephone receiver. Electrolytic Interrupter.—An instrument for breaking up very rapidly an electric current in order to produce au intermittent current of high electro mo- ! tivo force, as in the case of an inducj tiou coil. _ .... I Electrolytic Rectifier. —Device _ lor ' changing alternating current ixito i direct current by means of a solution or electrolyte and suitable electrodes. Electro-motive Force. Tho force which causes au electric current to How or tend to flow from one point to another due to a difference of potential 1 between these points. It is usually abbreviated to E.M.F. i Electron.—This was the name given ' long ago to the supposed atom of electricity by Dr Johnstone Stoney, in anticipation of its future isolation and 1 complete discovery. The real nature of ! the electron is not yet known, but it is I believed to be a definite and peculiar modification of the other of space. Electron Relay.—This is a term sometimes used for a three electrode valve. Electrostatic Induction. arising from static. Element. —Word used in several senses. In a primary cell the two electrodes are often known as the elements. Emanation.—ln radio a term synonymous with emission, to denote the throwing off of electrons from a body. E.M.U.—This is the standard abbreviation for electro-magnetic_ units, based on tho definition of the unit magnetic polo. Energy.—Capacity to do work. Energy is something that is given to a body by doing work upon it, as when a book is raised and placed upon a bookshelf, or a wheel spun round. _ The energy is given out when the body itself performs work. Ether.—Space is not really empty, hut filled with an unknown medium, capable of transmitting gravitational force. It was Newton who called this hypothetical medium “ether.” * Fading.—Fading is the name given to a phenomenon evidenced by tho variation of the strength of radio telegraphic or telcphojiic signals. It has long been known that the strength of a signal is not the same at all hours of the day and night, and that at certain periods tho variation of strength si greater than at others. A possible explanation of lading lias been put forward by Dr Eccles. His theory is that, owing to the degree of ionisation being duo to tho intensity of the sunlight, a surface of equal ionisation will he near the earth where tho sun is on the meridian, rising away from the earth where tho sun is rising or settting. Thus a circular hand is formed round the globe by the regions which are changing from tho night level to the dav level. Tho twilight band moves with the sun, and when over the transmitting station it acts as a partial reflector, and produces the increase m signal strength. When tire hand is moved to the position between tho sending and receiving stations this causes a decrease in signal strength, duo possibly to electrical disturbances. Fahrenheit. —Name of a thermometer invented bv G. I). Fahrenheit. Farad.— Unit of electrical capacity. (To bo continued.) THE INDIAN STATIONS. Tho Indian Broadcasting Company has two stations, one of which, 7BY, Bombay, was officially opened on July 23 (says an exchange). The wave length is 357.1 metres. The other station, 7CA, Calcutta, will bo opened this month. The wave length will be 370.4 metres. Tho power of tho stations is apparently about equal to that of 2LO, London—3 kilowatts in tho aerial. A special programme advisory board of twelve men has been formed in India. For tho first few months tho programmes will be restricted to four hours’ transmission daily and the times (Indian time) are as follows:—Sunday, II a.m. to noon and 6.30 to 10 p.m.; Monday, Wednesday, and Friday, 11.30 a.m. to noon and 7.45 to 10.30 p.m.; Tuesday and Thursday, 3.30 to 4.30 p.m. and 8 to 11.30 p.m.; Saturday, 3.30 to 4 p.m. and 8.15 to 11.30 p.m. Special European programmes will be broadcast on Mondays, Wednesdays, and Fridays. New Zealand time is six hours ahead of Indian time, so that 8 p.m. in India corresponds to 2 a.m. in New Zealand.

COMPETITIONS FROM 4YA. Big Brother Bill intends to run four competitions from 4YA between now and Christmas. He will conduct these competitions in conjunction with the children’s sessions. This month he is asking everyone to write a limerick on radio and post it to him. The limericks will he read over the wireless, and each one numbered, and those listening-in will bo asked to vote. The one receiving the most votes will be awarded a prize of ss. AU entries must bo in by October 18. As an example Big Brother Bill w r rote tho following limerick : A clever young man in St. Clair With a crystal set went on the air, Ho got London and China, Spain and Argentina, But his friends say ho isn’t all there The other competitions will be a laughing, mouth organ, and whistling competitions respectively. All you are asked to do in the laughing competition is to go before the microphone at 4YA and laugh heartily. There will also be a prize for the winner of the laughing competition. The two musical competitions will be run on the sumo lines as the others. Other big things are promised in the future by Big Brother Bill. SLO’S SHORT WAVE TRANSMITTER. The following is a description of 3LO’s short wave transmitter:—The output from tho studio is applied through a lino amplifier and sub-modu-lator unit to tho grids of the modulator proper, which in turn is coupled to the plate of tho special short-wave oscillating valves. These valves are of unique design, and are enclosed in metal screens in order to distribute tho high-frequency losses over tho whole of the glass envelope, and thus reduce the risk of puncture at tho high potentials used. The oscillator is worked on the amplifying drive system through the stages of magnification—modulation taking place on the last stage. Tho output from this is then fed through a specially-designed coupling circuit through a lecher feed to the distant aerial. Tho lecher lines Consist of two highly-insulated, tightly-stretched wires supported on miniature telegraph poles. The energy from tho transmitter is fed mto tho base of the aerial system by means of a special coupling. Steps are taken to prevent radiation from the lecher system .and to eliminate reflection so as to ensure the maximum transfer of energy from tho oscillating apparatus to the aerial. The advantages of this system are that the aerial may bo kept free from interference likely to be caused by conflicting electric fields in and around tho actual generating apparatus, buildings, and other factors likely to cause absorption duo to the enormous intensity of the electro-magnetic fields set up at frequencies of the magnitude of those to bo used for these tests. _ The various units of tho transmitting equipment are electrically screened from cacli other, and tho frames and panels made of brass. Tho circuits are so balanced that all fields induced in the frames are neutralised. All highfrequency portions of the equipment are supported on plate-glass strips to eliminate dielectric losses. . The potential on the plates of the main transmitting valves will be 8,000 volts, supplied by a specially constructed three-phase double wave rectifier and associated smoothing unit. With this equipment Melbourne will have the most modern and most powerful short-wave broadcasting station in the Southern Hemisphere, which should be capabi* of being heard in any part of the world. All the apparatus was designed and built in Australia by Amalgamated Wireless (Australasia), Ltd. HISTORY OF 4QG. Contained in the annual report of the Queensland radio service is a brief outline of tho history of broadcasting in that State. Towards the latter cud of 1934 the Government decided to establish broadcasting as a public utility in the northern portion of Australia. In the southern States private companies had established stations, but it was decided to take steps which would result in Queensland’s station being controlled by the Government, and conducted for service rather than for profit. Early in 1925 the State Government secured the only A grade license available for Queensland under the Commonwealth wireless regulations, and immediately set about constructing a high-power broadcasting station in Brisbane.

Tho work of constructing the station was carried out in a thorough manner, and tho building took a considerable time to erect. The Government temporarily erected in July, 1925, a small 500-watt station, fitted a temporary studio, and started a temporary service. This served to introduce radio to the public. The small station was of Jow power, and its range was limited. It served its purpose, however, and provided a moderately good service while tho big station was being erected. Early in 1926 the main plant was completed, and a testing period was carried out. In April of that year the station was quite completed, and a full broadcasting service on high power was inaugurated. Since that date the broadcasting movement lias gone ahead very steadily in Queensland. Tlia capital cost incurred iu connection with the establishment of 4QG (including tho temporary plant) was £33,552. Interest at the rate of 5‘ s per cent, per annum is charged on this amount.

HERE AND THERE. IYA, Auckland is reported to be coming in muck louder of late. A good story comes from 2BL. An old gentleman walked into the Sydney station recently, and remarked that he hud just bought a valve set. “ I can’t blow out the valves, and I’ve tried over and over again,” he said. Uncle George, at 2BL, was of the opinion that the old gentleman was lucky, as he knew of beginners who blew out their valves without trying. The visitor furthero stated that he had blown and blown at them, and they would not go out. So, of course. Uncle George told him just what to do. Kenneth Irapett, a young New Zealand baritone, who has been a popular Vocalist on the 3LO programme, intends to go to Italy shortly to study voice production He will give a series of recitals from 3LO before his departure. . 4YA has been giving us a pretty good {service recently, although few eosm to realise it. What do you think of 3YA’s new good-night call? Reception of the Australians lately lias not been of the best, what with static, and fading and such like things. Howlers this week have not been quite so bad as previously, although there has been a fair swag of them Hekintr around after ID at, night.

“ Henry" will be pleased to answer any questions through this column relating to the fascinating hobby. Each correspondent must sign his name and address (not necessarily for publication). Newsy items will be welcomed.

TARANAKI RADIO SOCIETY. The North Taranaki Society seems to be doing some good in that district. Already the Broadcasting Company has sent its officials to investigate receiving conditions in Taranaki, and as a result the society is co-operating with the company in a series of tests intended to improve the efficiency of 2YA as far as North Taranaki is concerned. Other activities for the benefit of radio are claiming tho attention of the society, and tho membership is reported to be steadily increasing. “ WELL DONE, LONDON.” The following was taken from a London paper of March 12, 1924, following special tests between England and America. A distanct reception is all the rage now, tho cutting should prove of interest:— “The broadcasting of dance music from the Savoy Hotel ballroom in London to America early this morning was a great success. Cables of congratulation on excellent results have been, received at hotel from Brooklyn, Connecticut, Philadelphia, Washington, and Montreal. Mr Dylan, Mayor of New York, cabled to tho Savoy Orpheans Band: ‘ You have accomplished very great result. Well done, Loudon.’ ‘‘ At 1.30 a.m. Senatoro Marconi broadcast his greetings to America from Savoy ballroom, and said he hoped that in the future the residts achieved this morning, excellent, though they were, would be surpassed. “Many men and women who were dancing in the ballroom at tho Savoy Hotel m London at 1 o’clock this morning were tlixillcd by a voice which said suddenly and sharply: “‘Hollo! Hello; America. All stations of the British Broadcasting Company calling you.’ “ A pause, and then a voice said again quickly: “ Stand by to receive tho Savoy Orpheans Band. “Another slight pause, and the Savoy OrpJieans Band played a jaunty fox trot. “ Two large microphones were suspended from the ceiling of the ballroom through which sounds of music were spirited to the United States. “Americans in London made it a gala night. Familiar British airs wore played, and finally ‘ Tho Star-spangled Banner’ and ‘Cod Savo tho King’ were broadcast. As the last notes died away one of the Americans said: ‘ Let’s give the old folk at home a clap,’ and a wave of clapping was ‘ sent over.’ “Before the concentrated broadcasting began, a cable was received at tho Savoy Hotel, stating that at 11.45 p.m. Lomfon time ((3.47 p.m. New York time) ‘1 Love You,’ played by_ the Savoy Orpheans Band had been picked up at Bronx, Now York.” This was indeed a great feat in 1924. looking-in. There arc still many references to the supposed early advent of “looking-in.” And tho hazard, therefore, of disappointment to an expectant public develops apace. It would be a great pity if promises, more or less lightly made, regarding the introduction of television, or radiovision as it should more properly he called in its relation to broadcasting, were not to be fulfilled. Damage nas been done already to young industries that appeal to popular imagination by ovor-cuthusiastic statements as to tlie efficiency of the system concerned (writes “Kay Dio,’ from oLOj. Not infrequently these statements have been made by interested persons who have some financial expectations to realise by early exploitation in the commercial field. Reasonable publicity and propaganda cannot bo objected to in developing a now industry or system, but promises should not bo made that cannot readily bo fulfilled.

The scientists and research workers who arc giving their time and. energies to the development of a workable system of radiovision. arc not the offenders in this regard. They havo_ not overstated the immediate possibilities of their systems; their statements have been confined to an explanation of what has been done, and in some cases the lines ol advance have been indicated. It has been the more or Jess irresponsible writers in the technical Press who started, and have continued, the undeserved publicity concerning the early adoption of various systems. Although the basic principles of transmitting photographs or images were known us far oack as filty years ago, it has only been during the past two or three years that useful progress lias been made. The principal explanation is the great concentration of research work on radio phenomena and speech transmission in particular. As in the case of broadcasting the modern Aladdin’s Lamp, the valve, has bad a lot to do with it.

Both in Europe and America great work has been done by inventors and experimenters. While there aro no marked differences in the fundamental principles of the various systems, there aro important variations iu details. The transmission of “ still ” photos is comparatively well developed; the work of the research engineers of tho Telcfunken Company in Germany, and of the Radio Corporation ol America standing out prominently. In England the work of Baird has been most successful; in fact, his results are specially meritorious when one considers the handicaps he is under as regards facilities and financial assistance, as compared with the large companies. The transmission and reception of moving pictures is not as simple as the talking pictures as displayed in “ the movies” would lend, one to believe. The application of radiovision to a broadcasting station like 3LO Melbourne would involve serious changes. The frequency band necessary for transmission is much higher than the band used for broadcast, and there is no chance at present of transmitting any imago that is not close up to the “electric eye ” of the sending equipment._ It is dear, therefore, that we must not expect to have any reasonable system of “ looking-in ” for some time to come. GHOSTLY. The Adelaide station, SCL, has been responsible lately for the broadcasting of a number of stunts, but it is said that the latest is the best of them all. By well thought out dialogue tho impression was given that a prominent scientist, for a wager, had consented to spend an evening in a haunted house. Tho happenings that followed the visit of the scientist were of a most unusual nature. With great gusto the visit to the house of long past occupants was described, arid had the effect of turning many a listener almost into a block of ice.

4QG’S ANNUAL REPOUT. “ During the last twelve months the broadcasting movement in the State of Queensland has developed considerably, and the year has also been sncces.slul from, a financial point of view, the operation of station 4QG having resulted iu a moderate profit.” Thus i states the annual report of the Quccnsj land radio service. Continuing the report rends: “The I year 1926-27 really represents the first 'period during which the station Mis • been in full and complete operation. With the commencement _ of the year quite a largo number of people had installed receiving sets, the first feeling of novelty had worn oft', and tho operations of the station were regarded by listeners as being tho actual provision of a real service. Every effort was made during the year to increase the scope of the transmissions, and to include in tho broadcasts items and matter which would prove of value to tho whole community. The license figures may ho regarded as a most accurate indication as to wlietrer broadcasting is progressing or not. In 1926 there were 8,373 licensed listeners in Queensland, and this year the number had increased to 23,163 by Juno 30. Since broadcasting was established in Queensland no less than 1,354 different artists have appeared on 4QG’s programme. This figure has been arrived at'not by counting each artist who has appeared, hut by regarding a hand as one artist, a choir as one artist, a duet as one artist, and so on. These artists have contributed no less than 17,611 items. An analysis of the foregoing figures shows that each artist lias contributed an average of thirteen items, and the average appearance of each artist works out at one every eight week* Rlnco *ts inception <»QG has done its utmost to enable listeners in all parts of the State to hear the voices of great orators of prominent statesmen and of notable visitors. “ In order to give the public some idea of the possibilities of radio, 4QG lias carried out a number of novelty transmissions. Speech has been transmitted by a diver from the bottom of Moreton Bay, concerts have been broadcast from coal mines, and so on. Also quite a number of “stunt” transmissions have been arranged from E i studio. Advantage lias been taken to install microphones in various places, and broadcast important functions and happenings. Tho visit of tho Duke and

of, and was wirelessed whenever possible, lines being laid to the various points at which functions were held, and descriptions relayed. The broadcasting of church services has become very popular. The station is linked up with fourteen churches in Brisbane, and allots dates for broadcasting according to the percentages of religion as set out jin the Registrar-General’s figures. “ Bedtime stories constitute one ol the most popular, if not the most popular, broadcasts from the station, and ore listened to with interest by as many adults ns children. The policy of the station is to make them a« varied as possible, and it does this bv transmitting children’s entertainments by different characters on different nights. The services of a number of the storytellers are given voluntarily. “During the year the station was live first in the world to have the honor of broadcasting a complete concert by Dame Nellie Melba. The transmission was a complete success, and drew favorable comment from all parts of Australia. “The mail received at 40G is heavy, and from it the staff gains some impression of the views of listeners, in certain portions of everv State there exist areas in which the reception from nearby stations is poor at night time. They are very small, 'however, and. apart from certain districts, comments from listeners seem to indicate that the transmissions arc well received. Rr>iports from New Zealand and the Pacific Island have been numerous. “The science , of radio has greatly advanced, and it, has been possible during the year to receive London nnrt Paris programmes direct in Brisbane and relay them from 4QG. “The operations at. 4QG during 1926-27 resulted in a profit of £5,334 14s 6d.” RELAYS OF PCJJ. 3LO announces that it is hopeful of introducing regular relays of PCJJ, Eindhoven, Holland. In experimenting it has been found that in the early evening in Australia the conditions seem more favorable for relaying purposes. Musical items from PCJJ transmitted just when day was dawning and received in Australia as night was falling came through admirably during recent tests. Those who.do not possess short-wave sets will perhaps be able to hear the Dutch station very 3T-Q— —————————•

RADIO LICENSES. In a recent Police Court case in Auckland a listener was charged wild failing to renew a radio license. In giving evidence, the accused said that parts of his set had been hanging up since February last. The sct_ was installed at a summer cottage, in which he had not been living since April. Export evidence given was t« F*'' 1 effect that the set, as produced ill court, could lie connected up within five minutes. I'o comply with the regulations for dismantling a set, he considered it, would he necessary for an owner to take the set out of tl;e house. It was stated that the set had been dismantled as the word “ Dismantled ’* was defined in the standard dictionaries. A letter from a Wellington agent stated that he had interviewed the officer who deals with the licenses under the Secretary of the Post Office. He had been informed there was a difference of opinion between magistrates as to the extent of dismantling. To right the matter there was an amending Bill before Parliament altering the Act to read “ totally dismantled.” The magistrate was of the opinion that tho “ totally ” would not make any difference. In his opinion the set was hot dismantled in the meaning of the Act. A line of Is was imposed in order to allow of an appeal. Let this case serve as » haaoA