NOTES AND COMMENTS

Radio Record, Volume I, Issue 36, 23 March 1928, Page 6

NOTES AND COMMENTS

{By

Switch

_. A course in radio announcing is open to students at the University of South Dakota, U.S/A., and a dozen men students are enrolled in the first class to be organised. | _. & proposed by-law at Little Rock, Arkansas, U.S.A., would declare a public nuisance any electrical equipment. radiating waves detrimental to radio reception. The Bill, twice read before Council, has been approved by Mayor Charles E. Moyer, himself a radio enthusiast, and by the lighting and pub- | lic utilities committee. | Sulphate begins to form when a battery is in a run-down state. "Switch," having a home-charger, gives" his wet "A" and "B" batteries a charge every two or three days to keep them up to full strength. He gets, on an average, fourteen stations in New Zealand and Australia every night on the Joudspeaker, using a four-valve Brown-ing-Drake circuit. | In the past three years the radio in‘dustry has risen from the 34th to the 12th in the big manufacturing business of the United States. A valve will become inoperative if ‘the filaments are subjected to continuous overheating. Most of the valves now in comimon use are of the thoriat-ed-tungsten type. ‘This type depends mpon a surface layer of thorium oxide for its electronic emission, and this active layer is automatically deposited or formed on the filament when the valve is operated at a certain temperature, Never turn on any valve brighter than necessary. The San Francisco "Examiner" gays: -‘Radio clubs throughout the country have dwindled somewhat, because the members cannot find time to attend the meetings. During the winter they spend all their time DXing in an effort to outdo their fellow club members." This seems to be the main source of trouble with the radio clubs in New Zealand. The average new radio owner is inclined to return his set to his dealer because he cannot tune-in China the first night the radio.is installed. ‘This. type takes everything for granted, and. never considers how much time and | effort is wasted by the one who accom_plishes this sort of a feat. Every radio fan in Paris gets a chance to take the place of the speaker at a local transmitting station, and share -his glories for a few brief mioments. © attain his ambition he has to be the first to ring up the transmitting station on the telephone and give the answer to a riddle. It is then his turn to proceed to the station next evening and from the speaker’s stand ask al} the listeners-in another. An outdoor aerial must not touch anything unless it is an excellent insulator, and the fewer points it touches, even though they are insulators, the better the aerial insulation and the more energy comes to the receiving set. ff for any reason a storage (wet) "A" battery of the lead plate type is to be stowed away for some time it should be fully charged and the electrolyte removed, The electrolyte may later be poured in, the battery charged and put into operation. The French housewife’s fight against unsightly loudspeakers is causing imakers to disguise them in all sorts of artistic ways. The sounds of the tadio set issue from a small marble fountain in a corner of the room in one radio set put cn the market in France. All dues in the Spokane Radio Listeners’ Assnciation at Spokane, Washington, U.S.A., have been abolished. Hereafter any radio listener in Spokane may become an association member by registering his name with the organisation. Some listeners seem to want a bonus for joining a New ZeaJand radio club! Yhe aerial should uever be torgotteu, as it is the source of many difficulties. It must not run parallel to tugh tension wires. It should be well insulated and the lead in free from contact with any grounded object. The municipal telephone management of Rotterdam, Holland, is planning the distribution of radio programmes over the telephone to subscribers. ‘lhe system lias been in use in The Hague for the past year, and is reported to have proven popular. The installation expense is said to be small and a moderate annual fee is also charged. Does ether transmit waves? In his address before the delegates to the international radio telegraph conyention attending the dinner in honour of Marconi, David Sarnoff, vice-presi-dent of the Radio Corporation of America, made the following observations on the behaviour of radio waves: ~-"Professor Einstein tells that ‘ether’ does not transmit light; it must follow therefore that ‘ether’ does not transmit electromagnetic waves, If this view is correct, it completely removes the invisible track which our first theories erected to speed the radio signa) throngh space. It becomes. no longer correct then to refer to ‘ether waves’ or to ‘ether channels’ in radio transmission, Under this new theory we must refer to them as ‘space channels.’ |

Relatively few people in Australia and New Zealand have heard a carillon, although some who listen to the radio: stations have heard broadcasts of some of the world’s finest carillons, notably those in Holland and Canada. The University of Sydney will soon be provided with a carillon, installed as a memorial to the institution’s war heroes, and the Sydney broadcasting station, 2FC, is planning to broadcast the instrument. The carillon on a fine night is likely to be heard for a distance of a mile or two from ‘ts tower at the university, but with the aid of radio it will be heard throughout New South Wales, in most parts of Australia, and all over New Zealand. A carillon will also shortly be installed at Bathurst, N.S.W., and station 21C will probably broadcast it also. Long-wave daylight radio signals from distant stations and from those only, 200 or 300 miles away were stronger in 1927, when the eleven-year sun-spot cycle was near its maximum, than in 1923, when it was at its minimum, according to conclusions of Dr, L. We Austin and Miss I. J. Wymore, of the | United States Government Bureau of Standards, who advanced this idea rerently as ‘fa reasonable certainty,"’? A commercial radio expert, G. W. Pick~ ard, has shown, on the other hand, that at night in the broadcasting range signals grow weaker when the number of sun spots inereases, the Department of Commerce further declared, and added: "Hence it appears that the effect of solar activity on signals is reversed when day gives place to night." This corresponds, it was stated, to the conclusions of the engineers of the Bell laboratories, that magnetic storms, which are known to be connected with sun spots, weaken medium and longwave signals at night, and slightly, strengthen them in the daytime.

The chief drawback, apart from atmospheric phenomena, to world broadcasting is the differences im time. Even this difficulty may now be overcome, however, by a recent invention. This is nothing more or less than the actual electric recording of the sonnd waves of programmes on coils of metal tape. ‘The tecording, therefore, of English, American, and foreign | programmes in this manner, and their rebroadcasting at times suitable to Australia, New Zealand, Canada, and the rest of the colonies, would mean petfect reception and exchange of intercolonial and world programmes at all; and any tims. Atmospheric conditions for radio reception on the Atlantic Ocean are just} about perfect in midwinter, according to K. \. Allardyce Arnott, managing director of the Freed-Kisemann Radio, Ltd., of London, who arrived at New York from London on the American ( Banker recently. Mr. Arnott said that this was his sixth trip across the Atlantic, and that on each preceding journey he had experimented with recepdion, but that the results were in no way comparable with those during the last crossing. ‘We left London on December 30," Mr. Arnott said. "During the entire yoyage we were never out of touch with land day or night. The Daventry station, 5XX, came in strong, until we were off the Bauks of Newfoundland. We heard the New Year’s service from the York Cathedral and the ringing of the chimes." 9 Mr.. Arnott used an American-made — sixvalve set during the experiment, and ranged up and down the entire broadeasting band between 200 end 550 metres without any appreciable ditterence in reception. The United States Navy Deportinent

has reported that Jugyh power valve | transmitters cost more than are tratisnutters of the same power, and cites the case of the transmitter installed at San Dicgo during the latter part of 1926. The Gericral Ilectric Company, whieh installed the plant, had to keep two engineers at the station cudeavouring to overcome dcfects in the appatatus for more than a year, and had to replace approximately £5000 worth for valves during the time that the installation was undcr test and before the Nayy Department took it over. This indicates, 1o some extent, the difficulties nict in the construction of tratismitters raling near 100,000 watts. With the are transmitter none of this trouble is experienced, but it appears as though the efficient arcs must be scrapped as obsolete unless the interference probJem is overcome, ‘ In case at any time your ‘‘C’’ battery leads should accidentally have their polarity reversed you will recogmise the fact by the extreme faintness of signals, or in some cases their entire absence. An exhausted "C’"’ bat-. tery will also cause all sorts of trouble although owing to the very — slight drain on this unit a ‘C’’ battery will outlast two or three sets of"Bp" batteries, and does uot often cause trouble. Nevertheless, if your set won't go, or if it behaves in an unruly manner, do not overlook this point. Test with a voltmeter, and make certain the reading is not less than 3 volts for a 44 volt battery. This is the extreme limit. Should it read lower throw it out and substitute a new battery. tu traciug the cause of noise in a re-

| ) | ) ) | | ) ) eeiving set it is advisable to conimence by testing the high-tension battery ("BY battery) either by trying it on another set or by trying another battery {known to be O.K. ou oue’s Own set), or by a voltmeter. When the insulation of the telephone winding has deteriorated, as it will in high-resist-ance telephones used in valve circuits, loud cracking noises result. Telephones may be tested on another set or by comparison with another pair on one’s own set. The grid-leak is often 1a source of noise. Once the trouble has been traced to this it is easily remedied. A Melbourne writer says: "It is not too much to say that not only are we nearing perfection in broadcasting and its reception, but we stand on the threshold of an entirely new era. 1928 will see the establishment of a regular setvice of Impire and world broadcasting, and this will be made feasible entirely through the medium of super-power on the ulira-short waves. Hitherto we have been accustomed to regard reception of European and American statious as exceptional. Before the end of the year we shall hear broadcasting from ail parts of the world as easily and regularly as we are now accustomed to heating our own Australian stations. This is no idle forecast, but it is based on what we alrtady know, and on what has been done by our experimenters, amateur and official, and particularly ott the good work done by that now famous Dutch station, PCJJ, Hindhoven, Holland, notably in the re-broadcasting of British, French, and German programmes. ‘These have been receive easily and regularly in Australia for at least six months on PCJJ’s wave of 60.2 metres," The British short-wave amateur, Mr, Gerald Marcuse, is now broadcasting regularly as follows :-Sundays: 6 a.m.8 am; 4 p.m-§ p.m; and 6 p.m.8 pm. Wednesdays and Fridays at iL p.m.-L asm, (Thursday and Saturday). On ‘Tuesdays he is giving a broadcast at 6 a.m. All the times given are Greenwich mean time, Mr, =| Marcuse’s call is 2NM, and he oner-

Australian school teachers and students iu the country will be catered for by a special series of educational talks to be broadcast from 8L0, Melbourne. The series will begin ou Thursday afternoon, February 23, and will be given from 3 till 4 o’clock, The feature was introduced last year, and proved highly interesting. The talks will cover such subjects as literature, languages, travel, and music. One stage of radio frequency ahead of a detector makes a tremendous difference in long-distance reception. The effectiveness of radio-irequency ampJsiication is made apparent when valve detectors are -nsed, as the sensitiveness of these devices is proportional to the square of the voltage applied to them. In other words, if the incoming signal 1s amplified to double its normal voltage, the strength of signal in the plate circuit of the detector valve will be four times as great as before. An Australian radio scribe says: ‘‘The method adopted in all countries of giving a call sign to the station is one that ‘just happened,’ and there is no particular warrant for its use. It is questionable if it is the. best one for the purpose. In Russia some of the big stations have names such as the Popoff station at Leningrad, named after Popoff, who is perhaps as much entitled to be called one of the real pioneers of radio as anybody. In America some stations, in addition to their authorised call signs, have auxiliary titles. Kor example, a well-known station in St. Louis announces itself as ‘the Voice of St. Louis.’ Maybe it would be useful for us to consider adopting some such system. It would give to the station 4 more intimate of ‘personal’ touch that wonld have its psychological effect on listeners. Of course, the practice could be overdone, and auny-innovation needs to je carefully pre-considered." As an argument in fayour of establishing relay stations in Australia, a Melboutne writer says: ‘‘Distance is the main obstacle in the way of an efficient broadcasting service for the whole of Australia. Distance and huge stretches of sparsely populated country oe oe eo t

ame a VaTTICr tO ONE CsteDiiniwwe»nie Ul big broadcasting stations situated closely together as they are in Kurope and America. The area of Australia is greater than that of Europe. The distance from Melbourne to Perth is equal to that from Greece to Portugal, whilst a line drawn from Athens to Scotland would only reach from Melbourne to the far north of Australia. "The existing broadcasting stations in Australia are limited by Government regulations. They are established in the six capital cities, but as they are separated by many hundreds of miles, and are situated along the southern and eastern fringe of the great continent, an idea can be formed of the task of supplying an efficient service for the whole of the Commonwealth. Listeners in distant parts certainly tune in regularly to the big station-3LO, Melbournebut naturally reception at times is marred by disturbing influences." Everyone is talking alout the ~ remarkable reception of the Australian stations on Thursday night, February 9. From 11.30 p.m. onwards the Aussies commenced to pound in, and by 12.15 am. on Friday even 5CL, Adelaide, was giving us good loudspeaker volume. The writer picked up a long-) distance station a few metres above 3LO, Melbourne, at 1 am. A_ child was reciting in English, and was being prompted by a woman. At the conclusion there was prolonged applause. 40G, Brisbane, is now running a gramophone session from 10 p.m. till 10.30 p.m. once a week. The director

has issned the following notice: "There are numbers of people who are owners of gramophones and other talking machines, and 40G proposes to devote a short session once per week for a period of a month to these people. ‘The records used will be specially selected for broadcasting purposes. The inclusion of this session is in the nature of an experiment, and listeners who are interested are particularly requested to listen to the announcement which will be made prior to the transmission, Comments and suggestions regarding the session are invited." The British Broadcasting Company cabled to 8L0, Melbourne, under date January 30, as follows:-‘'Reception of 38LO on 82 metres good Jast nightlittle fading-75 per cent. intelligibility.’ To achieve such pronounced success that 75 per cent. of a programme of music and speech extending over two hours is inteligible, marks a distinct advance in world broadcasting, A Press telegram received by the Australian daily papers stated that Gerald Marcuse, the celebrated English experimenter, at the conclusion of 3L0’s programme on January 30 said enthusiastically: "It was easily the most wonderful short-wave transmission ever heard from Australia. ‘The programme was audible distinctly throughout.’? Mr. Marcuse for most of the time was able to employ a loudspeaker, It was so distinct that the announcer could be heard taking his breath during the reading of the news. A membership increase of 65 per cent, is shown in the annual report of the U.S.A. Institute of Engineers. The organisation, founded in 1912 for the benefit of the radio engineer and his co-workers, has increased in size, until it has 4852 persons on its rolls. In cluded are radio authorities in all quarters of the world.

A radio loudspeaker capable of broadcasting sound up to 1} miles, and yet retain the musical quality of the tune rendered, was recently demonstrated at the Royal Institute of Technology in Stockholm. The speaker can be mount. ed on a truck and transported around to be nsed at fairs, mass meetings, etc. The novelty is called the ‘Riesenblatthaller,"? | The drum is the most difficult instrument to reproduce over the micro- | phone. Iixcessive voltage or defective insulation will cause condensers to break

a weet em we . a Germany is said to be the most pro« gressive Ruropean nation in the advancement of radio. There ig a chain of powerful stations operating in the ten or more leading cities, Canada has seventy-five broadcasting stations. " There are 1,252,126 farms in the United States equipped with receiving. sets. : Upwards of 150 radio stations in the’ United States broadcast daily weather, reports. . Ten o'clock curfew for radio broadcasting is the newest plan in Italy in an effort to stamp ont importe-