NEWS AND NOTES

Radio Record, Volume I, Issue 24, 30 December 1927, Page 8

NEWS AND NOTES

(By

Switch

Here, you married men, listen to this;.it’s worth while trying. A crying baby will generally be pacified if the headphones are placed on its ears it broadcasting is beimg received. ‘Ihe music that tames the savage breast can do the same with a howling kid. ‘Try it Radio valves that have come loose from their bases may be repaired in a few minutes’ time with a small quantity of commercial alcohol. At the point where the valve enters the base pour a few drops of alcoho}J. Allow the valve to stand for a moment until the alcohol moistens the cement, then press the bulb firmly into its base and set it aside for five or ten minutes. Upon examination it will be found that the cement has hardened and the valve is gs good as new. , Most men are interested in science, but it is almost impossible to grasp scientific conceptions without having some scientific experience. The fact that so few men maintain chemical laboratories, astronomical observatories, botanical gardens, or zoological collections indicates that most forms of scientine research are beyond the reach of the multitude. Radio, one of the newest sciences, is basically as old as any; it is the only one that is wide open to rich and poor, sovnd and crippled, educated and uuschooled. . Radiovision will make its debut in time for the people of North America and Western Europe to view, as well as listen to, the inauguration ceremonies of the next President of the United States, is the prophecy made by H. M. Shaw, ‘The preliminary steps to clarify the patent situation has made remarkable progress, as shown by reputable manufacturers of radio apparatus, who haye acknowledged patent responsibilities and rights.

0. \/ rt A young American inventor, D. D. Knowles, has perfected a grid-glow reJay valve which is regarded as the inost sensitive current-controlling device ever developed, as it functions on a thousand-millionth of a watt. It is set in operation by the light of a match, or the approach of the human hand or a drop of water. "This is ‘Ilenry’ broadeasting,’’? To hear a station open its nightly programme that way would be the reguJar thing if some radio fans had their way (says a Washington, U.S,A., writer), ‘They can see no reason for continuitig the apparently meaningless call letter system, but it is not likely to be changed. Many call letters stand for names of station owners or mottoes. In some cases mottoes have been adopted in accordance with the letters. Examples are "WHT," Chicago, for Mayor William Hale ‘Thompsons; "KGW," Portland, Ore., for "Keep Growing Wiser," and "GTT," San Franciseo, for "Glad ‘Sidings ‘fabernacle.’"’ Although many devices have been announced, alleged to discover the presence of metallic ore under the ground by magnetic or clectro-mag-netic means, until quite recently very little practical use has been made of fhaem. When ground currents of radio frequency are transmitted from one point to another, the strength of the received impulse is dependent upon the power of the transmitter, the sensitivity of the receiver, the distance, and the conductivity of the soil, ‘The presence of metallic ores exhibits itself by an unusually strong signal for the transmitting power and distance involved, Tlowever, no means has yet heen developed for identifying the kind of metal involved, so that the principal value of such observations has heen rather the elimination of unpromising ground than the identification of yaluable mineral ores.

An American authority says an aerial from 40 to 50 feet high is the best for escaping great barrages of static. President Coolidge, in his address before the: International Radio Conference at Washington, said: "This conference recognises that the radio has become a great influence in the world. Like every invention which increases the power of man, it may. be used for good or for evil. It can serve the cause of understanding and friendship among people and among nations, or it can be used to create ‘ll will and dissension. The world will not be benefited by this increase in the scope of its powér unless there is a corresponding increase in moral development. Your main object will be to raise this great industry into the realm of beneficient public service.’? Lack of sensitivity and volume in a receiver cati often be traced to poor contact between the socket contact springs and the prongs of the valve. The exceedingly feeble currents passing through the socket must meet with a mivinsum of resistance, and in this respect, perfect contact hetween the prongs and socket is an absolute necessitv. A liberal application of a fine grade. of sandpaner on the yalve prongs will quickly remove any of the corrosion and high spots which make fer a poor contact. It is advisable to clean the prongs at regular intervals.

Excessive voltage or defective insulation will cause condensers to break dow11. A receiving or transmitting’ valve that will not oscillate any more can be made to serve as a rectifier tube as long as the plate or grid are not shorted to the filament. ‘The socket springs con-| necting to the grid and plate of the tube should be wired together. so that. the tube will carry more current, In the United States some schools encourage pupils to build broadcast rr ceivers for home use. Some have workshops where the young set-builders work under the supervision of manualtraining teachers. In one State, in a single year, school officials reported that more than 4000 receivers were built by pupils, and it is believed that as many more were built, but not reported.

One of the silent men in Joe Aronsows Synco-Symphonists at 8LU, Melbourne, is Andrew Robertson, a Scotchman, but, typical of his race, when he does make a noise, it is indeed "some noise," not on the bagpipes, but the sousaphone, the big instrument which booms out the deep bass notes with such bcautiful mellowness so noticeable in the syneopations of Joe Araquson’s Symphonists. In Japan the entire cost of broadcasting, including operating expenses, salaries, and artists’ fees, is disbursed by the license fees collected from the subscribers, who pay a monthly fee to the local broadcasting station of one yen, or 2s., and an additiotial yearly fee of one yen, or Ys., to the Govetnmeiit. . It is frequently found that, for a small room, a 201A-type valve in the last audio stage, will give sufficient vol. ume, without overloading or rushing the valve; but, for a fair-sized room, a 112 or 171-type power valve should certainly be used in the last stage of audio-fre-quency amplification. If you select a 112-type power valve you have increased by four times the undistorted power output available for actuating the londspeaker. But if you use instead a 171type power valve you will increase the undistorted power output of your last) stage, with respect to the toudspeaker, ‘a tactor of fourteen, A very pleasing satin effect may be given ally panel by observing the following procedure. After the panel lias been drilled, lay it on a piece of newspaper which has been placed on a flat surface. Then with a fine grade of sandpaper, No. 0 or 00, sand the surface of the panel aiong its length, applying at the same time a liberal quattity of iubricating oil. Do not limit the strokes in sanding to less than the total length of the panel, or the satin effect will not be uniform. After the total surface has been covered, remove the surplus oil with a soft cloth, wash the surface with gasoline or a similar cleaning compound, and polish with a dry cloth. Under no circumstances use a coarse grade of satidpaper, sitice its application on. the highly finished surface of the panel will gouge out deep scratches, which are virtuatly impossible to remove. The Melbourne "Ljistener-in’’? says: — ‘Mr. James D, Seymour, who has been engaged for a season by 8DB fa Melbourne "B’" class broadcast station) to sing popular and standard songs, is a newcomer to Melbourne. THe hails from New Zealand, a country that has sent us many good vocalists. Mr. Seytour is the possessor of a resonant bass-baritone voice of pleasing quality, and was closely connected witl various musical organisations in Dutiedin, notably the Dunedin Choral Society, Burns Cinb, Gaclic Society, and the Dunedin Glee Cluh, to which latter he was hass Soloist for a umber of years, and of which he is a foundation mener."

The experimenter is not always the proud possessor of a power valve, and yet he has offen desired one, A reasonable substitute for a power valve in the last stage of audio amplification can be found in connecting up twe ordinary 201-A type valves, with their plate and grid elements in parallel. In other words, an extra 201-A valve is connected to the plate and grid terminals of the last audio frequency amplifying valve. The filament of the extra valye is connected to the "A" »battery in the regular manner through | a ballast resister or rheostat. According to an American writer, a/| ‘school requires a larger and better radio outfit than many private residences have, and the use of one of the latest and best receivers in a school creates a demand for better scts in the homes by a school also influences those conservative persons who wait until a new article or method is well established before investing in it. ea SO a eR eR! of the pupils. The adoption of radio |

The tremendous amplification of the superheterodyne receiver makes it possible to cover long distances with a loop aerial, and this usually is tuned with a variable condenser. Sometimes the Joop is tapped, so that more or fewer turns may be used. "Can't we have a lecture on weather forecasting by one of our meteorelogical experts from 2A, Wellington?" writes "Tiller? (Manawatu). "Many of us who have a special interest in weather effects would like to know how the meteorological experts arrive at their forecasts. I suggest that the lecture Le put on during the night session so that we all will be able to hear it.’’

‘he principal of a big Amer:can radio manufacturing corporation recently stated:- ‘Efficiency, simplicity, heauty--these are the characteristics of (1928 radio receivers, about the ultimate in meeting public requirements, Within the span of a few years, radio has been able to provide for the millions of listeners’ sets that work well and look well, A single control supplants the multiplicity of dials which were required on the early receivers. A child can tune in for programmes that are of the highest artistic standard. Radio thus enters a new year with the confidence of the public.

Announcement of the use of radio in prospecting for gold and other mincrals was made in the United States about a year ago. ‘This method is being scientifically worked out, with the hope that it will prove of rich practical value, That radio waves will penetrate 500 feet or more of rock strata was indicated in recent tests by the Burean of Mines in a mine at Caribou, Colorado. At a depth of 220 feet, Dr. Eve clearly heard a musical concert broadcast at Denver, fifty miles distant. Reception from Denver at 550 feet depth was "mushy," but disturbed conditions were believed — responsible. In general distortion arises either from improper operation and adjustment of the receiving set and its associated equipment, or from imperfect design of parts in the set itself. When improper operation or adjustment is the cause the trouble may lie almost anywhere in the radio receiver, Given a high-grade amplifier system and a loud speaker adequate to handle the output of the receiver, distortion may yet exist because of failure to. work within the power or voltage limitations of one or more parts of the recciver. The most frequent cause of curable distortion is overloading of the valves. Marconi, the Italian inventor, dliscovered the principle of wireless telegraphy in 1895 when but 21 years of age. Ihe Marconi Wireless Telegraph Company of America was the first company in America formed for the purpose of engaging in the transmission of messages by wireless, It was organised November 22, 1899, with a capitilisation of 10,000,000 dollars (£2,000,000) of which 25 per cent, was owned by the Marconi’s Wireless Tele. graph Company, Ltd,, a British corporation,