THE RADIO WORLD

Southland Times, Issue 19357, 24 September 1924, Page 15

THE RADIO WORLD

LOCAL NEWS AND NOTES. (By “Reflex.”) Great, excitement reigned amongst the amateurs on Sunday night. 4 A.A. (Mr F. Bell, Waihemo) was heard calling United States 6 B.CJP. and that station heard him and replied. Communication was maintained for some time and then 4 A.A. called 6 C.G.W., and raised him too. By this feat, 6 B.C.P. wins “Q.S.T.’s” boomerang, as the first U.S. station to get into two-way communication with New Zealand or Australia. Later in the evening 6 C.G.W. was heard calling 4 A.G. (Mr R. Slade), so it would appear as if the latter’s ether buster has got over at last. This was a remarkable performance, considering the low power used by 4 A.A. The power input used was 120 watts, the radiation 1.1 amps, and the length 140 metres. The U.S. stations heard use about 2000 watts. At Friday night’s meeting of the Invercargill Radio Club much was heard of howling valves, and some of the leading members have decided to enquire into matters by means of a loop set mounted on a car. They will hunt for illegal circuits, and also give a few hints to those who are causing the interference. The wireless operator from the steamer Tredinnick visited 4 A.A. in company with several Dunedin hams during the week. At home in the States he uses a 1 kilowatt spark set, and a 100 watt C.W. set and has heard 4 A_A., 4 A.K., and 4 A.G. there. On Sunday night conditions were fairly good for the concert broadcasted by 4AP. fhe studio has now been draped with material, which reduced the echo and rendered matters much more satisfactory. A steady improvement has been taking place in the quality of the programmes sent out and Sunday’s was probably the most popular yet given. Items were contributed by Mr and Mrs L. Chaddick, the former’s novel whistling solos being very popular, and Mr E. Miller, while several catchy choruses were introduced. Reports state that reception was fairly good, and larger programmes are contemplated as the result of the success of those already given. One of the largest wireless frame serials in Europe has just been put up on the roof of the tower of the handsome Bush Building, in which the offices of The New York Herald Tribune are located. It has been erected by the United States Shipping Board to conduct its business between London and the States. Because at one time or another radio fans have received stations 1500 miles away they think that this is the receiving range of their set, and if asked what the range is they will give this mileage. This is the wrong way to estimate the range of a set. The proper method is to see how far the set can receive signals in the day time, between 11 o’clock in the morning and 4 o’clock in the afternoon. Stations that can be picked up regularly between these hours are the ones upon which the reccxving range should be based. DANCING TO KGO. REPORT FROM WAIMATE. In a recent issue of the New York Her.i •. tribune Radio magazine appears a letter from Mr T. D. Blackwood, a Waimate u. .tcur, who writes: “Every Sunday evening the family dahees on the front lawn to KGO music loprufluced by our loud speaker. We always look forward to hearing KGO, and there is a disappointed household when the atmospherics are bad.” Owing to nineteen ho uro’ difference in time between New Zealand and the United States, music received by the Blackwood family Sunday evening is played at KGO (California) Saturday night. From the Far North, within fifty miles of the Arctic Circle, another letter has been received. “We have danced to music from KGO on several occasions,” writes G. H. Hillman, of Candle, Alaska. “It is certainly great to have dance music carried into the Arctic.” Mr Hillman is the operator of the Candle radio station. “The wireless station installed here his summer,” he continues, “is a new thing to people in this section. Most of them have not been outside for twenty-five years and it is hard for them to realise that KGO voices and music come from a distance of over 4000 On the basis of figures for the year 1923 it is probable that the American people will spend approximately 350,000,000 dollars for radio equipment during the present year. A conservative estimate of the business in vacuum tubes alone is about 50,000,000 dollars. At least five times as much, or 250,000,000 dollars, will be sent for radio sets and parts. The sales of batteries, both dry cell and storage batteries, will very likely amount to over 45,000,000 dollars. Miscellaneous equipment such as battery chargers, loud speakers and specialties may easily account for 50,000,000 dollars more.

If signals are being received the quality of the reception is at once a guide to whether your receiver is 0.K., or whether it is oscillating quietly. If the set is oscillating, music or other telephony will be distinctly mushy, and possibly mixed with undesirable roars and squeak; morse will become much louder, but stations will lose their distinctive notes and will become hoarse, atmospherics will also become increased in strength, and, lastly, the carrier wave will be picked up on tuning away from the “dead” point. To find out from your own receiver whether it is oscillating quietly, touch, with a damp finger, the grid terminal furthest from the valve or the aerial terminal; if everything is 0.K., a “pop” will be heard on the application of the finger to the terminal, but none when it is removed; if the set is oscillating, however, two “pops” will be heard—one on the application of the finger and another when the finger is removed. Turning the reaction coil or variometer from zero to maximum position should also cause a slight “pop” to be heard; immediately the “pop” is heard the set is oscillating. A similar test can be made by turning the filament resistance from zero to working point. The Wireless Telegraph Company of South Africa, Ltd., has been recently organised to provide international telegraphic service for the Dominion. The principal high-power station is to be located at Klipheavel Station, Cape Province. The site comprises about 1000 morgen (2110 acres) of farm land, and is so located as to be about ten miles distant from any mountains. It is estimated (hat the station will be in operation in about 18 months. The power of the new station will be 750 kilowatts, and it is probable that it will operate on a wave length af about 16,000 metres. The aerials will be supported by 16 towers 800 feet in height, arranged in the form of a circle, having a diameter of 14 miles. Beneath this circle an earth screen was determined as the result of experiments carried on at the Marconi station at Carnarvon, Wales. This South African installation, together with the stations planned for Canada, Australia and India, and the existing stations in England and Egypt will form an Empire wireless system, each one being designed to communicate directly with the Mother Country or with any of the other dominions. G3AND OPERA. BROADCASTED FROM SYDNEY. Successful broadcasting of grand opera has recently been carried out from Sydney by Farmers’ Broadcasting Service, 2FC, in conjunction with the J. C. Williamson Melba Grand Opera Company. The operas were clearly received m all parts of Australia. The technical difficulties of successful broadcasting from Her Majesty’s Theatre were overcome by careful organisation and strict attention to detail. A microphone was placed on the front of the stage, quite close to the footlights, and yet out of view of the audience, connection being made to a special power amplifier in the basement of the theatre. The output circuit of the am-

plifier was connected by land line to the main control room of the service on the roof garden of Farmer’s premises in Pitt street, where further amplification was obtained, the signals being then transferred to the transmitting plant at Willoughby. Every precaution was taken to ensure perfect transmission, and at all points of the service careful watch was kept on the working of the various instruments, radio engineers and musicians co-operating closely to ensure that the correct tone of the various numbers was broadcasted. In the basement of the theatre a member of the musical staff, attached to the service, followed the score of the opera and aided the operator and engineer in the control of the amplifying panel. At the main control room similar action was taken, and an efficient receiver was used so that those controlling the operations were able to listen to every word and every note of the entertainment. Australian reports have indicated the unqualified success of the attempt. The transmissions from 2FC are providing the best broadcasting entertainment in Australasia. The company is now broadcasting on Sunday evenings from 9 to 11 p.m., New Zealand time. TRANSMISSIONS FROM KGO. FOUR TIMES A WEEK. Mr C. W. Rhodehamel, publicity director of KGO, Oakland, California, makes the following announcement: —“That radio listeners south of the Equator, in the islands of the South Seas, New Zealand and Australia, may enjoy a better broadcast service from KGO between 10 pan. and 1 a.m. (Pacific time). It is announced that beginning immediately, Henry Halstead and his orchestra, playing in the Hotel St. Francis, will be heard in New Zealand on Tuesday, Wednesday, Friday and Sunday nights. Soloists from Halstead’s orchestra will play between the regular dance numbers, keeping up a continuous broadcast. It is winter time now south of the Equator, and the best season for radio reception. A difference of 194 hours in time between New Zealand and the United States makes it difficult for listeners south of the Equator to ‘log the Yanks’ unless broadcast after ten o’clock, Pacific time. However, some reports have been received on KGO regular programmes broadcast between 8 and 10 p.m. Henry Halstead states that he will appear occasionally himself before the microphone, and that various soloists of his orchestra are preparing special numbers to ensure a continuous programme for the big audience of the South Seas.”

In future, then, it will be possible in New Zealand to hear KGO four times a week up till 8.3 Q p.m., New Zealand time. Such a decision by the owners of KGO indicates that they must have received many satisfactory reports on reception of their broadcast by New Zealanders. AF. TRANSFORMER FAULT. WHAT TO WATCH FOR. It is commonly assumed that transformers always break down because of overload. Oftentimes, however, the cause is far different. The windings of an audio frequency transformer are called upon to carry comparatively heavy low frequency impulses of varying audio frequencies. The louder the signals the stronger are these audio frequency impulses. If the windings of a transformer were microscopically examined whilst audio frequencies were flowing through them, it would be seen that they were vibrating in sympathy with the frequencies they were passing. If the windings have not been designed bearing in mind the conditions of service, although the effect of the vibrations might not be immediately obvious, the ultimate effect would be to alter the molecular formation of the copper in the windings and render the wire crystalline. Once the windings have reached this condition, it is only a question of time before the user will one day be surprised to find his transformer no longer functioning. Unfortunately, even expensive transformers -are .not immune from this fault. REPAIRING A BREAKDOWN. The owner of a transformer that has broken down will do well to find out first what a rewind will cost, as in a great number of cases it is cheaper to buy a new transformer than to have the old one repaired. Another fault that has been cropping up of late is the breaking of the fine wires of the windings where they are soldered to the four terminals. This is caused, to my mind, through the use of “flux” that has some acid in it that sets up corrosion in the fine copper wire, and in a short time makes the wire too thin to stand any vibration. It is just as well, when a transformer refuses to amplify and a test shows an open circuit, to have a close look at any of the soldered joints before discarding the transformer. INCORRECT WINDINGS. Still another common fault is the incorrect connecting up of the transformer windings to the terminals, by 'the makers of the instrument. Quite a number of cases have come to my notice where the secondary winding has been connected to the primary terminals and vice versa, or perhaps, one secondary lead connected to primary terminal and the other secondry lead O.K. If you ever come across a transformer that reduces the signal strength instead of amplifying it, give the connections the « “once over.” Never believe the ticket that is generally attached to the transformer by the maker, stating that it has been tested by “so and so” and found O.K. I have learnt my lesson and am handing the tip on to my readers.