THE WIRELESS WORLD.

Otago Daily Times, Issue 20690, 12 April 1929, Page 5

THE WIRELESS WORLD.

NEWS AND NOTES. By Magna Vox. Items of local Interest are Invited by “Magna Vox" for publication in this column. It Is necessary that such matter should reach this office by Tuesday of each week for insertion on the following Friday. ANSWERS TO CORRESPONDENTS. D. M‘G., Wakari.—Unfortunately your query was mislaid, and I am therefore unable to publish tho reply in this week’s column. Will answer next week. R. M., Balelutha. —(1) Approximately .00035 mfd. (2) Yes, with adjustment they would be quito suitable for use with the coils you mention. “Puzzled,” Port Chalmers.—K.M.T.R. is a Los Angeles station, which transmits nightly on 526 metres. KFI is also a Los Angeles station with a wave length of 468.5 metres. “D. X,” Maori Hill. —Tho dead spot which occurs in tuning your short wave receiver is probably caused by too long an aerial. Increase the aerial coil coupling and reduce the length of the aerial or. place a fixed condenser in tho aerial lead. G. R. M‘F., Tainui. —A quick test to dectermine whether the electrodes on your lightning arrester are shortcircuited or not is to hook it up in series with a pair of headphones and a battery, and whilst listening with the phones, complete the circuit by touching one of the cord tips to the lightning arrester. If a click is heard your arrester is defective, and" should cither ho replaced or repaired. “A and B,” Dunedin. — Place the battery on a slow charge and slightly overcharge it. ‘Discharge again by leaving it connected to a six-volt valve or other current consumer that takes a fairly heavy current. Discharge as quickly as possible then charge again slowly,land after emptying the acid replace it. If you find the battery still does not hold the charge, it will probably bo necessary to take it to pieces and examine the plates which may have become buckled, or perhaps they may have become shorted by paste which has fallen to tho bottom of the cell. 2YB, NEW PLYMOUTH. The transmitting plant for 2YB, New Plymouth has been despatched from Wellington. It was first intended that a temporary power plant should be installed in order to expedite operation, but as the permanent power equipment is due in Wellington by the s.s. Keelung in the immediate future, it was deemed best by the interests concerned to await its arrival and start the operation of this relay plant with everything in good working order. Certain details regarding preliminary equipment, etc., still require finality in New Plymouth, but it is anticipated that the official opening will take place very soon, and that 2YB will be on the air probably before the end of this week. A WONDERFUL BROADCAST. What was referred to as the “greatest event in radio broadcasting ” was, carried out recently by the sort-wave station of KDKA, Pittsburgh, U.S.A. The announcer stated that, as signals were being received so well from WFBT. the City of New York, at Little America, Bay of Whales, Antaretia, they had asked Commander Byrd to send a message which would be picked up by them and re-broad-cast. At 12.22 a.m. eastern standard time (5.22 p.m. N.Z. time) this message was commenced and was heard here very well after having travelled 11,000 miles to ■ Pittsburgh and the same distance back again. The operator on. the City of New York heard his own signals after they ..had covered a distance of about 22,000 miles. The message was in reference to tho weekly broadcasts for the expedition from KDKA. stating how well they were received and enjoyed by all the party. At present they were having 24 hours, per day daylight, but in about lj w o months they would have continual darkness, when the weekly- broadcasts would be even more appreciated. The message concluded with: “Best wishes-to all at home.”—Signed, Commander Richard E. Byrd. Both before and after this special message, personal messages were sent to residents of the Arctic and to members of the Antarctic expedition. All was heard at good volume on the loud speaker, WIRELESS IN HOSPITALS. . -f’he movement for installing wireless m the hospitals throughout the Dominion is steadily expanding, and news is regularly coming to hand of one provincial centre after another undertaking such installations. Timaru is now in the process of equipping her hospital with radio, and is in' the midst of a campaign to secure the last £3O to complete the scheme.i The set at present in operation is • a five-valve, machine, which is doing good work. Eventually an' eightyajvo sot will be utilised to feed the large number of Sjcadphoncs to be used. The aerial is 125 feet in length, supported by strong steel masts 60ft in height. It was originally desired to secure £3OO, but so far the public have contributed nearly £l4O, and -at present a campaign is on foot for a further sum. from special articles which have been appearing in the Timaru Herald, striking testimony as to the value of radio to- hospital patients is culled. Very pathetic indeed and very effective are some of the stories_ quoted by tlhc press correspondent who visited the hospital. “We are only " iting till 3 o’clock for the wireless to be turned on,’ said some patients to the reporter. One patient said, “ would like to express my appreciation of ttie wireless that is being installed. It is an excellent innovation, an l will help pass many a weary hour.” “ I am a ffttle girl,” is, another extract, “and I have been on my back in hospital for nearly four years. I have no headphones, but sometimes I share a pair when my bed is moved alongside ray neighbour’s. I love the wireless, and I wish somebody would be king enough to give me a pair of headphones !

4YA TO THE FORE. All local listeners-in are ready to congratulate 4YA on the initiative it displayed in broadcasting reports and warmings during the recent flood, and the staff, who worked so hard in keeping the transmission on the air until long after midnight, have earned the thanks not only o listeners, but the public generally in performing what was a very real service to the community. By 6 o’clock on the evening of March 1!) 4YA was able to advise motorists of the dangerous conditions of portions of the roads about the city. Throughout the news session reports regarding affected areas and state-of roads were made from time to time as they came to hand and by 8 p.m. an organised system of detailed reports from all parts of the city and as far as Waitati, 17 miles north, and Waipori, 42 miles south, were on the -air. Arrangements wore made with the Fire Brigade department, the Otago Motor Chib, the Railways Department. Tramway Department. Police Department, and Lity Ligbtiue Department to communicate reports of conditions to the stations, and with the 'assistance of listeners at various points of the affected areas in the city. 4YA soon became the centre of inquiry, and from the announcements made listeners were in a position to judge how the affected areas were faring. At 0 o’clock the announcement” was made that, if necessary, the station would remain on the air after the ordinary hours of transmission, and reports were madefrcquently until 10 o’clock indicating that the flood waters showed no signs of receding. It therefore became evident that though the station’s normal hours of transmission had concluded it would be in the interests of listeners for the station to remain on the air in adherence to the company’s policy of service to the listener. Reports in regard to the train services were received, and broadcast up till the time of closing down. By midnight it became evident that the waters in the flooded areas showed signs of receding, and as the weather generally had a clearing tendency the station intimated that transmission would be discontinued as soon ns final reports in connection with the train services were received. These were to hand by 12.30, and the station closed down at 12.40, with the definite assurance that there was no need for further alarm. Continuous reports ns to the position had, therefore, been made over a period of

some nine hours, covering the initial report regarding flooded areas at Kensington until the weather showed definite signs of improvement. WIRELESS FOR AEROPLAXEt,. Radio apparatus for airplanes is rapidly becoming highly specialised, and is developing at, a rapid rate. At the present time three distinct pieces of apparatus are evolving—the receiver, the transmitter for both short and long wave, and visual indicator. Of the receivers both short and long-wave instrument? arc being perfectly rapidly. Among the most potent factors to be strived against is noise* from the engines, and that is due to the passage of the plane through the air, as well as the electrical interference due to the magnetos. To meet these mechanical disturbances special helmets are being provided, which are sound proof, and which embody ear phones. Of the transmitters several types are appearing, many under the familiar name of Marconi. These are designed to meet the special requirements of each type of machine, long-range tele-graph-telephone instruments for the heavier class of plane, and light telegraph instruments for the lighter class of plane. The weight lof these transmitters varies from about 821 b to 1801 b, the range being from 15 miles to very many hundreds of miles, as evidenced in the transtasman and other great flights. Direction finders are becoming increasingly popular with airmen. An air pageant staged some six months ago in England provided an excellent opportunity for demonstrating the advances made by aviation and radio. The wireless or electrical side of the pageant may roughly be divided into four classes —the land-line system, for communication between all points of the aerodrome. the intcrplane and ground control system, the Marconiphono public address system, and the 8.8. C. arrangement for providing a running commentary to listeners. Over 50 miles of land-line were used in conjunction with 41 loud speakers, which latter required.over one horse-power of energy for their operation, or, roughly, 10,000 times that delivered to the average home instrument.