RADIO AND ITS RECEIVERS

Sun (Auckland), Volume II, Issue 505, 7 November 1928, Page 16

RADIO AND ITS RECEIVERS

Conducted for THE SUN by R. F. HAYCOCK. Automatic Tuning RADIO’S LATEST MARVEL Press Button and Listen THE latest novelty in radio, and one which attracted considerable favourable comment at the recent New York Show, is automatic tuning. This enables the listeners to merely push a button and to-hear the stations required.

Since the beginning of this socalled “mechanical age'* the demand of the people, the goal of the engineer, and the endeavours of manufacturers have been simplicity of operation. How true this is and how successful manufacturers have been is evidenced in almost every walk of life. In our offices we have automatic telephones, calculating machines, letter writers and time-recording devices. For world contact we have automatic telephony and telegraphy, automatic steamship and airship navigation. In the agricultural world practically all work of a laborious nature has been eliminated through the adaptation of automatic farming machinery. In the home we have automatic refrigerators, elevators, pianos, etc.; in fact, even our shoes may be automatically shined if we so desire. These things and thousands of other appliances are the result of the never-ending quest for simplicity of operation. MULTI-CONTROLS VANISH

When radio broadcast first caught the attention of the public, because of the mystery that was more or less associated with it. many believed that the number of controls and the intricacies of operating these various controls was, in a great measure, the

basis upon which the value of the radio receiver could be judged. In addition to this, because of the immediate overwhelming demand for radio sets, radio research engineers were not able to devote sufficient time in the development of radio circuits and equipment. As a consequence of these two factors, many radio sets were manufactured having a multiplicity of tuning controls that required the utmost in patience and skill to operate. In spite of this difficulty the number of radio set owners increased by leaps and bounds. Yet there were many prospective purchasers who, when confronted with the difficulties of operating such type radio receivers, unwillingly postponed the purchase of a radio set until such time as improvements were made upon the sets as to enable them to secure the most enjoyment commensurate with the least difficulty. Radio manufacturers, fully cognisant of the wishes of this latter class, made a right-about-face and their research laboratories worked feverishly night and day to perfect a radio set incorporating the smallest number of controls possible. Witness the early part of 1924, when, almost simultaneously, these manufacturers placed upon the market the three-dial radio receiver. The circuit employed had graduated

from the so-called regenerative to the tuned radio frequency stage, thus, through the elimination of shrieks and whistles, which were always a part, of the regenerative receiver, having improved reception to a marked degree. PUBLIC DEMAND IS INFLUENCE These improvements were not made in the laboratories and then offered to the public. Quite the contrary was true! The improvements were the result of the demand of the public for better radio equipment. So it can readily be seen that even in this early stage of the radio industry it was the earnest desire of the radio-minded to put radio in the same class of simplicity as was their automatic piano and talking machine. It was believed by many manufacturers, after the practicability of the electric receiver had been proved, that very few, if any, further improvements could be incorporated in the radio receiver. This belief was also held by the majority of broadcast listeners and it seemed that at last radio manufacturers would have a breathing spell, so to speak, to recover from the hectic demands made upon them by the radio ; world. It was generally believed, by consumer and manufacturer alike, that the millennium in radio had been almost reached and that further improvements would be manifest only in appearance and tone quality. The latest and most notable contribution is automatic tuning. It is doubtful if even that master of amazing tales, Jules Verne, could have conceived of such s.n instrument that would enable him to hear, by the press of a button, music coming from thousands of miles away. Yet just such a set is the automatic radio receiver. The appearance of the automatic differs in no way from the usual very fine console model. To the right of the tuning dial and enclosed in a small recess, which is concealed by a hinged panel on the front of the console, is the automatic control. On the front of this control box may be seen a series of buttons. Pressing any one of these buttons will bring in that sation to which the automatic control has already been adjusted. The broadcast listener arranges the various stations he wishes to hear on the automatic, thus making it possible for him to change at any time to ‘any statipn that he so desires. After once adjusting a button for any given station, it is only necessary to press that button whenever he wishes to hear that station. Of course, if he wishes to continue to use the old-fashioned method of tuning, lie can easily do so as the tuning dial is still there and works entirely free of the automatic mechanism. FUTURE OF THE AUTOMATIC Nothing remains stationary. We move either forward or backward. Complying with the unceasing demands made upon it, industry has moved slowly but consistently forward. Particularly is this true of radio. Let us analogise for a moment; the pioneer automobile owners of earlier days were in a great measure responsible for the improvements that we now generally accept without giving a thought to their origination. Consider for a moment the simple act of starting the engine. It was not so long ago that this operation involved considerable skill and no less manual effort. To-day we press a button and the motor goes into action. Automatic! The result of progress. The result of a definite need on the part of the motoring public. In like manner has the work of the household been lessened. Vacuum cleaners, electric washers and electric cookers fulfil an actual need of the home. Daily we hear the evidence of the popularity of the automatic player piano and phonograph. In relaxation, as in our work-a-day labours, automatic devices have made it possible for us to more fully fill out our life span—and to do this with a minimum amount of waste of time and effort.

BYRD’S EXPEDITION RADIO’S BIG PART Every human effort has been expended to make Commander Richard E. Byrd’s forthcoming expedition to the South Pole a success; and prominent among the instruments of science which he will use is radio. Whether the expedition meets with the reward that its intrepid commander’s foresight and courage merit, or with an undeserved failure, remains for the future to tell; but radio has anticipated every conceivable contingency that might arise, with the idea in viev of keeping up constant communication between various elements of the expedition and the base and between the base and the rest of the world. Every party that leaves the base, whether by dog sled or by airplane, will be equipped with short-wave transmitters and receiving sets; and every man in each party will be able to send and to receive code so that in case the regular operator is disabled the available substitutes to establish communication with the base will be limited only by the number of other men in the party. For this purpose, all members of the expedition will receive instructions for one hour each day on the voyage south in sending and receiving radio messages. Radio receivers and transmitters will be installed at each sub-base, so that if it becomes necessary for Commander Byrd or any of his companions to walk back from the Pole, in case they are forced down, they will not be confronted with the alternative of having to burden themselves with portable sets from their planes or being without means of communication to make their plight known to their companions. In all, there will be a total of 20 transmitters and 26 receivers carried by the expedition. The complete radio equipment, including the accessories and parts necessary to keep all installations in operating order for two years or more, is valued at close to £15,000. Of this amount approximately 50 per cent, represents contributions made by radio, electrical and accessory firms. The remainder was purchased at very liberal discounts. Short Waves Used

The principal reliance of Commander Byrd and his companions for communication will be placed on short waves. Nine channels below 100 metres have been assigned to him. They are 91.3, 68.1, 53.1, 45.6, 34.06, 26.5, 22.8, 17.95 and 13.72 metres: but most of the work is expected to be handled over the 45.6, 34.0 b and 22.08 channels. In addition to these channels, three intermediate wave lengths will be employed. These are 600 metres for callings and distress signals, 730 metres for communication, and 800 metres for the radio compass.

There will be eight stations in all carried by the expedition. Commander Byrd paid a touching tribute to his late companion, Floyd Bennett, in designating his plane and the station it carries as the Floyd Bennett, with the call letters WFB; so in fitting manner the memory of the heroic navy flyer who gave up his life carrying aid to the stranded crew of the Bremen at Greenley Island will accompany his commander over the South Role as his indomitable courage and spirit flew side by side with him over the opposite axis of the ea,rth. Xhe call letters of the stations are WFBT, Supply Ship; WFA, Base; WFB, Plane Floyd Bennett; WFC, Fairchild plane; WFD, Advance Base; WFE. WFF, Fokker plane, and KFK, Advance Base.

Alalcolm P. Hanson of the Naval Research Laboratory, “Bellevue,” at Anacostia, D.C., will be the radio engineer in charge of the expedition’s equipment. He is 33 years old and served in the navy as radio officer during the war. He was educp.ted at. the

University of Wisconsin, where from 1920 to 1924 he had charge of the construction and operation of the university’s broadcasting station. He was

detailed by Secretary of the Navy Wilbur to accompany the Byrd expedition for the purpose of establishing adequate radio communication between the planes and the base. Another member of the expedition’s radio crew is Lloyd V. Berkner. who was detailed to it by the Department of Commerce. Mr. Berkner is a qualified Naval Reserve pilot and holds a commercial transport pilot’s licence. Howard F. Mason, who worked with the Wilkins-Detroit Arctic expedition in 1926 and 1927, and Lloyd K. Grenile, who was chief radio operator with Commander Byrd’s expedition on his North Pole flight, will also be associated with Mr. Hanson. New Type Antenna The three airplanes employed by the expedition will employ a type of antenna not heretofore used in work of this nature. It is called a doublet, and consists of two sections, one being swung from the tip of each wing to the ship’s tail. Each section will have a separate feed line. This permits the plane to use its radio when it is on the ground as well as when it is in the air. The radio equipment has been divided into three parts, supply ship, expedition base and aircraft, and will handle only code. The supply ship Samson will carry a short-wave transmitter and a transmitter working on the intermediate band between 600 and 800 metres. Two short-wave receivers, one for listening and the other for radio research work to aid in making tests on fading, will also be carried on the Samson. Malcolm P. Hanson, radio chief, will have a power output of 1,500 watts, employing two 750-watt tubes, on his set. The auxiliary transmitter power will be supplied by a five-kilowatt gasoline engine. At the base, one mile or more inland, two two-kilowatt generators will work the station. The operating room will be soundproof, so as to ensure the best reception. The radio equipment at the base is similar to that aboard the Samson with the exception that the short-wave transmitter will have a 500-watt output. The base antenna will be strung from three steel towers, each 65ft in height, and supported by four supports to secure them against the wind and prevent them from sinking in the ice. The plane will carry 50-watt combination low and intermediate wavelength transmitters. Power for these will be supplied by generators driven from the central engines of the ships. Places are also being provided for wind-driven generators for emergency use. The flyers will employ 34.00, 68.1, 91.3, and 650 metres for communication purposes with ship, base and sled parties. The airplanes will also carry 401 b portable transmitters and receivers in crash-proof cases. These are for use in case of accident. Sled parties will carry similar equipment worked by hand-driven generators and batteries. Thirtyrfoot sectional bamboo antenna masts will be used to support the aerials. _ Firms Donating Equipment Among the firms donating equipment were the Burgess Battery Company, whose gifts of batteries and sets are valued at £ 300. The sets comprise five portable transmitters and receivers for use by sled parties and the expedition’s geologist. Professor Lawrence Gould of the University of Michigan. The Electric Storage Battery Company contributed all storage batteries to be used on the two-year journey. These were valued at £320. The same concern also supplied ship emergency batteries, repair kits and parts. The Kolster Radio Company furnished two directionfinding compasses, one for the ship and one for the main base, so an accurate check can be kept on the planes; two broadcast receivers, eight loud-speakers and 18 navy type headphones for aviators and operators. These phones were treated with a special preparation of beeswax to enable them to stand the severe Antarctic temperatures.

CAPTAIN COURTNEY’S RESCUE DUE TO MARCONI RADIO No details are yet available as to the use made by Captain Courtney of his wireless apparatus during bis flight from the Azores, but the following telegram has been received by the Marconi Company in London: “Rescue entirely due to Marconi wireless.—Courtney.” It is evident from the fact that Captain Courtney’s airplane came down off the main shipping route that unless he had been carrying wireless he would, like so many previous Atlantic flyers, have disappeared into the unknown. This wae fully realised by Captain Courtney, who has always emphasised the importance of wireless being carried by anyone attempting the transatlantic flight. In fact he regarded any attempt at flying the Atlantic without wireless as being suicidal, and it is a striking fact that his own life and the lives of his companions should have been saved by this conviction. The Marconi wireless transmitting and receiving set which he carried was similar to the apparatus with which all the Imperial Airways passenger carrying machines are equipped. It has a normal range of about 200 miles when in flight and includes arrangements for emergency transmission in the event of a forced descent. After landing on the water Captain Courtney and his companions would have raised an emergency aerial on the wings of the flying boat and have transmitted their messages by means of the emergency battery. The range obtainable by this means would be between 70 and 100 miles, and the power available would have been sufficient to enable them to send out messages at intervals was done hours providing no damage was done to the apparatus. Other striking instances of the life saving and navigational value of wireless in long flights have been provided by Major Franco’s flight from Spain to South America, and the recent American flight across the Pacific. TRICKLE CHARGING “Do you think it is injurious to an ‘A’ storage battery to allow a trickle charger to constantly charge it?” writes a correspondent. “I have had storage battery for five years and have charged it the same each week, while a friend who uses a trickle charger has had to have three batteries in one year. Pie claims that a trickle charger kills a storage battery, due to the steady gassing. Is he right?” Gassing is natural with all lead-acid storage cells while being charged. If the gassing is very violent it indicates that the cells are being charged too rapidly, but a trickle charge, which cannot be construed to be more than onethird to one-half ampere for the average size of radio battery, never produces violent gassing and cannot be the cause of injury to the cells. A storage battery is kept in good condition by constant charging and discharging at approximately the service rate for which it is designed. Manufacturers of radio “A” storage batteries say a trickle charge sufficient to supply in a certain time 25 per cent, more electricity than the cells are supplying the set is about right to keep the cells in first-class condition. A slight overcharge is often necessary to restore the cell’s efficiency and reduce what is termed “sluggishness.” If the charger is not sufficient to keep the cells near full charge and frequently give a slight overcharge sulphation may then cause

MAILS BY AIR BROADCAST COY. COURTESIES When Squadron-Leader Kingsford Smith and Flight-Lieutenant Ulm decided to fly to New Zealand in the Southern Cross, the New South Wales Broadcasting Company, Limited, sent greetings to the Radio . Broadcasting Company of New Zealand through the courtesy of the flyers. The following interesting .letter has now been received by the New South Wales Company, which also some to hand by courtesy of the Southern Cross: 4 Dear Sirs,— Per kind favour of SquadronLeader Kingsford Smith and FlightLieutenant Ulm, on return trip from New Zealand to Australia. We take the opportunity of the return flight of the Southern Cross to Sydney, and of the courtesy of Squadron-Leader Kingsford Smith and Flight-Lieutenant Ulm, to acknowledge with the greatest pleasure the greetings conveyed to us in your letter of the Bth inst., which was conveyed across the Tasman in the first airplane to reach New Zealand’s shores from overseas. The occasion has been an historic one for our two countries, and to us who are engaged in broadcasting it has had a special appeal on account of the part that radio has played in the enterprise. We are also interested in this other means of annihilating distance and time. Your stations and ours, which speak nightly to people across the Tasman, have been the means of drawing our two countries closer and closer to-

gether, and this rapprochement &*•' been cemented by the rapid flight of tali eavier-than-air machine from Y°“ r land to ours. The ethereal and material connection between the t v countries cannot but be for The Southern Cross will leave Chrt church this afternoon for where she will leave New Zea»” soil on her flight back to AustraHer departure is timed for SunG-> morning, and we trust that the a* r men will be safe at Richmond au drome by the evening, when we • take the liberty of rebroadcasti.--your description of the landing. Hearty greetings by the » airplane to leave New Zealand Australia. (Signed) A. R. HARRISGeneral Manage Squadron-Leader Kingsford also took a letter from the comP* 1 --.. for Mr. Ray Allsop, chief engine* the 2BL service, who controlled remarkably successful broadcast ox arrival of the great plane whicn made history. VOLTAGE REDUCTION DEVICE A new lighting-line voltage reductdevice for use with all-electric se prevent their valves from prematurely has been introduceddevice is provided with venti openings to facilitate the escaV* .. heat from the resistor. The res i® , plugs directly into a base-tk> other lighting socket, and tne c j f cord to the set plugs into a rec P on the other end of the unit. * resigned for all AC voltages ti above 110 volts, and for set - 5 ,<> draw between 0.4 and 0.6 amp line current.