REVELATIONS OF RADIO.

Shannon News, 2 November 1928, Page 3

REVELATIONS OF RADIO.

SCIENCE THAT OPENS UP A NEW

WORLD,

A CHAIN OF DISCOVERIES

. Members of the Levin Chamber of Commerce Lunch Club listened to an address on a fascinating topic on Friday, when the-'.Rev. H. • Spencer, of Otaiti; spoke on "The How. and Why of Radio." Mr Spencer las an intini--ate knowledge of the workings of Wireless instruments, and his remarks were .'all the; more interesting beeause he took into consideration the farTreaching future possibilities indicated as the "result of'; research ,iiu radio, science. The gathering ' was attended by about 'twenty, ... and was presided over by Mr F- G- Parker, who suitably, introduced'the speaker. '• EARLY EXPERIMENTS.

Dealing firstly with the genesis of wireless communication, Mi- Spencer said it was the common conception that Signor. Marconi was at the foundation and head of the discovery, but this -was not altogether correct- It 'Was necessary togo back to the days of Hertz and Franklin and various ether scientists, because their studies and experimerrts wore behind this wonderful science. 'The practical side of radio .began with,'Sir Oliver Lodge, who had laid the. foundations of modern wireless on which other men had built It was one of Sir Oliver's addresses which, in printed form, had.so appealed to Marconi when a boy/that lie 'decided to' make the subject his life study, In 1896 Marconi demonstrated his apparatus for wireless.' signalling, and in the following .year Lodge brought out a method for tuning.- Had it not been for .what might be called the side-issue of Lodge's diseovery; .it would have been impossible, j'to'. have .jriore".than one broadcasting ! station in a country. Twenty-eight years ago on Christinas Eve, a small coastal, vessel put out from the Good-, wiii iighthouse, with - the first set for sending and receiving by wireless, and" messages were received from the then incredible' distance of 12 miles. .Not loii'gt afterwards, the first rescue at sea .through the medium, of radio was effected, the E. F. Matthew . bringing her machine' into play when she was foundering. That rescue set the nautical authorities' thinking hard, and they saw in* this new-fangled (notion the future salvation of many lives. IMPROVED METHODS. :

"Spark* transmission," said the lecturer, "is dying out, and, spine of us think that the sooner it docs so. the' better it will be for radio in general." He explained that spark transmission used a 'very broad, wave, and the reception by this means was spoilt by transmissions from other sources,, including certain ships at sea. Ten years ago he l'istened-in to spark transmission and thought what a wonderful thing if was, the reception being over four or five hundred milqs. Since theii he had. made anything but nice;•-.>re-" marks 'about; spark ; transmission.'.' it was dying" out, and , the authorities were., equipping all ships with valve transmission, which made it possible to tune a wave to a point. The fault's o'f spark transmission were similar to the interference from the electric current of the post office and the power authorities, which was broad in wavelength.- .' ■ - ■!.■.' NEW;; ALADDIN'S LAMP, The- wireless valve, the 'speaker timied, was the ',.' modern Aladdin's lamp, and one of': the, greatest wonders of the world's history. m ,The attention of Professor Fleming hatl been attracted to a dark deposit on inside of elec-tric-globes, and he found that it was produced "by /millions of ; electrons discharged 1 from the filament. .--This discovery led to the. birth of the radio valve. In the valve by Prof. Fleming there Were two'electrodes.' Dr. Forrest wanted a more, selective valve, and he put in a grid. The first intelligent speech through radio was transmitted a?,ross Forrest's laboratory in 1907. ".:. •-"'■; ,

Much curiosity was felt by the layman .as to how the wireless'•: waves carried the sound to the listener. The transmitting was done by what was called an oscillating • machine, which made the set completely alive. The microphone looked a very harmless and innocent instrument, but it would cause a whisper to be sent unknown distances. It* superimposed the human voice on the current, subsequently putting it out on the aerial by tremendous voltage. The current had to go somewhere, and it went out everywhere. The waves travelled at the rate of 186,000 miles a second, the same a? light, and the speed was always the same Avhether the frequency and wavelength were high or low, long or short. Sound travelled at floii feet per second. A few months' ago, he... tuned-m to oSW. London, a short-wave station, and listened t 0 some items. '■ Assuming, that the theatre was 100 ft. in length, he at his set in Otaki heard what was being said or sung sooner than the.doorkeeper of the theatre, for ...whereas it took the sound unaided .1-12th of a second to reach the man at the door, it was received on this side of the world bv wireless in' I-lfith of a second.

AFFINITY WITH SUNLIGHT

There was a wonderful similarity between the' wireless wave and sunlight, and this opened up a great held of thought. Sunlight was on such a short, Wave-length that scientists could not duplicate it, but Iprobably the time would come when they would be able to produee high-frequency .elci'H-ic current on'the same wave-length, and then they would produce light itself. ; The beam service represented waves confined and reflected, .an analogy for which, was to be found in the b?adlights of a motor-car. When th? waves could be reflected more effectively and confined entirely, something very strange might be expected 1o happan. People with wireless receivers found that .their sets were more efficient at (night than in th day-time. -Many opinions were held as to why this

should be*so. It was acknowledged by all scientists that, sunlight affected the radio frequency. His own view was that the sunlight was electrical energy, that attended with the radio wave and brought down its frequency. It was common knowledge that the sunlight had medicinal and curative pro: perties; it made people feel youngov. They were told that in the. world there were always raging 40,000 thunderstorms. Electrically speaking, the clouds formed one plate of a'condense r and the earth the. other. , With two plates —a positive "and a negative —i;: was possible, by using sufficient energy, 1 .to make a spark jump from one to another. A thunder-cloud was built up by the action of the sun, and was really aii■accumulator, of tremendously high' voltage. When the air could no longer keep ba:-k the, charge, it broke from the negative plate of the sky to the positive plate of the earth. : Th« sneaker gave an instance of the eurrerl in a' thunderstorm charging an aerial, and stated that sometimes, if a-.radio set was not earthed, a spark would jump across the, condenser plates'. Insurance companies were wise in their demand rthat every radio set should be provided with arresters. . Mr Spencer mentioned that the human body was an aerial, and that he had made use of a chain,of boys at Otaki to demonstrate this fact. v |"he wave was conducted the more easily if the hands were moist. It could not be felt, and the experiment was harmless. •The speaker explained 'that the terms "fequency" and "wave length" were interchangeable, the former de signation being used by the Americans. The shorter the wave-length, the higher /the frequency. Station 2YA (Wellington) worked' on a wave length of 420 metres, and this would be described in America ;as 750,000 frequency-'

SAUSAGES COOKED ON AERIAL. ■ One :of,'the strangest happenings of modern times-was the invention of a new valve, which would operate on' a wave-length 'of six metres. The Gen-' oral Electric ■Company of America had made it ;fqr 50 million frequencies per second. Strange things happened with, , it.' The- men who were oporating the new valve felt, themselves being cooked from within. Tliey hung some sausages on the aerial and they were cooked in a few seconds.. An ordinary electric lamp placed on the floor a few yards from the valve glowed with a.' dull red light The metres ran wild. ' What was going l to result from the discovery was as'yet unknown; but thj) engineers realised, that when they produced a frequency like that, they had, to treat the valve with very great respect indeed. ' ' ' - Various parts of a wireless receiving set were shown by Mr Spencer, and their functions explained. He stated that radio high frequency knew no insulation, and presumably if Went on for ever. A report was recently published in the Press concerning the dis-_ eovery that a crane, used on a build--ing 120 yards from Station 2LO, in London, had become electrified. The workmen had received a nuniber of shocks, and it %yas found that, when 2LO was broadcasting, the crane was carrying, a current of, 320 volts, and that there was sufficient energy prtsent to light a, neon tube. Tie did not think that the whole cause of the trouble came from the, wireless station. Tests would probably prove that the high building, with;, the lei.g chain hanging from the crane, was gathering •electricity from the atmosplu re, "and that a t«mal] amoirnt ■received from the wireless staton, added to this, caused the shocks to th*3- workmen.

Mr Spencer expressed his regret at not being tible to go further into the .Subject'..'of radio science on this "occasion,- owing' to insufficient time being available.

Mr ;C, S. Keedwell, "President of the Chamber of Commerce, t-iuh'rl the thanks of .the gathering \v Mr Spencer 'for 'lus interesting .'iud informative address —a sentiment which w:ts demonstrated ,by the hearty applausa if.'ihjse present. The ■ President; added that the members would bo grateful if .'•- Spencer would deal fiu-ther wi r n the topic at some future 'gathering of vlie club". In responding, Mr'Spencer signified his ■willingness to take up the subjectagain for the benefit of the members.