Notes and Comments

Radio Record, Volume IV, Issue 14, 17 October 1930, Page 9

Notes and Comments

By

SWITCH

IAS usual, running descriptions of the Caulfield Cup, on October 18, and the Melbourne Cup, on November 4, gare to be broadcast throughout Australia by the "A" class stations and by shortwave transmission. Melbourne Cup Day is a public holiday in the Victorian capital, and many thousands who do not attend the races go picnicking for the day. Portable wireless sets are taken on these outings, and the broadcast running description of -the Melbourne Cup is heard on the beaches and in many a picnic spot in the bush, Me: CLAUDE P. GRY, of Shannon, one of the "long-distance radio aces" of New Zealand, still pins his faith to his battery-model receiving » set, which, he states, on any night com- * oves more than favourably with A.C. models. Recently Mr, Grey received a printed permit from broadcast station KGMB, Honolulu, offering him free use of that station "to promote education, science, music, agriculture, spiritual and fraternal subjects when they can be broadcast without prejudicial intent, mercenary motives, and for the betterment of the public as a whole.’ Rumour hath it that Mr. Grey is preparing an address on ‘"The Polemics of the Athanasians" for de- livery from the Honolulu station. Perhaps! "QCREEN GRID" (Opunake) writes: "J notice in your last notes mention of a station between 8AR,. Melbourne, and 4YA, Dunedin, which you had been unable to identify. I heard this station fairly distinctly on 4a Thursday night (September 18 I think was the date), but I could not hear the announcer at all well. However, I thought I heard the word ‘Columbia,’ so came to the conclusion that it was CFCT, Vietoria, British Columbia, as the wavelength -(635 ke.) coincides with the listed wave-length of that station. ‘I also heard a station ‘which seemed to be putting over a similar programme (musical) on 690 ke. (just above 6WF, Perth), which I think may have been CFCN, Calgary. The strength of these two stations seemed to be similar, The night in question was a wonderful one for‘ reception. I listened from about midnight until 12.30, and heard no fewer than ten different Japanese stations. I was unable to wait. and hear all the call signs, but the ‘usual ones’ are: JOAK (865 ke.), JOFK (850 ke.), JOGK (790), JOHK ° (770), JOBK (750), JOCK (8380), were operating, and in addition stations were operating on 800 ke.;.900 ke., 870ke., 890ke. These four-letter stations are apparently not listed. One other Japanese station on 970 ke. was evidently not open on that evening. I.also heard COMK and GOW very distinctly." LISTENERS from time to time must have noticed a rather flagrant flaw in ringside descriptions of wrestling matches both in New Zealand and Australia. Many an excellent description of these contests has been spoilt by the unnecessary ejaculations or superfluous exclamations of the gentlemen at the microphone. Nothing could be more amateurish than such exclamations as "Oh! Ah! What do you think about that?’ ete. etc., and then also the loud guffaws of an announcer when the wrestlers amuse him with their antics. It is all a matter of a little self-control

. . ’ { and commonsense. In the theatre where the audience may be screaming ‘with laughter the performers manage to continue without joining in the merriment. Wrestling announcers should practice self-control in such a case. A commentator on wrestling matches in Sydney is: the worst offender. "PEST" (Kelburn) writes: "I have an idea that my a.c. set is pick~ ing up parasitic noises from the house-,

hold electric:mains. Is there any method of blocking this?’ The source of noise mentioned by "Test" is uncommon. A method of mitigating the trouble is to connect a filter consisting of a 150-turn coil in series with each mains supply lead to the receiver. Further improvement could be obtained by connecting across the mains side of the coils a pair of 2 mfd. capacity by-pass condensers in series, and connecting their midpoint to earth. The job, however, should be entrusted only to a certificated electrician, who would enclose the whole in a danger-proof container. THE majority of listeners show great interest when news comes 'to hand of some revolutionary development in radio reception. Many false alarms, however, have occurred during the past three or four years. The latest announcement comes from Germany, where an inventor claims to have perfected a valve which requires no A battery for its operation, depending. upon the action of a substance when light is shone upon the valve. This

would be a great boon to New Zealand country listeners who reside in remote places and have to carry their A batteries long distances for recharging. The new valve would also be extremely acceptable for portable receiving sets. The cost of A batteries, wet or dry, is also a factor in rendering such an invention as this new valve most welcome. "Switch" hopes the news is authentic, for, no doubt, the American and English valve manufacturers would make a bid for manufacturing rights. HE discovery that certain substances when exposed to light will emit electrons is not new. Fifty years ago a German experimenter, Hallwacks, announced this discovery. Long before commercial broadcasting was evolved selenium cells were available for experiment. The modern photoelectric cell used in some talkingpicture systems and in television is an adaptation of the 50-years-old discovery of Hallwachs. Now the invention of a radio valve which works without an A battery is merely a further develop-ment-of the same discovery. A WELLINGTON radio dealer informs "Switch" that the establishment of an Empire shortwave super-power broadcast station in the

near future has aroused considerable interest in shortwave reception. He has received quite a number of orders for shortwave sets, and is devoting a large amount of time to building them. As soon as this high-powered shortwave station is on the air in HPngland, he is convinced that there will be a veritable boom in shortwave receivers. "TH Australian Government has decided to establish a supplementary station at Crystal Brook, South Australia, next year, The station wili broadcast its own programmes, but on special occasions will be linked up by Jand-line with the Commonwealth "A" stations. Listeners have been agitating for the new station, as 5CL, Adelaide, is not well received in ‘the Crystal Brook district. "QWwiItcH" expresses thanks to "H.M.W." (Christchurch) and the Wellington correspondent who forwarded particulars concerning the Beverage aerial, The writer envies those listeners who reside up-country and have plenty of room to erect one of these aerials for experimental pu--poses. Placing the aerial along the top of a fence seems to provide a solution of the expense problem. An aerial over 280 yards in length, apart from the cost of insulators and wire, is rather too expensive if posts have to be erected to support it properly. A WELLINGTON listener who has employed a screen-grid valve for a considerable time in his short-wave reéeiving set gave the writer a demonstration of its powers a few days ago. The set performed surprisingly, and it was easy to operate. The owner contended that the screen-grid valve is all that has been claimed for it, but in many instances it has not been fairly treated, hence many failures to "deliver the goods." Success is sometimes achieved," he stated, "by varying the screen voltage of the valve." The higher the screen voltage for a given plate voltage the lower is the impedance of the valve, and, therefore, the smaller its magnification factor.