NOTES FROM FAR AND NEAR.

Press, Volume LXVII, Issue 20274, 27 June 1931, Page 11

NOTES FROM FAR AND NEAR.

uv "M.ix • fjje wn'-'-r has often been asked for gjriee as to <ho best radio receiver to joy. Now this is a very difficult progm in Mjni'j v.avs and also carries a ggftaixt orii" int *>i responsibility. The jjjrariahie plan followed is to find out what pri< e the prospective purcj jaser ; s prepared to pay, whether he desires an elaborate cabinet, and Aether a gramophone combination is g]lo wiwittxi. The next point is to the types which appear to ' cover the iu « -is of the buyer and then gtcoinmend that the dealers be "approached for trials. It is always ggjggged that tho dealer should be told , Agt several types will be tried. . This •ggkes it easier when a set has to be MOt back and each salesman believes I his article lias claims that will hg\p to clinch a deal. i ■■■■■ • * » JiovF there is a great variety in taste vbeo it comes to what constitutes jgxl tone in a receiver, and when judging thia feature it is best to use «re set In conjunction with an electric rick-up on one's own gramophone (for caotf of have a machine of this description) if the set is not a radiogrtdophone. In this connexion it is unportant to use the same records, i&oasmg several that cover a wide HettjKe of musical and instruments, the piano, for instance, being a severe test lor an electrical reproduction. * * Just is important is tho choice of a aicbup. 'or what suits one audio intplitier will not necessarily suit auItber. The valves used and the neater also both play an important IJut in the results and poor fidelity U often caused by an unsuitable coniMaation. This does not apply, iti a radio-gramophone which is complete in itself, as the makers have settled this * /etiure when designing the outfit.

Host of us have heard sets belonging to friends and have certain. id,eas H f0 yrhfti. wtj would like, and tnis _as■atf# in making a judicious choice. * Xaov receivers include tone niters, "ftfeldi enable a change from a prepondmnce of base or treble, according to • The writer has hearcl several » rH' i '" w of different makes recently, there are some excellent ones availA friend y/ho has lately pur--■-'.dhMed a set,' and who has a first-class. : ' mt for music, and wher al»» has been gramophone "fiend!' for years, f-? aprewlues in the use of fibre or bamboo InjMfdles. He found the writer's advice fliws suitable, and took his time in test- ' . ffg different types of rdfceivers. A was used in each instance, and results show that the pick-uf> must ■ It changed for some sets to do justice .to them. He is satisfied that the bain4eo needle is better for faithful repro- ' lititon than is the steel needle. A less volume, but pure music and - M wear on the record. Quality was Jtfo buyer's first desire, and he is now J* wry satisfied owner. • * —. "-fl» pict-tin be uses is a B.T.H. and «6teMereveirer. Many people prefer motor, -as there are -isfllts in--some types of electricaliyHum is bad • in cuts, and this -is due the Voter feeding into the set. ' The inducber Dotor is usually froe from this defcet, and one which was recently tfeMTS with pride by its owner (an ? operator of a wireless station) is an '•' r atrcptioaally fine example of workmangnh i sWa' The turntable '. runs . absolutely V; MurieKfy.ffnd smoothly and there is Y. M tropble from hum; However,"it is k. bewccd the price which the average p| ;SB*a« prepared to pay for a'motor., . BM' ffa6aa» passing from tho. subject, the |j- of a receiver's capabilities on reception must not be forgotten,, this point depends upon whether is the first Considerntioh or not. in sensitivity and selectiv9&d if the ; ' reception ■ side atftia "feature 'desired, then tests igiper several evenings should, be given. PP&'aHMt be remembered that , even in MM* wieter time then is often a great is results on distant stations ||||&'«MMeative nights and often during few hmm' triaL Therefore, if pos-

sible, and if there is a hesitancy between two makes, try both on the same stations on the same eyening. Out of consideration for the salesmen, keep the machines in separate rooms when first delivered, but make the tests in the same room, as the acoustic properties vary considerably, at times, in different rooms. * * A new pick-up head, when connected to a gra,mophone and a pair of headphones, proved to be a dud. Examination showed that a small condenser inside the case, and shunted across the output, was defective. Disconnexion of one terminal of the condenser gave fair results, but there was a preponderance of the treble. The condenser would tend to by-pass the higher frequencies and was evidently placed for the purpose of reducing the treble and so artificially increasing the lower tones. A condenser offers a higher resistance to the baße notes and so' thefie would be reproduced at their full strength and the partial by-passing pf the high tones would act by weakening the latter, the effect being a greater proportion of base. This system is one way of overcoming a difficulty in a, cheap pick-up which does not of itself give the full value to the low tones. It pays to use a reliable pick-up. ■t * A new light-weight headphone which should appeal to the hard of hearing is now on the market. Its weight is one and a half ounces, has a diameter of less than two inches asd a thickness of thre&qui. iters of an inch. , Highgrade cobalt steel enables the magnets to be built with less iQaterial, and still have a strong magnetic field. It is. considered that this headphone should prove useful for pilots on aeroplanes as they will lit inside the helmet. v * * Chatting with one of New Zealand's foremost technical radio engineers recently elicited the statement that he considered that the midget receivers as a class do not givo nearly as pure reproduction as do the larger sets. Cramping of the parts is sometimes responsible for hum, tho power pack being a contributor in some cases. He believes that manufacturers are sorry that the midget , was ever marketed, as there is a big demand for them and competition compels makers to supply models. This Is detrimental to the sales of the ordinary types. The profits are also below what they should be when compared wjth those obtained,from the bigger machines, in proportion to the cost of production.' *

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There have been attempts in this j country to' exploit at least one station in the direction of advertising matter. The Post and Telegraph Department soon took steps to close down the offender. Advertising is strictly forbidden, though what can be termed "indirect" advertising has frequently been successfully put over the air in former days. * * The use of high frequency currents in medical science is being steadily developed. It has been found that when applied to a nerve trunk the process of pain transmission is slowed down and relief obtained, in some cases complete ansesthesia following an administration. Electric cutting needles fed with high frequency currents offer'a new field of painless surgery, which is also bloodless, since the needle automatically cauterises the wound. -* * "New Zealand Radio" is now incorporated with the "New Zealand Engineer," The same high-class paper is used, and the reader obtains reading matter of interest apart from the radio articles, and this will appeal to thoso who like to read semi-scientific news. BROADCASTING OPERA. GRANT OF £22,500. Details of the grants to the British Broadcasting Corporation, in the British Government Revenue Department's estimates issued recently, show that, apart from the main figures of £1,194,500 (compared with £1,060,000 in 1980), there is an additional grant of £22,500 "by way of a contribution to the cost of arrangements made between tlio corporation and the Covent Garden Opera Syndicate for tho production of grand opera. It_ is proposed, before any payment is made, to conclude an agreement with tho corporation under contributions will b© made to the corporation of £SOOO in respect of the quarter ended December 31st, 1930, and at the rate of £17,500 a year thereafter, during the currency of the agreement." This brings the 'total grant to the 8.8.C., to £l;217,0O0, an increase of £157,000 over the figures for 1930. In order to discuss several aspects of broadcasting, a public meeting of listeners will be held iri Auckland" on Monday next.