For Prospects and Recruits

Radio Record, Volume I, Issue 15, 28 October 1927, Page 2

For Prospects and Recruits

By

M.I.R.

E.

In discussing one of the primary considerations in the purchase of a radio set in the last issue of this paper, it was: pointed out that it was an absolute recessity to choose a machine of standard make in order that satisfaction and service could be guaranteed and retress obtained in the event of trouble of any sort inaterialising. The recomwendation to purchase a standard ake was based on the fact that receivers operate according to laws well known to the initiated, and that in consequence infinite confidence could be placed in standard designs providing only the recognised agents, distributors, or sianufacturers are consulted when advice or assistance is necessary in maintaining the equipment at maximum efficiency. ‘This consideration is of such paramount importance that it has been judged necessary to repeat a definitior of it in order to emphasise its yalue- to potential buyers. It is hardly the function of this paper to give advice as to the best means of judging what makes of apparatus can be considered standard. Obviously, any types of equipment to be steered clear of cannot be named any more than it would be fair to state that this paper’s advertising columns represent all ,the makes or names of distributors who fall into the category just laid down. A buyer would, nevertheless, he well advised to consult the advertising columns of publications devoting space to the subject of radio, and after having made a selection of likely machines write or *phone the agents or distributors for further information, Invariably the get‘up of advertising matter and method vf dealing with inquiries will give an indication as to the service likely to be received at a later date in the event of a machine having been installed. The exercise of judgment along these lines. will invariably narrow further inquiries into more restricted channels. THE TYPE OF MACHINE. Having arrived at a perspective of the market, infinitely greater confidence may be enjoyed in dealing at first-hand with the representatives of the concerns vending the machines of interest. The next step is to decide which type is best suited to the individual task and pocket, Before passing to some semitechnical considerations which it is mecessary to discuss in order to arrive at a reasonably intelligent understanding of the subject, it is thought fitting to. make reference to the habit which has become almost ingrained in the pub-

lic in demanding a demonstration of , apparatus in their own homes. ears ago, when electric irons were hirst introuuced, electrical dealers were accustomed to having an ironing blanket and a piece of cloth in their shop im order to demonstrate that it was possible to actually iron by electriciry. The prospective buyer, howc.er, didn't ask-t.e dealer to send round an iron to hiy heuse to do the family’s weekly srouing for a week or two in order to be satisfied that it wouldn’t blow up or clectrocute the washer-lady. To-day any novelty of ironing by electricity is non-existent-in fact, any sort of an iron in use in a house where power is ayailable is looked upon as a sort of curiosity. WHO PAYS THE COST? ‘to-day the radio dealer is invariably in the position of the electrical dealer of yesterday. ‘The prospective buyer is not prepared to select a set out of the shop, but he wants one sent to his place and an aerial erected, etc., im order to make certain that the set will actually receive signals on his property. That is unreasonable enough from many standpoints, but then he wants the set left for sufficient time to apparently satisfy himself that it is a set which works every day in the week, and is not one which knocks off on Tuesdays and Fridays! last, but not least, he wants it for nothing, and the dealer has to take the risk of damage to apparatus and carry the burden of expense in time, and wear and tear of apparatus and accessories. Part of his job? Perhaps, but who pays? The public, of course, because the cost of selling radio under these circumstances is too high. A gramophone concern will sot make a machine and records available for prospective buyers to amuse themselves with while they are making up their minds; nor will a vendor of motorcars let a demonstration mode] loose for several days in the charge of 2) prospect, and incidentally supply him with petrol! Yet this is parallel] to

what is being demanded from the radio trade at present, The remedy and obviously simple procedure is to act on the advice given previously and decide on either one or several standard makes having models attractive both from point of view of advertised performance dnd price, and make the arrangements most suitable to dealer and the buyer] to try the machine out. The dealer will be able in the majority of cases to make arrangements in the best interests of the intending purchaser, such as an audition at hig place of business or some other spot where several models of the same or competitive makes can be switched on at will, thus enabling a comparison to be made which it would be palpably impossible to arrange at the buyer’s house, without very great inconvenience to everybody concerned. As a result of this a final decision may be made with ease and confidence at home, after a more Or less temporary installation of the thachine has been made, and the receiving conditions at the machine’s ultimate destination checked up. GUARANTEE OF SATISFACTION. Presupposing that the dealer concerned is handling his business on sound lines, he will be willing to guarantee satisfaction. If the results obtainable after a fair trial, extending over a weck, for instance, are not commensurate with the outlay, then the dealer should be invited to explain the position and make further recommendations. If continuing with receiver trials, it 1s necessary to take out a license (a shortperiod one will do in this case) should the trials extend over a week. The only reason that a receiver which passes satisfactory trials in one receiving posiion, and will not apparently repeat the same performance in another, is because the second receiving position is inferior to the first, due either to the mysterious vagaries of the ether or to electrical interference with the functioning of the receiver. he former is an uncertain factor, but in only isolated cases will it ever become of such importance as to cause

serigis trouble unless any particularly desifed station is consistently weak and unsatisfactory, whereas in another position this same station is strong, Where signal variations act to the detriment of reception in one direction they will act the oppositp "in another direction, and balance things up to the satisfaction of the listener, Any suspicion that a receiver is not acting up to scratch can be checked by the dealer by setting up a similar model alongside and changing the aerial quickly from one set to another, using equivalent valve and battery power. The same symptoms should show up on each, THE RANGE OF INTERFERENCE, Electrical interference takes two forms, the first being caused through natural, and the second through manmade means. Natural interference or "static" is cansed by electrical disturbances in the atmosphere and in the earth’s crust. This becomes audible in a multi-valve receiver in the form of crashes or frying sounds, and when at its worst is intensely irritating and annoying. It comes im storms and will vanish for weeks in the winter months, but is usually present to a slight extent throngh the summer months. However, static is only apparent when distant stations are being tuned in and a large amount of aniplification is being used in the receiver. With stations comparatively near, and especially stations of some ewer, static loses its ability to annoy ecause the relation of signal strength to noise becomes of such value that the signals easily win out and the static fades into an insignificant background of no more consequence than the needle-scratch of a gramophone. The point to be noticed by prospective buvers is that the signal strength of a distant station will always appear to be stronger under conditions clear of static than when there is a ‘‘noise’"’ background. lJowever, this question of static interference can be — safel shelved for a future article because it is a subject which should be given a comprehensive treatment or left alone. Suffice to say that it is not ee Be te *

_- ee entitled to the serious consideration that it receives.in the minds of intending purchasers of radio sets simply because any point, practically, in New Zealand to-day, is within range of at least one station which can deliver a signal strength sufficient. to beat even bad mid-summer static and the listenerin therefore has a programme always available, Those districts within a hundred miles of Auckland, Christchurch or Dunedin or within 256 miles of Wellington are definitely ‘assured of programmes throughout the year. Man-made interference comes principally from power or lighting mains and also from traniway wires, and is caused by the various electrical machines being fed by current from the wires setting up electrical impulses, which are radiated from the wires (just as @ wireless transmitter radiates its energy), aud are picked up by the radio receiver in the form of noises, which ean scarcely be described as pleasant in most cases. faulty insulators on wer lines will invariably cause intererence with radio reception in an area + surrounding the fault extending over several hundreds of yards on occasions, The remedy to these troubles lies in action by the power supply authorities, who are now fully alive to the desirability of keeping their distribution systems as free of trouble as possible, The dealer is in a position to take ithe necessary action towards coping with these troubles when they assume prominence, and it is only in isolated cases where the interference is of a very definite nature that a receiver is seriously affected. Summed up, the question of interference is only a sc¢rious one under any circumstances to those who have ambitions towards distant reception, and who are of the same turn of mind as tbe individual who wants every Saturday afternoon to be a sunnv one in order that he may always get his game of tennis. ‘True radio broadcast reception consists of tuning in a station whose signals are of such a strength compared to any interfering noises that the signals preponderate to such an extent as to render the interference relative in noise to a gramophone needle scratch. In terms of a year’s use of a receiver, there is really no snot in New Zealand where these conditions are not obtainable for at least $00 davs out of the 3635. and in the main centres this ts obtainable for 865 inciuding the 366th in Ieap Year,