RADIO NOTES

Dominion, Volume 27, Issue 149, 21 March 1934, Page 13

RADIO NOTES

By

"ETHER"

CURRENT TOPICS It would be incorrect to say that Mr. Cecil Graves, the 8.8.C.’s Empire programme chief, ami his department aie really happy over immediate prospects. Put bluntly, Empire broadcasting is making no headway, says a critic in England. Trouble began at the outset with the choice of indifferent programme material on the assumption that the Dominions and Colonies would be so delighted to receive anything from the Mother Country during the experimental period that the programmes themselves would be of secondary importance. No greater mistake could have been made. ♦ * *

Space for a dozen or more new broadcasting stations throughout ths United States will .shortly be made available by the Federal Radio Commission by virtue of the opening or the 1500 to 1600 k.c. band for broadcasting services. These are the channels lying just above the upper limit of the present band of broadcast wave lengths.

The Marconiphone Company is now co-operating in the search for the Loch Ness monster. Hydrophones of the type used in the British Navy during the war to detect the sound of German submarines are now actually in use, but we are unable to state on what wavelength the monster oscillates.

Russia now ranks second in the world in the number of its broadcasting stations, of which it has seventythree, the United States heading the list with 585, according to a new “Directory of Foreign Broadcasting Stations” just compiled by the United States Department of Commerce. Canada is third in the list with sixtythree stations, Australia has sixty, Cuba fifty-seven, Mexico fifty-three, Argentina thirty-five, Uruguay thirtythree, New Zealand thirty-two, and Sweden thirty-one. Unfortunately, the figures are a very unreliable indication of any country’s broadcasting prowess, for tlie stations listed include anything from a 1000 k.w. transmitter to one working on less than 500 watts. If this were not so, Great Britain, with her twelve stations, would cut a sorry figure against Cuba with fifty-seven. China, it seems, holds the record for the lowest power, there being a broadcasting station in Shanghai working on~ half a watt.

§ix languages are now used at the microphone of tlie short-wave station, PHI, at Hulzen, transmitting on I(|.BS metres. This famous station, the successor to Eindhoven, has broken a silence of two and a half years. Transmissions, although intended primarily for the Dutch East and West Indies are being picked up by short-wave listeners all over the world. The languages used are Dutch, Malay, English, French, derman, and Spanish. Transmissions are on Monday, Thursday, and Friday, from 12.30 to 2.30 p.m. (G.M.T.). and on Saturday and Sunday from 12.30 to 3 p.m. (G.M.T.).

Hayiiig been accustomed to the straightforward English of “The Dominion,” you would find the reading of some of the American radio papers a very difficult task. In fact the ambition of many American journalists is to invent a thousand and one ways of avoiding calling a spade a spade. Now listen to this: "Totten Supes Spielers in Chi.N.B.C. Switches.” That is American for “N.B.C. staff changes in Chicago have made Mr. Totten a supervisor of announcers.” “RADIO RECORD” The outstanding feature of this week’s “Radio Record” is a brightly-written article giving “Plain John Smith’s” .opinions of a week’s radio programmes. As the foreword to the story says, it is the plain John Smiths that radio should eater for —not the highbrows, nor the jazz fiends, but for the ordinary man, who turns on the radio just for "a pleasant background of noise.” Another interesting story is the first of a series dealing with the use made of radio by the police force of America, and topical articles on Lancashire and the opera “Carmen” —suggested by coming programmes —arc also well worth attention. As usual, the regular features are bright and interesting, the Wellington notes containing an important announcement of a radio exhibition which is to be held here very shortly. Film notes, a witty contribution from Ken Alexander, and the usual women’s notes and recipes, together with the programmes for Australian and New Zealand stations for the coming week, complete an interesting issue, GANGING When using a set with a number of tuned circuits and ganged condensers you will sometimes find that even though you get the different circuits properly adjusted for one particular wave-length, or one particular region on the dial, they may go out of adjustment when you tune in to a point some distance away. The aerial circuit, for instance, sometimes goes quite out of tune with the other circuits. This can be got over and the tuning adjusted, as a rule, by putting a condenser in the aerial lead to the first coil; the condenser may have a value of 0.0001 mfd., while sometimes a smaller value does the trick better. You may find that this condenser will have an effect on the strength of tlie signals—it may reduce tlie strength—but as a rule this should not be serious, and you will probably find that you get, on the other hand, an improvement in selectivity. SCREENED LEADS In order to prevent Ihe pick-up of hum and other forms of interference it is sometimes nn advantage to run loud speaker extension leads with screened cable, the metallic shielding of which is, of course, earthed, preferably at more than one point. But it should be borne in mind that screen extension leads are bound to have a fairly high capacity, and so there Is a risk that high-note loss may take place; accordingly, screening should not be used indiscriminately. It should only be employed when limn is troublesome and when the addition of screening effects a definite improvement.

It is quite n simple mutter to use two loudspeakers together ami to adjust not only the relative loudness of the tw6 but also actually the quality of the tone. An arrangement for regulating the relative loudness of the sounds is as follows: —- The two speakers are connected together in series across the output of the set, and then a resistance is connected also across the output of the set, that is, in parallel with the two speakers, this resistance—or potentiometer—having the slider connected to the common point of the two speakers. As the slider is'shifted it is possible to bring out the upi>er register or the lower register.

WHAT TELEVISION MEANS Seeing at a Distance “Television” means “seeing at. a distance,” or “seeing afar off.” Now, at first glance it might seem that this is exactly what we do when we look through a telescope, but actually there is an important instructive difference, says a writer in an English journal. The telescope takes in light from the distant scene and assembles it into an image which is present continuously and is complete in every detail at any given instant. In television this has never been done. In all the systems which are. capable of practical use by radio it is necessary to transmit the picture one tiny piece at a time, these minute fragments being sent out one after another in rapid succession. It is done in an orderly way, so that by degrees the whole area of the picture is covered. Now, when I say “by degree” I don’t mean “slowly.” On the contrary, the process must be so quick that a complete set of pieces to make a picture of the scene which is being transmitted takes only a fraction of a second to send out. THE GRAMOPHONE AND BROADCASTING An English Critic’s View It is interesting to see that the question of broadcasting records is a matter of controversy not only in New Zealand, but also in England. The following extract from the “Wireless World” may interest listeners Any critic who argues that the 8.8. C. should discontinue the use of recording as an adjunct to broadcasting is proposing to deprive broadcasting of one of its most important assets. The record and other artificial devices are used extensively for the production of outside noises and effects, many of which it is difficult, if not impossible, to reproduce on the stage. Broadcasting should make every legitimate use possible of this aid, and it must be left to the good sense of programme producers to sec that it is not abused. HAND CAPACITY When hand-capacity troubles are present on a short-wave set they can often be cured by removing the earth lead completely. This holds good mostly in cases where a long lead has to be used. Another method of curing them, however. is this; Generally the earth lead comes into the room via a corner of the window. Instead of connecting it directly to the set, join a length of stiff bare wire to the point of entry of the lead, and take this straight down to the floor, anchoring it to a screw. Now take a flexible lead from the earth terminal of the set and terminate it with a crocodile clip. By sliding this up and down tlie wire from the window to the floor it is often possible to find a point at w’hicli hand-capacity effects will disanpear completely.