RADIO RECORD

Greymouth Evening Star, 6 December 1928, Page 8

RADIO RECORD

NOTES FOR USTENERS-1N

.(By

"Reception”)

TELEVISION,

AN IMPRESSED BEHOLDER,

Very differing opinions exist as to the real position which has been reached in connection with television. Most careful commentators are very guarded in their statements. They admit that within the severe limitations Which are obviously in force at tne present time the results are impressive. It is impossible to produce pictures more than about three inches square, mostly they are much smaller. It is impossible, they admit, to reproduce fine detail, except at enormous cost and with grave interference over a largo band of frequencies. The pictures are not brilliant. On the otherhand, one occasionally finds a real tenthusiast, as the following shows. The matter, received from The Post’s”’ London correspondent, is reproduced with the comment that it should not be regarded as more than a striking personal impression:-— Mr Baird, the inventor of television, seems to have gone forward in his researches. For some months, he has kept his secret closely guarded, but ti special correspondent of the Morning Post” had the privilege this week of witnessing a demonstration of' of tho process, and he is satisfied that, television has come to stay. In his account of tho experiment he says: —

Tho “televised” people were sitting In a studio three-quarters of a mile away from the little house near Olympia where I saw the’ performance. . 1 was taken to what looked like a fairly large vertical radio-set , With a' screen in the centre. The operator then tuned the picture in—turning a knob, just as one does in ordinary tuning-in —and gradually from a blur came up the image of a man who was seated. As the picture was tuned in, so did the the man’s features become clearer and sharper, until his hair, his eyebrows, and eyelashes and the curves of his mouth were easily discernible. •

11.-3 opened his mouth and said, “Good afternoon.” The voice sent over the other 'by wireless was clear, and one would have believed the speaker to be in tiie room.

Quito easily and quite naturally ho began talking about the weather and what he intended to do. At my side was a telephone connected with the studio in which he was sitting.

“If you want to talk to him, speak into the telephone,” the operator at my side said to me. “I can hardly believe this is true,” I said. “Sing me a song.” Without a moment’s hesitation I heard the reply. “Sure, I will sing you a song. What would you like?”

I looked at the man and he passed his hand over his forehead as if thinking of a tune, and then, with a pleased expression, he said: “I know,” and began a negro song. That song. had none of the disadvantages of the “talking” film, where the voice sounds as if it was passing through a husky gramophone. Imagine listening to the 8.8-C. when atmospherics are absent, and you will know how clear it was. And I could see him all the time. I noticed the way ho turned up his -eyes when trying to look pathetic, and I had to smile with him when he Suddenly endfed and broke into a hearty laugh. He must have guessed this, for he added: “I did laugh,, did I not? You must have laughed, too.” The best way of describing what the picture looked like is to compare it with a cinema film taken some ten years ago. Now and again there was a flicker —small lines would run up and down the glass and little pin pricks would appear, and the whole was slightly red in colour like the first proof of a studio photograph—but from beginning to end the face was always clear, and the features easy to recognise.

The performances had taken place in semi-darkness, although the performers were in daylight. I asked permission to pull the curtains aside and Expose the screen to the light. This I was allowed to do, but the picture remained just as clear. “Has distance any effect on reception?” I asked Mr Baird. “None at all,” he answered. “This experiment at three-quarters of a mile distant could just as easily be done across the Atlantic. Of course, if there is much atmospheric, the voice would be affected in precisely the same way as any radio voice thrown across the Atlantic would be affected.”

It was a memorable afternoon. I had taken part in a performance which is probably to be the forerunner of an achievement that will soon take its place in our everyday lives.

IN CANADIAN WILDS.

WIRELESS DEVELOPMENT. ,

The Canadian Government takes the greatest interest in the development of radio within the Dominion. All the Government radio stations on the Atlantic and Pacific coasts are equipped with radio direction-finding apparatus. This service is of the greatest value to mariners endeavouring to find a correct course in times of bad weather, when the ordinary system of dead reckoning cannot be utilised. The latest development in Canada is the erection of powerful radio'stations in the Arctic circle to assist in the development of the ntfw sea route via Hudson’s Bay and the Hudson Straits to tho Atlantic, the object of which is to shorten the journey and reduce the cost of transporting grain from Canada to the European markets. Radio was used in tlic> aerial survey as well as in Hie opening of the route in order that there might be tho fullest information. regarding the weather conditions and ice traffic. It is expected to have four powerful radio stations in operation in the Arctic circle early in 1930. Each station will have an officer in charge and three skilled operators. The staff will be relieved yearly. This is an illustration of how radio is assisting in developing the most northern parts of the British Empire. The United States Government has also a number of radio stations in Alaska. Radio stations operated on similar lines would, it. is contended by radio experts, do much to assist in the peopling and developing of tho northern parts of Australia.

RADIO LICENSES.

AUSTRALIAN INCREASE.

During last month there were more new licenses taken out by owners of radio receivers in New South Wales than in any other State of the Commonwealth (says a Sydney report) For the first time for two years at »east there was a decrease (amounting to 63 for the month) in the number of licensed listeners in Queensland. In Victoria at the end of last month there were 142,597 licensed listeners, as compared with 87,622 in New South Wales, but during the past •eight months the increase in the number of licenses in New South Wales has been more than double that of Victoria. The increase for the eight months was 13,554 in New South Wales, as against 6868 in Victoria. These statistics indicate that “saturation point” is being gradually reached in Victoria, whilst radio entertainment is becoming more popular in New South Wales. Another explanation of the increase in licenses in this State is’that during the past, six months the radio inspectors have been particularly active in detecting “pirates” who listen in to the entertainment programmes without paying a license fee for their receiver.

BURIED "AERIALS.” A great deal of nonsense has been talked of late in regard to aerials sunk in the ground instead -of suspended fr. th.? air in the common fashion. Many advantages have been claimed for these buried antennas, such as the elimination of static, avoidance of interference, and greater receptivity. Statements such as these require to be taken with the proverbial grain of salt. Experiments recently carried out in. America have definitely proved that buried antennas, no matter how arranged, are infinitely inferior to the crudest aerial erected in the orthodox manner. It is perfectly true that a buried antenna will reduce static, but unfortunately it will reduce the strength of the reception even more than it does the static. Exactly the same results can be obtained by snipping off a large portion of the regular aerial with a wire-cutter. Several types of these buried antennas have been placed on the market in America. The purchaser is given an instruction sheet that tells him to dig a hole and bury the can that accomplishes the alleged marvellous result, placing it a specified distance under the surface. Claims made for the devices are scientifically absurd. They seem to be limited only by the credulity of the victim purchasing the device.' An examination of these “antennas” showed that it consisted of a small can made of thin copper and filled with charcoal. To a point just inside the tipper edge was soldered the end of a twenty-foot length of ordinary enamelled wire. In other words the whole apparatus is nothing more than a ground connection. Whilst on the subject of antennas, a few remarks may not be out of place. Suppose an aerial is erected 30 or 40 feet from the ground, and 100 feet long. Such an aerial, plus a good “ground,” would give excellent results. Now, if you were to take that same amount fo 'wire and cut it into two pieces and string them parallel, a. couple of feet apart at the same height, you still would have an effective antenna. It 'would not, however, be as good as the 100 ft. one, and, in fact, it would be practically no more effective than a single 50ft. strand of wire. Coiling the 100 feet of wire into a spiral a few feet long would give about the same results as a single strand as long as the spiral. A buried antenna that consists of a can full of insulated wire cannot be more effective than a single piece of wire thrust into a hole of equal depth. It is apparent, therefore, that it is far better to plant flowers or vegetables, rather than to dig holes for the burial of antennas.

ELECTRIC STREET LAMPS,

LIGHTED BY RADIO.

A vacuum-tube transmitting set, using a small amount of power and operating on a wave-length of 7,500 meters, and five receiving sets responding to only one wave-length, control the street lighting system of Glen Falls, New York. This radio system, according to S. -R. Winters, writingin ‘Radio News,’ does not disperse waves in all directions, but concentrates its force along the electric power wires, and thereby a whole town can be illuminated by operating the transmitter only 15 seconds each day. With five seconds’ operation of the radio transmitter the street lamps are lighted; when the operator twists the “off” button in the power house the radio transmitting set operates automatically for ten seconds, and the lights are simultaneously turned off. The wired radio system involves the use in the power house of a small panel board holding all the radio transmitting equipment; the latter consists of two 50 watt vacuum lubes and a simple oscillator circuit. This panel board contains the electric switches or buttons which are designated as “off” and “on” respectively. Turning the “on” button places the radio transmitter in the circuit for five seconds. The result: Radio-frequency impulses are generated, these being fed to five wires leading to as many receiving stations, where radio apparatus is installed. The live receiving sets, one in each of tho five sections of the town’s street lighting system, control tho relay circuits to complete the lighting current supply. Transformers in each of the live independent units of the lighting system step down llio potential in the feeder wires Io the desired lighting voltage—llo—and the street lamps are then lighted. Al daybreak the operator at. the power house turns the “off” button on the radio-transmitter panel and the radio waves —in this case “wired wireless” —again pass over the feeder wires; they are picked up by the radio receiving sets and the relays, and, at tiie proper instant, the street lights are turned off.