THE RADIO WORLD

Southland Times, Issue 19897, 16 June 1926, Page 14

THE RADIO WORLD

NEWS AND NOTES. (By “Reflex.”) In reviewing the past week it must be admitted that reception has greatly improved. In conversation with “Reflex” a number of radio men in Invercargill expressed the opinion that in view of the non-interference of the atmospherics, the New Zealand and Australian stations have been a pleasure to listen to. However, the feeling seems to exist that the New Zealand stations as a whole are too weak to compete with the Australian ones. It is stated that the tone, volume, and general organisation of the latter are much superior with the result that the owners of valve sets are giving more attention to them. This state of affairs is decidedly unfair to the users of the crystal, who are perhaps the biggest body of listeners-in holding licenses in the Dominion. 4YA Dunedin has not attained the standard of efficiency that was set during the Exhibition period by VLDN. It will be that the latter station in its early stages was not at all satisfactory to listeners-in, so hopes are entertained for an improvement, before long in 4YA. The Brisbane station, 4QG, is still the most popular station on record. On Saturday evening the writer listened to some splendid dance music by Miss May Dobbyn’s vice-regal orchestra relayed from Lennon’s Hotel. Switching over to Melbourne the results of the Test Cricket match were received plainly, as well as decision of the Weber-Yokel wrestling contest. SCL Adelaide is coming into the fore with some very interesting programmes. The strength is apparently adequate for the local fans over there but I don’t think that New Zealand receivers bother with it a great deal. Some wonderful work is performed nightly by the Sydney police wireless patrol. A high-powered car is equipped with a radio receiver and with a police personnel moves unobtrusively about the city, but is at all times in touch with its headquarters and able to speed, at a moment’s notice, to any place where police are needed. The Melbourne police department also has a radio patrol, a very smart arrest having been made by its assistance quite recently —a burglar being caught before he had gone a mile. It is announced that a Japanese professor of seismology has invented a piece of apparatus which will give warning by wireless of impending earthquake shocks. Preliminary tremors too faint to be felt are translated into sounds which are amplified and automatically broadcasted. At the same time an announcement is made of the general direction of the disturbance. On Sunday night we had the impression that 4QG had installed a similar piece of apparatus at Brisbane. However as it turned out the sounds emanated from a red hot revivalist meeting conducted by the famous Gipsy Smith.—From a Christchurch paper. Distortion may be caused by several things. First over-regeneration will most certainly cause the signals to become mushy and the regeneration control should be moved back or the detector tube rheostat slightly turned down. Distortion is also caused, as previously stated, by wrong C battery bias. Too great a value will cause distortion together with loss of signal strength, while too small a value will not impair the volume, but will cause distortion, making the speech muffled. It should be recognised that no set will give distortionless speech if connected to a 30/- loudspeaker. Nearly every horn type loudspeaker on the market to-day distorts the speech to some extent, and this applies from the highest to the lowest priced, the latter, of course, being the worst. The cone type loudspeaker has come to stay and there is little doubt that within the next 18 months the horn type will disappear from the market. The cone type speaker appears to amplify all notes evenly, with its small diaphram, responds either to high and low notes. If therefore you have one of the small cheap speakers now on the market, do not blame the.receiver before you have tried a better speaker. The newly-appointed honorary Wellingdistrict assistant radio inspectors, Messrs Campbell, I. M. Levy, T. H. Meegan, and W. Roche, have received their detailed instructions from the P. and T. Department. The new appointees are honorary officers of the P. and T. Department, and as such are vested with full authority under the radio regulations. They have right of entry into any radio licensee’s premises on production of the written authority with which each has been supplied. Any licensee unduly delaying or obstructing their admission renders himself liable under the radio regulations. The P. and T. Department insists that the provisions of the regulations with regard to prohibited circuits must be observed strictly to the letter. So-called “club radio inspectors” have absolutely no authority from the P. and T. Department and cannot be recognised. Only the Department’s radio inspector, assistant radio inspector, and the Department’s four honorary assistant radio inspectors have any right to demand admission to any radio licensee’s premises. These officials will present their written authority in every instance. Long before wireless was as popular as it is to-day accumulators were used for ignition systems on internal combusion engines. When used for such a purpose the discharge was, of course, intermittent, due to the trembler action of the sparking coil. It was found that the ordinary capacity of an accumulator was doubled when used for this purpose. As an example, a cell having a capacity of 10 ampere-hours, when discharging continuously for 10 hours, at 1 ampere, could be discharged for twenty hours at 1 ampere, on an ignition system. This led to the rating of accumulators in terms of their “ignition capacity,” and the example quoted above was known as a 20 ampere-hour accumulator. The discharge demanded from an accumulator when used to light valve filaments is, however, quite different from the ignition system, and it is the continuous discharge rating which interests us. Thus in the above example the cell would only have a capacity of 10 am-pere-hours when used on a radio set. Readers should be very careful, therefore, when purchasing accumulators to specify the capacity in “actual” ampere hours, it being remembered that the ignition capacity is approximately double the actual capacity. Prior to his recent successful demonstrations in England of sending photographs by wireless, Captain R. H. Ranger, of the Radio Corporation of America, reviewed the progress that has been made in radiophotography during the last two years. He said that three transmitters and receivers were working in America between New York and San Francisco, but they were still more or less experimental, though from Honolulu to San Francisco they were working commercially on occasions. Captain Ranger showed specimen pictures sent by radio. These resembled the half-tone block in their building up, in that the picture was produced by a series of dots, close set, and thick or fine, according to the depth of tone required. A feature of Captain Ranger’s apparatus is that the light and shade do not depend on the intensity of the received signal, as in sotne systems, and consequently interference by atmospherics is largely eliminated. With an eye to newspaper requirements, the apparatus has been designed to produce negatives or positives at will and in such a state that these could be sent direct to the engraver, and so save time. A possibility of the system—it is not commercially practicable yet—is the transmission of pages of MSS, instead of transmission word b, word. Actually messages in Japanese have been sent by the picture method. One picture which was shown as an example of freedom from atmospheric interference, had been sent from New York to Carnarvon, and automatically relayed back to the same room, in New York from

which it had been issued. It was received back in a, quarter of a second or less, and examination showed that it was a perfect reproducible picture. The following schedule showing the power, wave-length, and days of transmission of the New Zealand and Australian broadcasting stations is published:— IYA—The Radio broadcasting Company of New Zealand Ltd. Auckland. Power, 200 watts; wavelength, 350 metres. Transmissions on Monday, Tuesday, Thursday, Friday, 8-9, 9.15-10.15 p.m., and Friday 2.30-4.30 p.m. IYB—La Gloria Gramaphone Company, Auckland; 50 watts; wavelength 275 metres. Transmits Sunday 7.10 p.m. IYC—N. C. Shepherd, Whangarei; 15 watts, 250 metres. Transmits Monday, Wednesday and Friday, 8.10 p.m. IYD—L. R. Leith, Auckland; 50 watts, 330 metres. Transmits Wednesday, Saturday, 8-10 p.m. Saturday afternoons where possible. 2YF—Palmerston North Radio Club, 5 watts, 200 metres. Transmits Monday, Friday, 7.30-9.30 p.m. 2YK—Radio Broadcasting Company of New Zealand Ltd., Wellington; 120 watts; wavelength 273 metres. Transmits Tuesday, Thursday, Friday, Sunday, 8-10 p.m. Also Friday afternoons. 2YM—The Gisborne Radio Company, Gisborne; 500 watts; wavelength 260 metres. Transmits Tuesday, Thursday, B-10 p.m. 3AC—The Radio Broadcasting Company of New Zealand, Christchurch; 50 watts; 240 metres. Transmits Tuesday, Wednesday, Saturday, Sunday, 8-10 p.m., Friday, 6.45-7.15, 8-9.30 pun. 4YA—Radio Broadcasting Company of New Zealand, Dunedin. Power input, 750 watts; wavelength, 380 metres. Transmits Monday, Wednesday, Friday and Sunday. The Australian stations transmit day and night, including Sunday. Melbourne, 3LO, 371 metres; 3AR, 484 metres; 3UZ, 317 metres. Sydney, 2FC, 1100 metres; 2BL, 353 metres; 2KY, 280 metres. Adelaide, SCL metres; SDN, 313 metres. Brisbane, 4QG, 385 metres. Perth, 6WF, 1250 metres. Hobart, 7ZL, 417 metres. In answer to a correspondent who wanted to know at what readings on his condenser dials he may expect to hear certain stations, “Proton,” writing in the Lyttelton Times, gives the following information:— Obviously the question cannot be answered without knowing some of the stations he does hear and at what condenser settings. There is no reason, however, why anyone should not prepare for himself a chart which will enable him to find any station within range of his receiver. This operation, which is called “calibrating,” is quite an easy one, and is here described. Obtain a sheet of squared paper such as engineers and schoolboys use for “graph” work. On the left-hand edge mark out a scale of wavelengths from 240 metres to 490 metres, and on the lower edge a scale of condenser readings from 0 to 100. Some care should be taken in choosing scales suitable for subdivision. Draw horizontal lines across the page through the following points on the wavelength scale, and on each line print the name of a station as given below:— 240 3AC—Christchurch. 263 TUW—Bellevue, Sydney. 275 FfB —Auckland. 280 2KY—Trades Hall, Sydney. 295 2YK—Wellington. 297 2UE—Randwick. 350 IYA—Auckland. 353 2BL—Broadcasters, Sydney. 371 3LO —Melbourne. 380 4YA—Dunedin. 385 4YG—Brisbane. 395 sCL—Adelaide. 410 7ZL—Hobart. 484 3AR—A.R. Co., Melbourne. This list may, of course, be supplemented by the addition of other stations whose wavelengths are known. Now tune in three or four stations easily located and draw vertical lines through the condenser settings found. Mark the intersections of these vertical lines with the horizontal lines through the stations heard. This will give three or four points on the calibration line. Draw an even curve through these points and extend it across the page. To find any station, note where the horizontal line cuts the curve and run down vertically to the condenser scale. If more than one condenser is used the operation must be repeated for each. As an example of the kind of result one may expect, the following settings were found and the stations heard on a standard neutrodyne, all three condensers giving practically the same reading : Condenser Station. Setting. 3AC 13.5 2UW 16 2KY 18 2UE 20.2 2BL 30 3LO 34 4YA 36.5 4QG 38 SCL 41.2 7ZL 46 3AR 59 The "whole of the above operations including drawing the curve and picking up the stations occupied half an hour. TELEVISION. MR HUGO GERNSBACK’S VIEWS. “When I speak of Television,” says Mr Gernsback, in Radio News, “I do not predict a novel type of radio set, but rather the creation of a device which can be attached to your radio set. It will be similar, in its relation to the present radio set. to the loud speaker which can be connected to your set.” Mr Gernsback then explains it will be quite possible to see as well as hear a singer at a broadcasting station through transmission on the same wave to which the receiving set is tuned. The sounds at the broadcasting studio are changed to electrical impulses, which are superimposed on the “carrier” wave to ultimately reach the receiving station. It would be quite feasible to superimpose on the same carrier wave light impulses which would in no way interfere with the sound impulses owing to their extremely large difference of frequency. “I have pointed this out,” Mr Gernsback continues, “to bring home the point that, when television is finally brought about, it is quite probable that to-day’s radio set will be adapted to this new purpose; and that it will* be possible to connect a television attachment right to your present set and thereby see what is going on all over the country while you are enjoying the programme. Not only will it be possible to see the entertainers at the broadcast station to which you tune in, but everything that is broadcast for sound only, to-day, will be broadcast by ‘remote control’ for television.” Mr Gernsback states that inventors of the entire world are racing frantically for the goal, because they realise that in television they will Jiave created a great new emancipator, much greater than the telephone or radio communication itself. He. estimates that television will almost surely be perfected within the next two years or sooner. For a long time to come, transmission will only be in black and white, giving an effect similar to that seen in motion pictures now. Colour transmission will come later.”