Radio Review

Evening Star, Issue 20132, 23 March 1929, Page 20

Radio Review

Flashes from Everywhere.

—[By “HENRY.”]

THROUGH THE STORM. 4YA’S NEWS SERVICE. In addition to what appeared in tho ‘‘Evening Star’ on Tuesday, Station 4YA kept listeners well informed as to tlio effects of the day’s rain, < Almost after every item on the musical programme the announcer came forward with some information as to what damage the rain was doing in various parts of the city and suburbs. Both the Police Department and the listeners co-operated with 4YA in issuing warnings to motorists and to the public generally. It was indeed a welcome service, 4YA, and was appreciated by everyone the writer has spoken to. The Broadcasting Company’s station at Wellington, 2YA, was, unfortunately, not in the position to give its hearers the same sendee as its sister in Dunedin did, for the aerial towers were brought to earth by the wind in the day tune, and the station opened up at night as best it could. However, it did’ not get very far before it was forced to close down for obvious reasons. If the station had been working as usual during the evening it is possible that it would have been able to broadcast similar information to 4YA. On that night the St. Ki lda_ Band was to provide the major portion of the programme. Although a nnmlier of the members of the band were unable to leave their homes, _ what sounded like half the band carried on in the studio until it was plunged into utter darkness. That put a stop to the band items, hn the various supporting artists continued with their part of the entertainment. Long after the usual hour of closing 4YA was still on the air _ broadcasting gramophone selections in between announcements regarding train blockages and Hoods in different areas. MORE PRAISE FOR 4YA. Much has appeared in these columns of late against Station 4YA, but, as was said previously, give credit where credit is due The announcement that the exponent of the banjo-mandolin, Kamo, was engaged last Saturday evening excited interest in wireless circles. Listeners who tuned in to the local station were treated on that night to fifteen minutes of sparkling fare, and the man with Hie “lightning fingers” quickly established his right to the title. The versatility of_ Kamo and the capabilities of the banjo were fully demonstrated in the opening descriptive piece, ‘Down in the Forest. ’ With remarkable rapidity ‘Chimes of the Bells of St. Mary’s followed, after which the artist imitated the bagpipes on the banjo and also two Chinese gentlemen arguing. On Sunday night the station secured the services of Mr Arthur Hirst, who has built himself a great reputation in other lands in the world of music. Mr Hirst did not try to lecture or give an address, but' .simply gave a short talk regarding music. This was greatly appreciated. THE NEW LICENSES. All listeners should renew their licenses without delay. Remember, there is but a week left to do so—iu fact, oiih - six days for nothing can be done in this respect to-morrow. The nearest postmaster or radio inspector, as stated in these columns previously, will bo pleased to furnish details regarding the procuring of the new licenses. Above all, do not forget that anyone found with a receiving set in his possession without a license will find himself in hot water, so to speak, for the department will not hesitate to take action. Therefore* it may lie repeated that licenses should be renewed next week, A word to the purchasers of new sets will not be out of place. If you buy a receiver to-day it must be registered to-day. Some people seem to be of the opinion that a new set does not require registering until the beginning of the new year (April 1), but such is not the case.

A FEW TIPS. Perhaps readers will find in one of Urn following paragraphs just the information he is searching for: German silver cannot be soldered with lead without showing a difference in colour. The following formula obviates this difficulty -.—Silver, one part; brass, one part; zinc, one part. Melt in the ladle, stir, pour into the mould, and cool. The llux for the foregoing is borax powder. Close analysis of several receivers known for their lack of background noise shows that this result is obtained by extensive by-passing, using good, ample condensers for the purpose, if each B battery load is thus treated the so-called stray battery noises will mainly disappear. It is .sometimes hard to locale the screw holes for condensers and other instruments to be mounted on a panel without the aid of a drilling templet. Here is a simple way to locate the position for these poles: Locale and drill the hole for the centre shaft of the condenser, 'rhea place the instrument on the panel with the shaft protruding through the hole and rest it in exactly the position you wish it to occupy. .Sprinkle- a little while powder or Hour around the screw bushings, and then carefully pick up the condenser without disturbing the panel. The powder will form little circles, the ventres of which may bo marked with a sharp centre punch. It is poor economy to connect new mill old dry ce.lls in parallel. 'Phis (.ends to ruin the good ones, and will do the old ones no good. Little harm may be done if tlio two cells arc connected in series, however. In a -parallel connection the positive terminals are connected to positive and negative terminals to negative. In connecting in series, positive terminals arc connected to negative, and the end positive and negative terminals are connected to the output device that is being supplied with current. When wiring a receiver care must he taken that the “ loop ” end of wire that goes round a. binding post follows the screw thread. With few exceptions all binding posts are threaded with a right-hand thread. Therefore tho nuts are tightened to the left or clockwise. It is a good idea., when making a loop in the end of a wire which is to be placed on a binding post or a screw, to bend the loop in a clockwise direction or to Iho left, so that Hie wire will not be twisted out from under the nub when it is tightened. Always make tho loop in the same direction that the nut tightens in. Jacks and switches' are important, and should be looked after occasionally. Try a ping in tho jack, and see that there is not too much play. A poor contact will cause a lot of trouble alter tho set has been iu operation for some time. The springs should be tested in the same manner as a socket. There are several makes of jacks on tho market, many of them good, but in _n. short jack special care should he paid to the springs. In switches made in the form of jacks the spring should be rather heavy to get a good contact. In the closed types dependence will have to be placed on the name of the maker.

NO MO UK “HAM” NOTES. At a recent meeting of the N.Z.A.R.T. the “ Main ” notes that appeared in the ‘Star’ on Saturdays were discussed, am! the opinion was expressed that there was not enough interest hero to warrant their publication. It that is the ieoling among the amateurs the notes will cease from now on. LISTENING AT LA HERO USE. Overlooking Botany Bay, on the lieiiriits of La Peronse, stands the most important and largest wireless receiving station in the Southern Hemisphere. Of the most modern design the equipment incorporates the latest ideas in commercial receiving apparatus (writes a radio contributor to an Australian paper). From a network of stations throughout the world, traffic is received there. Messages from slops, stations in the Pacific and Indian Oceans, and from the coastal radio stations on the southwestern seaboard of Australia also come there, and two-way wireless telephony is maintained between La Pe rouse and the trawlers operating off the New South Wales coast. The latest news of the world is also received there from the Rugby highpower station, while reception is effected of broadcast programmes transmitted from English. American, and Continental high-power stations. The enormous ranges at present attained by short-wave working is demonstrated by the reception at La Perouse of experimental communications from short-wave stations in .Britain and Europe, the United States, and Canada, Africa, Asia, and the Dutch East .1 ndies. La Peronse maintains communication with all tjie short-wave stations in the Pacific, including Rabaul. New Guinea, Suva in Fiji, Noumea in New Caledonia, as well as San Francisco. Effective communication is also kept up with ships’ stations, equipped with short-wave apparatus, crossing the Pacific and Indian Oceans. The system of centralising wireless activities, developed by Mr E. J. Fisk, managing director of Amalgamated Wireless, Ltd., has resulted in the establishment of three centres in the State—the transmitting, at Pennant Hills, the receiving at La Peronse, and the control centre in York stieet, Sydney. Under the old system it would have been necessary to have a separate site for each of the nine commercial services at present conducted from Sydney. Operators are located at only La Perouse and headquarters, the staff at Pennant Hills being comprised of engineers alone. The operating efficiency of all the services has been greatly improved by the new arrangement, apart from the economy both in equipment and personnel. The visitor to La Peronse sees only a small building and a few masts, but the operator inside the building secs one of the ■wonders of modern science—a receiving station with gigantic electrical “ears,” able to detect the smallest vibration, and to read, instantly, its message, whether it has travelled, one or ten thousand miles.

ONE OE THE ESSENTIALS. KEEP THE RECEIVER CLEAN. 11 every listener were asked whether he takes the trouble to keep his receiver clean or not how many would he able to truthfully answer “I do'”? The majority or the minority? Often enough the complaint is heard that when the set was first erected it gave first-class results, but that it now appears to have gone off and that signals are not nearly so good as they used to be. Often new valves and batteries have been purchased in the hope that things would return to normal, but without success. All this expense and worry might be avoided if a brush and a duster were used freely on the gear. Few persons seem to realise how much loss is introduced into a set through dust. If a condenser be used as a- coupling i between the plate of one valve and the grid of the next in a. resistance capacity unit it is essential that the condenser bo very sound and able to stand quite high voltages, as it not only has to bypass certain frequencies from the plate ,of the valve to the grid of the next, but must he able to withstand and totally prevent the “R ” voltage battery from reaching ' the grid of the following valve. Should the condenser show any slight leakage, a very high positive bias will be placed on the grid, and thus prevent the amplifier operating as it should, and if the leakage is big enough it will totally stop operation. Two or three tests are often made before it is noticed that the pitch which is used to fill up the condenser and rssist in holding the terminals in place looks dirty and dusty. Discarded condensers are retrieved and given a slight wipe over with the finger. Tested again, each shows that it was in perfect condition and held its charge quite well for a considerable time. , This brings home to me more than anything has ever clone the necessity , for maintaining the apparatus in a state of thorough cleanliness, both inside and out, and it Ts advisable for those who have apparatus which appears to have gone off to try the effect of a thorough cleansing, not forgetting such places as between the valve „ sockets,, the valve pins themselves, be- ;; .-tween the ; i ondenser Vanas, and -top of the “ A ” and “ B ” batteries.

** Henry" will bn pleased to answer any questions through this column relating to the fascinating hobby. Each correspondent must sign bis name and address (not necessarily for publication). Newsy items will be welcomed.

With, headphones clamped to his cars each operator sits before a typewriter with a Morse keyboard at the side. This is a simple, unpretentious-looking instrument, but a depression of the key actuates a transmitter at Pennant Hills. While listening to a message from a ship, tho operator can, simultaneously, send a message to it, or to another vessel by tho Pennant Hills marine transmitter. Another operator is in touch with faraway Noumea. Others are exchanging traffic with ships, with New Guinea, or with tho coastal radio stations. Others again are listening-in to the latest Press news from England and tho Continent, or are receiving messages from experimental short-wave stations iu Europe- America, and the East. Day and night messages arc Hashed from all paits of the globe, to be [licked up by the ever-watching operators in Sydney. Tho touch of a keyboard, tho depression of a switch, immediately puts the transmission of messages into action. Altogether nine services are operated from the La Perousc station. Messages from Rukaul, the Fiji stations, and the beam station at Braybrook, Melbourne, received at La Pevomsc. are automatically relayed to Wireless House, York street. Tho eloctro-maguctic principles discovered by Oersted and Faraday a century ago, tho experiments of Joseph Henry, and the discoveries of Hurt great “electric king,” Lord Kelvin, the mathematical predictions of that brilliant physicist, James Clark Maxwell, and the laboratory work of Henrich Hertz in 1836, verifying Maxwell’s deductions, wore milestones in the evolution' of wireless telegraphy, even though many of these scientists were not, at tho time, aware of tho uses to which their discoveries were to he applied. Branley, Lodge, and Popolf, noted scientists, were also instrumental in advancing experimental wireless. it remained for Marconi, however, then a youth of twenty-one, in .189’). to devise a practical scheme of communication without the use of wires. A stroke of genius resulted in a new science which was destined to have a greater effect on human activities than any invention, except probably printing. of tho preceding nineteen centuries. Australia is in the forefront of wireless progress, and much of this is due to Hie experiments carried out by Mr Fisk during the last eighteen years, and his application of wireless to Australia’s needs. La. Perousc has become noted throughout the world for many noteworthy receptions. Of particular interest was the reception of the messages from the Southern Cross during the trans-Pacifu; flight. Li Perousc has also successfully received messages from Australian ships at Tilbury clock. Loudon, and from ships in the harbour at Vancouver, and at Sau Francisco, as well as maintaining communication for the whole of the voyage to and from Sydney. WO.MEN ANNOUNCERS. During November the British Broadcasting Corporation, after testing a number of women who applied lor posts as announcers, decided to adhere to the policy of using men only for full-time announcing belore the microphone.

The suggestion by the .8.8. C. tlnu women might be employed in the capacity of announcers led to a considerable number of applications from women, They were invited to Savoy Hill and given tests under broadcasting conditions. The capabilities of women applicants were carol ully considered. The 8.8. C. issued an official statement that there were no vacancies for announcers, male or female, and that it did not contemplate appointing women to full-time announcing posts in the near future. Among the women tested no suitable candidate was found. Six whole-time announcers are employed at the central station at Savoy Mill, and women arc employed before the microphone part-time, to announce programmes during the afternoon, in the children’s hour, and at provincial stations. That women have failed io pass the announcing test of the 8.8. C. does not come as a surprise, for it has always been recognised that while the voices of some women are very acceptable when heard in speech on the air. the conditions of announcing fall within a sphere peculiar to men. Announcing calls for a large degree of showmanship, and to got the best results out of a programme the announcer has at times to marshal considerable numbers who are to perform either in solo or concerted items during a session. Some event may end much sooner than was expected, a condition might arise which calls for a considerable alteration in the programme in an outside show, or the land line between the studio and the pieking-np point might go wrong, and it is then that the announcer has to estimate the capabilities of the forces at his disposal and see an impromptu programme through. LINKS Ob' FORCE. It seems queer to say that with phones over your oars and the cords imaging down, but not connected with the set. the programmes can _ be distinctly hoard at times. It will seem queerer, no doubt, that if you connect a plate of metal across tfie cord terminals the programme will be even mor > distinct, and can be always heard if the plate is anywhere near a nonsbiclded sol. Or for that matter, it the audio side of the set is shielded, simply connect or hold the ends of the phone cords against the shield. The whole secret of the matter can be visualised by imagining the field surrounding any wire or coil. Out Irom the wire or coil extend Faraday’s lines of force, like a magnetic field. Roth ends of the lines of force touch some ohjert. One end is at the wire or coil, and the other end may rest on an adjacent panel, desk, inkwell, phono cord, or what not. Suppose it rests on the phone cords or the pinto which short circuits tlmm, apparently. This is the electric field. Now imagine the field budding up and collausing at some audible frequency. The end of each line of force is an electric charge. As the field collapses these charges run off the plate. There is an actual movement of the electric charge, and, of course, a moving charge is an electric current. This electric current is what passes through the phones and gives yon the signal. It is worth noticing, too, that wherever there is an electric current there is a magnetic field accompanying the

j current. , So ns the charges move off | the plate there is a magnetic held around the plate. To go one step further, the collapse of this magnetic, field I " r iH create an extra current in the 1 plate also.