Over The AERIAL

Waikato Times, Volume 111, Issue 18641, 20 May 1932, Page 10

Over The AERIAL

BY RHEOSTAT

THE COMING WEEK. Sunday. 1YA —7, service from Beresfoid Street Congregational Church; 8.30, Municipal Band concert at Town Hall. 2YA —7, service from St. Peter s Anglican 'Church; 8.15, concert by Royal Naval Volunteer Reserve Band. 3YA —6.30, service from St. Paul’s Presbyterian Church; 8, studio concert. Monday. IYA—Silent day. 2YA—Talks, 11.12 “Cooking,” 11.37 "Health Hints or First Aid,” 7.40 “Books Grave and Gay”; 8, studio concert; 10, dance music. 3YA —7.20, talk, “Work of the Empire Service League”; 7.30, W.E.A. session; 8, concert by Christchurch Citadel Band. Tuesday. IYA—S, programme of recordings; 9.2, talk, "The North-West Frontier of India.” 2YA —Talks, 11.12 “Fabrics and Fashions," 7.40 “For the Man on the Land”; 8, studio concert. 3YA —Silent day. Wednesday. 1YA—7.30, W.E.A. session; S, studio concert. 2YA —Talks, 11.37 “Hollywood Affairs”; 8, programme of recordings. 3YA —7.30, Addington stock market reports; 8, relay from Holy Trinity Church of Festival Anthem, “Fest Gesang”; 8.15, studio concert; 9.30, dance music. Thursday. IYA Matthew’s Church; 3.15, talk, “Home Science”; 7.30, W.E.A. session; 8, relay of Royal Auckland Choir concert at Town Hall. 2YA—Talks, 10.45, “Cooking,” 11.37 “Health Hints,” 3.15 “Home Science”; 7.30, W.E.A. session; 8, studio concert. 3YA —Talks, 3.15 “Home Science,” 7.20 “Farm Economies”; 8, programme of recordings. Friday. 1YA—7.30, sports talk; 8, studio concert. 2YA —Talks, 11.12 “Fashions,” 3.15 “A Talk to Post Guides,” 7.40 "The Law r s of Rugby Football”; 8, studio concert; 9.30, dance music. 3YA —7.30, W.E.A. session; 8, relay from Civic • Theatre of Christchurch Competitions prize-winners’ concert. Saturday. 1 YA—2.45, Rugby relay from Eden Park; 7.40, talk, ".Modern Ballroom Dancing”; 8, studio concert; 9.3, talk, “Wartime Spies”; 10, sports summary; 10.10, dance music. 2YA —3, Rugby relay from Athletic Park; 7.30, W.E.A. session; 8, studio concert; 10, sports summary; 10.10, ctance music. 3YA—B, Studio concert; 10, sports summary; 10.10, dance music.

ITEMS OF INTEREST. Overhaul Before Winter. The present is rather an appropriate time to remind readers that an overhaul of Itheir receiving sets is advisable before the winter arrives. Special attention should be paid to all halyards, new ones being rigged if the old ones show signs of weakness. Any soldered joints must be examined to ensure that there are no broken strands of wire in a stranded aerial. Have a look for any cobwebs across the lead-in, and otherwise carefully lest the connections to the lightning arrester, both on the set side and on the earth side. Reception is improving now, and everything which brings the aerial up to the highest pitch of efficiency helps to bring in the distant stations with more freedom from unwanted background. Will Depression Affect Renewals? License fees are once more due, and It will be interesting to see if the present conditions will affect renewals. The mere fact of having to take out the license fee for a full year may keep many from renewing for a period at any rate. It would be a step in the right direction if the Government, if only till conditions return to normal, would institute half-yearly or quarterly licenses and relievo the burden on a number of listeners. It would be possible to add an extra sixpence to quarterly licenses and a shilling to half-yearly ones to cover the extra clerical work which this system would impose on the department. Larger and Fowor Stations. Roland Barry, an Australian radio expert in London, is another advocate for larger and fewer stations, lie writes: —“The European ether is a paradiso for the owner of a wireless set. In the .'sst few 'months several super-stations have commenced operations—Prague with 120 k.w., Warsaw’ with i‘2o k.w., and the new Leipzig station. Many other European stations transmit with powers between GO and 100 k.w., and the main British stations are rated at 50 k.w." Obviously the day of “local" and low power stations has gone. 6CK and 2CO. The reason why 50K., Crystal Brook, S.A., conics across better than 2CO, Corowa (on I he Victorian-Wales border), is that it, has double the power. When SCK was opened it was described in Australian papers as a “sister" station to 2CO, both having a rating of 7500 watts. But 2CO has 7500 at the transmitter and 50K has 7500 in the aerial. This gives it three times as much volume as the largest of the Sydney stations. The Australian Wireless Weekly, referring to SGK, states that the new South Australian is heard in Sydney like a “local." The success of the station "proves beyOnd doubt thal fading, static, and the dozen other troubles which beset smaller stations are to a large extent overcome by the uso of powerful transmitters. The logical projection of the idea of high power in Australia is 2FU and ;tl,u on 50,000 walls." Activities Ovcrsoas. On the shores of the Adriatic it is intended to erect a super-power station for Albania with an output of 2 on kilowatts, \pparenlly an Amoricaii radio corporation has secured the

contract to erect and operate the station, which not only will give musical programmes but also will follow the American idea of advertising. It is stated that the new MoscowStalin broadcasting station, which uses .a wave-length of 424 metres, will employ an output of 300 kilowatts in 1933.. At present a modest 103 kilowatts is in use. From reliable sources it is announced that there are slightly over 1400 broadcast stations throughout the world, and of these almost half are in the United States of America. Seventy countries conduct broadcasts, and about 30 permit private enterprise to conduct wireless transmissions. Approximately 30 per 'jcent. of the countries make broadcasting a State monopoly, and a few allow a mixture of the two systems.

Daventry Short-Wave Station. The contract for the short-wave broadcasting station at Daventry has been placed with Standard Telephones and Cables Ltd., and work has already started. It is hoped to radiate initial programmes by the end of this year. The cost of the station will be about £50,000. This is £IO,OOO in excess of the figure estimated in 1930. Considerable use is made of directional aerials, or other reflectors, and it is interesting to note that the Empire is to be divided into five zones, each of which will be given special transmissions to ensure good reception between 6 p.m. and midnight, local times. This news relative to the building of the Empire station will come as a surprise to 4hose who are acquainted, with British radio, as it has been the general belief that the Marconi Company had a stranglehold on the transmitting matters in Britain. Value of Local Station. In commenting on the recent visit of the coverage commission to the district, the Timaru Herald says:—A good many listeners are inclined to believe that” a local station would solve a lot of their difficulties, but this is very much open to question. The main advantages claimed for a local station are that crystal sets could be operated, and that when static was had clearer reception could be obtained. Against this is the fact that there are already too many stations on the air, and that every additional transmitter would mean more heterodyning for somebody. Difficulty would be experienced when a local station was working in tuning in many outside stations. City set-owners have considerable trouble in getting overseas stations, and in this respect are not nearly so favourably situated as we are in Timaru. The cures for most of our troubles appear to be in more power and longer hours at 3YA and 4YA; abolition of silent days; arid suppression of mechincal interference. Increased power and fewer stations is the modern trend in broadcasting, anti is being adopted in England, America, Europe and Australia. New Zealand Trade. The receiver made in New Zealand is coming into more prominence every day, and some very pleasing sets have been put on the market by enterprising manufacturers. It is understood a receiver suitable for New Zealand requirements and manufactured in England is shortly coming on the market. English tube manufacturers are also making a bid for New Zealand trade, and British tubes to replace those of American manufacture are proving both reliable and popular. As the American base valve has becomo practically universal in New Zealand British manufacturers sending receivers to this country are adopting UX and UY" sockets as standard equipment, so that there should be no difficulty or confusion over valve replacements, a thing that in 'the past has been both annoying and expensive.

WIRELESS VALVES. INTERESTING APPLICATIONS. WIDELY DIVERGENT USES. Two papers arrived by the same post. One contained an account of the work being done in Holland on the sterilisation of food by means of highfrequency oscillations; the other a technical description of a pipelcss organ that has been developed in the United Stales. Two so widely divergent applications of what are commonly known as “wireless valves," are interesting indications of the many commercial and scientific uses, jii directions other than wireless, of Sir Ambrose Fleming’s discovery that a healed electric lamp filament gives off electrons (says Captain E. 11. Robinson in the London Observer). Wireless research has also made possible the newest method of ocean sounding by echo from (be sea bottom. The wireless waves that are being used for food preservation are very short, or ol' Ihe order of 25 ceniimetres, and arc generated by a valve oscillalor, which is simply a highfrequency transmitter. The discovery that these very short waves inhibit putrefaction in organic substances was made by accident about two years ago. The fact lias now’ been established definitely; but there is as yet no really satisfactory explanation. What is known is that a low-power oscillator establishes, after a definite period amounting to something over a week, an area around it in which the micro-organisms associated wil.ii. putrefactive changes cannot set up any chemical reactions. The com ■ mereial importance of Hie discovery is obvious. Its use depends on its cost and convenience as compared with present methods of food preservation.

The Plpeloss Organ. The pipeless organ makes use of a dozen or so electrically maintained tuning-forks and a large number of valve-amplifiers and lone-selectors which deliver their energy to about 15 moving-coil loud-speakers. The whole lone range and scale of an ordinary organ can be produced. The apparatus can bo built into a space considerably smaller than that required by a pipe organ wilh Iho same number of manuals and slops, and a very real advantage is that manuals and speaking apparatus may be widely separated from each other and from the sound generating portion of llie organ, wliieli may he housed in a cellar or in any oilier convenient place. The, “thermionic organ” may, or may nol, he able to compete with (lie ordinary type when builders’ estimates are required; but reports from musicians indicate that it is of real churchorgan quality, and the li-clmical description slates that the limbec of any known wind or siring instrument can be obtained, except that there is at present a difficulty in obtaining a true rendering of siring pizzicato. turning from thermionic \alve developments that may be of great import.nice in 1 lie fill tire, we have in the

Marconi Echometer a sounding apparatus which is on the market and which is being used. With the echo sounder measurements of vertical depth may be taken as many as -i0 times a minute in shallow water. The quickest land-lead sounding takes many minutes. A New Sounder.

Though the transmitter and receiver of Ihe Echometer is a quartz crystal oscillator, and though many wireless valves arc \ised in the apparatus, it is not a wireless instrument. The transmiller generates a sound above audible frequency and projects il downwards directionally. When ttic sound is rellccled from 1 lie bollom il is "heard" by the crystal oscillalor, and the time taken for the complete journey is translated into fathoms of depth on a scale, over which a spot of light travels. For the most accurate scientific work a correction for the temperature and saltness of the water would have to be applied, because these things affect I lie speed of the transmission; but for all ordinary soundings Hie instrument is sufficiently accurate without any correction. it is certainly more accurate than a hand or machine sounder.

Ollier applications of the thermionic valve !o non-wireless uses are many. There are Ihe valve-voltmeter, the telegraph and telephone line booster, the valve, relay, to name but a few. Ollier applications are being discovered rapidly, and it seems likely Unit the Lime Is not far distant when the wireless valve will play an even more important part in flic, convenience and comfort of civilisation than does Ihe electric lamp which gave it birth.