Listen In!

Wanganui Chronicle, Volume 74, Issue 112, 14 May 1931, Page 10

Listen In!

NOTES AND PROGRAMMES

(By

“Detector.").

Mr Raymond White, of Wanganui, is giving a lecturette on music, from 2ZK, at 11.30 a.m. on Friday. A New Schedule A now schedule for 2YB, New Plymouth, has been arranged. This efficient and enthusiastically-run station will now be on the air on Mondays at 8.10 p.m., Wednesdays at 6.30, Saturdays at 2.50 and 6.30, and Sundays at 6 pan. Heating Up When an all-electric wireless receiver is installed for the first time, the listener may be surprised to find that it takes quite an appreciable time after the switch is put on before the valves function correctly. This is due to the period taken for tho heater elements to warm up. With some sets a howl maybe heard from the loud-speaker for 15 or 30 seconds and this gradually fades out as the set functions normally. Microphouic Valves Occasionally one comes across valves whicli arc excellent in every respect save that they are microphouic, and set up noises when affected by vibration. This fault is particularly aggravating in the case of a detector valve. A rough and-ready method of alleviating the trouble is to wrap the offending valve bulb in cotton-wool, or, in less malignant cases, to stretch one or two rubber bands around the bulb. Eliminator Noises If the use of a high-tension eliminator causes the set to work badly, and make noises like the engine of a motor-boat, a resistance of about 30,000 ohms should be inserted in each H.T. plus lead from the mains unit, and a condenser of not less than two mfds. should be connected from each H.T. plus tapping to H.T. minus. Polishing Ebonite Panels If an ebonite panel shows signs of discoloration, apply sparingly a little oil, well rub this in, and polish off with a soft cloth. This will bring back much of the original lustre. Radio’s Motto Tn all probability something like, a quarter of a million New Zealanders heard tho people’s verdict as expressed at the local election polls last week. How many of those who heard the announcements over the air, one wonders, gave thought to the medium, that brought to their ears so rapidly news of the pollings and compared its lightninglike service with the necessarily slow methods of pre-wireless days? With every occasion, such as last week’s elections, wireless is demonstrating its utility as an indispensable public service, whose motto, it may truly be said, is: “Service.” Wireless has not yet reached tho limit of its usefulness; it is only on. the threshold of greater wonders to come. Programmes on Short Waves An announcement has been made that in future 4ZO, Dunedin, will transmit on two frequencies, low and high. Programmes will be broadcast simultaneously on 49 metres and on long wave. The Next Best! Tho Broadcasting Company has de-, cided to put on tho air from-3 YA running descriptions of the Rugby League games played in Christchurch on Saturdays. This decision was followed upon a request for payment of £5OO to tho Canterbury Rugby Union for the right to broadcast matches under its control. The League officials have offered the right to broadcast accounts of their games gratis. It is stated that the public desires football broadcasts, and if the national game is to be banned from the air, then the next best substitute must be offered. Radio Exhibitions With the coming of the winter, which is termed the “radio season,” all the main centres are holding their annual radio exhibition. These exhibitions are usually conducted in co-operation with the Radio Broadcasting Company, who shift their studio equipment to the exhibition and give the night’s programme in full view of the public. In addition to tho novelty and interest of seeing how broadcasting is carried out, the public is able to see all the latest in receivers and compare them at first hand By this interest in radio matters is encouraged and the trade generally is benefited. A suggestion that is worthy of consideration is for Wanganui to hold a radio exhibition, possibly in conjunction with the winter show? Midget Receivers. There is a great vogue at present for so called “midget” receiving sets. Nobody who has tried building a set, even of the battery operated kind, can withhold admiration for the skill displayed in packing five, six or more valves, and their associated circuits into the space of a fair-sized clock and making them work, let alone adding in the same space a complete power-pack and a dynamic loud-speaker. These sets are almost miracles of construction and performance, and in general arc astonishingly cheap for the work they do. But merely because they are so small and so low in price, a word of warning is necessary. The manufacturer is compelled by the conditions of his undertaking to put as little material into the set as he can; both space and cost impose this condition. Now it. is a fundamental rule of electrical appliances involving power conversion, such as a power pack, which consists of a transformer, chokes, and condensers, that to reduce them in size below certain limits reduces their electrical efficiency, and this loss of efficiency is demonstrated by a single sympton—the generation of heat. This heat, which is of no use whatever for the purpose of radio re (•option, has to be paid for in the electricity bill, which may or may not. be a consideration for the user of the sol • it is of course no affair of Ihe manufacturer. It is, however, sufficiently grear, added to the heat given oil' by the valves, to make it quite risky to set a midget receiver with an open back close against a wall, or to enclose it in any way. It must have plenty of vcntilalion. A receiver which gets hot enough to smell of singeing should be regarded with grave suspicion and the dealer should be called upon.

POWER OF STATIONS Curiosity often arises over the meaning of the statement that a broadcasting station has such and such a power. What docs it mean? It certainly does not mean that the power named is tnc amount necessary to run th© transmitter—that power is always very much higher. Until fairly recently the “rating" of broadcast transmitters was largely a matter of taste or opinion—in some cases, on© fears, of sheer imagination. The ellcetivo power of a broadcasting station is, of course, the amount which is available for the actual work of broadcasting, regardless of the amount which has to be. used up to produce it. The International Union of Radiotelephony has given a definition which is now generally observed. A “transmitter is rated according to the unmodulated radio-frequency output when this is adjusted to the greatest value that can be fully modulated; it is the full load power input to the antenna, system when the microphone is idle. It •docs not follow that two stations of the same nominal rating •-m this basis have the same actual useful output; that will depend upon the degree of modulation. If the output valves are nearly full loaded when delivering the rated power, the available degree of modulation will bo small. : There will be a full-powered carrier, Wave and a weak musical output. If, however, the valves arc of ample power and the modulation is high—up to 100 per cent. —the musical output will be large. When the carrier is fully modulated the actual output is 1£ times the nominal rating. But this is possible only when the output valves are able without overloading to generate four times the rated power. This is because the instantaneous peak value of the power of a fully modulated carrier wave is four times its average unmodulated value. How much power has to be used in the station “in front" of the output valves to produce the required output is a matter of radio-engineering design. There are various arrangements, some more efficient than others. Modern transmitters of high efficiency have the following total power consumptions: For 1 kilowatt output, 11 k.w.; 2 k.w., 17 k.w.; 5 k.w., 32 k.w.; 10 k.w., 60 k.w.; 15 k.w., 90 k.w.; 50 k.w., 250 k.w. The average overall power efficiency of the station —output to input—from five kilowatts upwards, is thus about 16 per cent. Controlling Your Set. Nobody dreams of controlling a car by forcing down the accelerator home Lard and controlling the pace with the brake. Yet how many people tune a wireless set in with the wavelength dial alone? Regeneration is designed to make the set sensitive and as it is moved toward the oscillating point the set begins to breathe, as it were. At first scarcely perceptible, but gradually increasing until the set oscilates either with a plop or with a distinct hiss. Floppy oscillation is not wanted. It can be minimised by loosening a coupling between the aerial and secondary coils by varying the voltage and experimenting with the grid-leak. Do not go in with a bump, because, if you happen to be on a station, all your neighbours can hear it and, although it is just a bump with you, it is a roar, with them, because their set is amplifying the heterodyne note you make. If you turn your condenser right in to oscillation it is not easy to turn it back without causing undue noise. Keep it out of oscillation, just off the oscillating point. This is the point where the breathing is very strong, but not at maximum. If the oscillating point is past this it is not long before secondary oscillation, bringing with it a deafening roar, is encountered. When you come to think that an ordinary 201 A valve in a transmitting circuit can be heard at the other side of the world, you know just how far that noise is being transmitted. Do not do it. Keep the set under control. It is far better to have weak, clear signals than strong, distorted ones. When the set is just oscillating the signals are distorting. In other words, get quality and do not worry so much about the volume. Remember that when your set is in secondary oscillation you are using ten times the amount of current you would were it not oscillating. For practice, tune in the harmonic of th? local station and produce a clear and distinct signal. Aim for clarity, not for loudness. Listen on the 80 metres band to the amateurs. There are plenty | of them, and they make good practice in tuning, although some of them are very broad. Weather Reports. Townsfolk sometimes grow impatient when listening to the details of the weather report as broadcast by 2YA. but throughout New Zealand, especially in the country districts, the information thus given is greatly valued. An indication of its importance to shipping can be gained from the following extracts from a letter received by the Broadcasting Company from Captain L. Boulton, of the m.v. Maui Pomare:— “I desire to place on record by appreciation of the convenience and value of the weather forecast and reports which are broadcast from your station 2YA each evening. It will be readily understood that weather reports are of immense value to shipping, forecasting as they do the conditions which will be encountered by vessels in different positions and steering various courses." Captain Boulton adds that the ship’s wireless operator, Mr Hooker, rarely experiences any difficulty iu receiving the reports.

Analysis of Operations. An analysis of the broadcast service in New Zealand for the year ended March 31 shows that the four YA stations were on the air for the following times: IYA, 313 days, total hours 2395; 2YA, 324 days, total hours, 2392; 3YA, 319 days, total hours 2317; 4YA, 321 days, total hours 2263. The aggregate number of hours of broadcasting of all four stations was 9372. Dividing this time into the session classification, the limes work out: Afternoon sessions, 20.9 per cent; children’s sessions, 12.3 per cent.; dinner music, 11.4 per cent.; news and instruction, 10.3 per cent.; entertainment (main sessions), 33.4 per cent.; church relays, 3.3 per cent.; sporting relays, 6.8 per cent.; overseas broadcasts, .5 per cent. (43 hours); miscellaneous, 1.1 per cent. A Service Department. Make use of our Radio Repair Service. Radio is our speciality, therefor* l bring your repairs to the firm who specialise in this work. All and any classes of sets repaired. Valves may be the cause of poor reception, so bring them in, and we will test them free.— D. A. Morrison & Co., Avenue.* TO-DAY’S PROGRAMMES Following are the programmes of Australian and New 'Zealand stations scheduled for to-day. In :he case of Australian stations Austialian time is given in each instance, which is one and a-half hours behind that of New Zealand:—• 2ZK. WANGANUI. (595 Kilocycles). Programme of selected records from the stocks of D. A. Morrison & Co. Broadcasting hours 11 a.m. until 1.30 p.m. daily. It a.m. —Milan Symphony Orchestra. “Norma” Overture; Frank and James McCravy, "When You and I Were Young,” "Silver Threads Among The Gold.” A. and P. Gypsies—" Two Guitars,” "Shadow of the Past." Sandy McFarlane—"l'm Eighty in the Morn- ' ing,” "Bonnie Hielan’ Maggie.” Percy Grainger, piano—" Shepherd's Hey,” “Country Gardens.” Milt Shaw and his Detroiters—"To Whom it May Concern,” “When the Bloom on the Sage.” Bell solo —"Jollity One-Step,” “Happy Days” Schottische. Plaza Theatre Orchestra —"Three* Bears” Phantasy. Descriptive March—Chas. Penrose and Kaye Connor, “Laughing Policeman Up-to-Datc.” Ricardo Stracciari—Prologue “Pagliacci." Rudy Starita —Zylophone, "Lonesome Little Doll,” "Ragamuffin.” Brunswick Concert Orchestra—"Rosine,” "Feast of the Flowers. Denza Dance Band. "Baby’s Birthday Party,” Cupid on the Cake.’ P. C. Spouse. Mouth Organ—“ Medley of Irish Airs,” "Bluebells of Scotland.” Gaspar Cassado, ’cello—"Le Cygne” and "Melodic Arabe.” AL and Joe Blackburn, "In the Gloaming,” "Love’s Old Sweet Song.” Gerald Adams and the Variety Singers—“ Daisy Bell,’ "Break the News to Mother.” "Anglo-Persians—"Down South," "Call of the Desert.” All Star Californians—- " Three Little Words,” "I’m Proud of You.” Linn Mulford and his Hawaiians—" Honeymoon Waltz,” and “Kaiwaihau.” London Theatre Orchestra—" Maid of the Mountains ’ selection. 1.30: Close down. IYA, AUCKLAND. (>OO Kilocyc>e« : .233 Metres). 3 p.m.: Selected recordings. 3.15: Talk "Do You Agree With Your Food?" 5.0: Children’s session. 6.0: Dinner music session. 7.0: News session and market reports. 7.40: Talk— “Citrus Fruit Products, namely. Peel, etc.” 8.0: Relay of programme by the Bohemian Orchestra, under the conductorship of Mr Colin Mustin, from the Auckland Town Hall. 10.0 j God Save the King. 2YA. WELLINGTON. (720 Kilocycles.) 3 p.m.: Chimes. Selected gramophone recordings. 3.15: Lecturette—Miss I. F. Meadows, "Do You Agree With Your Food ?” 3.30 and 4.30: Sporting results to hand. 5.0: Children’s session, conducted by "Uncle George” and ‘Big Brother Jack.’ 6.0: Dinner music session. 7.0: News and market reports, and sports results. 7.40: Lecturette—Miss Inez Connop, “American Ballroom Dancing.” 8.0: Chimes. Studio concert by the Wellington Artillery Band, and 2YA artists. March —Band, "The Assemblyman” ; fantasia, “Scottish Memories.” 8.13: Baritone—Mr Ken Rigby, (a) "Mate o’ Mine,” I b)'“Your Eyes Have Told Me So.” 8.19: Choral—The Philomel Choir, "Ave Maria.” Contralto—Miss Rae Burns, "Husheen.” Duet—Misses Hitchings and McDavitt. ‘The Coulin.” 8.27: Indian intermezzo—Band, “Aisha.” Cornet solo — Sergt. W. H. Bowman and Band, “Annie Laurie.’” 8.39: Vocal quartette Misses Hitchings, McDavitt, Burns and Burge, "Rose in the Bud.” Contralto—Miss Roma Burge. "The Woman and the Horse.” 8.4: Accordeon duo—Gellin and Borgstrom, (a) “Darby and Joan,” waltz; lb) "Rio Negro” Tango. 8.50: Selection —Band. “Rigoletto.” 9.0: Weather report and station notices. 9.2: Super Cinema Orchestra. "Love’s Dream After the Ball." 9.6: Choral—The Choir. "A Bowl of Roses." Contralto—Miss Zoe Millar. “Come to Me. O Ye Children.” 11.12: Waltz—Band, "Aileen Allanah.” 9.19: Baritone—Mr Ken Rigby, "Heart of a Rose.” 9.23: Xylophone—Franz Kruger, "The Spanish Beggar Girl.” 9.29: Vocal quartette—The Philomel Quartette, "The Two Clocks.” Duet—Misses Syme and Burge, "None So Pretty.” Mezzo-sonrano Miss O’Regan, “When the House is Asleep.” 9.38: Humoresque—Band, “Who’s Dat a’Callin”.”” 9.44: Quartette—The Philomel Quartette. “You Stole My Love.” Choral—The Philomel, “In an Ancient Hostelry.” 9.50; Balalaika Orchestra, Gorskaja, (a) “The Red Sarafan,” (b) “Immer Lustig.” 9.57: Band, “Rocklea.” 10.1: God Save the King. 3YA. CHRISTCHURCH. (980 Kilocycles.l 3.0: Gramophone recital. 3.15: Lecturette —“Do You Agree With Your Food?” 3.30: Gramophone recital (continued). 4.25: Sports results. 5.0: Children’s session. 6.0: Dinner music session. 7.0: News session. 7.30: Talk by Dr. F. W. Hilgendorf, Lincoln College, “Sowing the Wheat.” 8.0: Chimes. Overture—Marek Weber’s Orchestra, “Cavalleria Rusticana” selection. 8.8: Baritone — Mr K. M. Fountain, (a) “Trees,” (b) “O Lovely Night.” 8.14: Piano—Miss L. Merle Miller, “Pastorale and Capriccio.” 8.19: Flute—Mr W. Hay. (a) “ ’Tis But a FewSweet Flowers.” (b) Rondo a la Tarantella.” 8.25: Mozzo-contralto—Mrs Sen Jowett, (a) “Nonso Piu,” (b) “The Linden Tree.” 8.32: Violin—Miss Irene Morris, “Scherzo.” 8.33: Instrumental—Studio Trio, “Trio in G.” 8.49: Baritone—Mr K. M. Fountain, (a) "All That I Ask,” (b) “The Roman Road.” 8.53: Flute —Mr W. Hay. "Idyll.” 8.58: Piano—Miss L. Merle Miller, “Consolation No. 3.” 9.2: Weather forecast and station notices. 9.4: Lecture by Te Ari Pitama, “My People.” 9.19: Mezzo-contralto—Mrs Sen Jowett. (a) "The Spring’s Blue Eyes,” (b) "Slumber Song.” 9.23: Instrumental—Studio Trio, (a) "Prelude”: (h) “Minuetto.” 9.30: The RailevMarston Dance Orchestra will aupply dance music until 11 p.m. 11.0: God Save the King. 4YA, DUNEDIN. (650 Kilocycles.) Silent day. 4QG, BRISBANE. (393 Metres; 760 Kilocycles.) 7.0: Market report and News Service. 8.0: Programme from the Studio. 10.'): Weather information. JO. 10: Dance music till 11 p.m. 2FC, SYDNEY. (451 Metres). 5.45 p.m.: Children’s session. 6.45; The A.8.C.. Orchestra. 7.20: A.B.C. sporting and news items 8.0: Studio concert programme. 2 BL, SYDNEY. (353 Metres.) 6.15 p.m.: Dance music. 7.5: Country session. 7.20: Dance music. 8.0: Studio concert programme.