WIRELESS NEWS

Press, Volume LXVIII, Issue 20624, 13 August 1932, Page 8

WIRELESS NEWS

(By "Max.")

Sir Charles Kingsford-Smith is evidently taking no chances of his radio equipment failing him during his projected flight across the Tasman next month. A complete sound-proof cabin will houso the apparatus, which will neigh something under two hundred pounds. This seems to be a heavy weight but perhaps the extra attachments for sound proofing are included. On the occasion of his first flight, a special simple code was employed for giving information relating to the progress of the aeroplane and points of interest during the trip. This would prevent piracy of the news, which was copyright.

Russia is not the only country where prisoners have devised wireloss layouts for inmate listeners, he it is .slated that a convict in the Sing Sing (U.S.A.) prison designed, manufactured, and installed equipment to allow all the buildings-at tlio prison to be fully provided with loud-speakers and headphones. There are over twenty of the former aiid nearly two and a halt thousand of the latter. The whole of the apparatus is fed by a. centrally situated receiver under the control of au officer of the famous prison.

Still another type of valve has been developed, but will not be available for the mnrkefc for a month or two. This valvo has no fewer than three platen or anodes. It is of tho indirectly heated variety, taking one amp. at 2J volts and tho maximum anode voltage is i?SO volts. The extra plates are used for the in-put, and this portion acts as a diode (two element t-übe, similar to tho first one invented by Fleming) and is to rectify the incoming signal which is then amplified by the other part of the valve. Uied in this manner the detecting and amplifying options are separated from one another. The pair of anodes on the in-put is connected across tho tuning coil and apparently tho rectified currents impress voltages upon the grid via a condenser. The grid \-oltage fluctuations tlicn actuate the ordinary anode current in the usual manner. The new valve is called the RCA-55, and has an amplification factor of just over H, and with a plate impedance of 7500 is somewhat similar to the 201 A tube. Tt will deliver an output of one-fifth of a watt.

Some set owners have probably removed the covers from tho tuning coils and have noticed that the winding i dvided into two portions, in that near the top end about a dozen turns, more or less, are not close to tho main number. The reason for this lies in the fact that copper wire, when being drawn through the steel die plates down to the required gauge, varies. With a new die the wire is tho minimum diameter, but this increases an the holes in the plate wear slightly. It is therefore necessary to allow for a length of coil winding, for a given number of turns, miflicient to allow for wire which is a fraction over tho correct diameter. The rule is then to drill starting nnd finishing holes at exact positions evenly spaced. Then if a thin wire happens to be used, some of the turns are pushed up to one end. Tho number shifted depends upon the result of a test against a standard coil kept for the purpose. If the inductance is too high, more turns are separated from the main lot until the test shows the correct tuning value. The closer the turns arc to each otlior, tho greater is the inductance for a given number of turns, and so the finer wire must be treated by separating some of the turns slightly, but still being kept within definite points.

It soems curious to note that low loss coils are definitely out of favour. In the older days when valves -were inefficient and also expensive, losses had to be kept down, but now that parts and tubes are cheap and power is cheap, too, due to power packs ousting batteries, then space is a big consideration and four-inch coils not desirable. Another point is that with successive stages sharply tuned, high note loss is present, and so coils wound with fine wire on small formers assist in proventing side band cutting. Condensers, on the other hand, have improved in •design, greater accuracy in construction being obtained and being very necessary. In any case the resistance of an ordinary tuning condenser to radio frequency currents is almost negligible. For the ultra high frequencies, down to and below 10 metres, some of the valve bases employed as coil formers are liable to be inefficient, as the composition from which they are made is occasionally not of the best, being moulded mud and including floorsweepings of insulation materials. The writer has seen one of these valve bases which would pass low values of direct current, and, cutting the base to pieces revealed a piece of brass wire imbedded »n the body. Reliable manufacturers eschqw such practices, and it is the cheap grade of socket which has to be suspected. The two best materials are Isolantite, a ceramia (porcelain), or bakehte and mica, but both have a disadvantage, the former not being machinoable and the latter requiring special tools for that purpose.

The Crosley Radio Corporation has obtained a permit to increase the power of their station, WLW, Cincinnati, from 50 kilowatts to 500 kilowatts. Initial experiments will bo conducted with not less than 100 kilowatts. It is hoped to obtain useful data upon fading and the extent of effective service area The trials will be held outside of the usual broadcast times. Other stations which have permission to operate with higher powers are WGY, with SOO kilowatts, and KDKA, with 400 k.w., though, duo to the economic conditions' neither has so far extended its outputs to any where near the limits allowed.

In the course of a month or so station WCAU, owned bv the Universal Broadcasting Company, and operated on 256.3 metres (1170 kcs.) will increase their power from ten to fifty k.w. A vertical aerial 500 feet in height will be erected and on the top an iron ball eighteen inches in diameter will increase the capacity to ground. Covering almost twenty acres, the station will have been put to an increased expenditure of £60,000. The earth system involves the use of ten miles of wire. To prevent danger to aeroplanes, special beacons and lighting will be required. There are 600 000 listeners in Canada and the Government intends increasing the annual fee from one to two dollars. The ouestion as to whether the Britis'' Broadcasting svstem should be used U under consideration by a parliamentary committee. « » At last week's meeting of the Radio Society, all th» officers who resigned v*r« r**leot*d, ih* ooly <ne*B4r tb»

Notes From Far and Near

3YA, CHBISTCHTJRCH (980 Kilocycles.)

3ZO CHEISTCHTJRCH. (1200 Kilocycles.j

2YA. WELLINGTON i 720 Kilocycles.)

BROADCASTING.

TO-DAY'S PROGRAMMES.

1180: Kesultß of Last Day's Races of Canterbury Jockey Club's Meeting at Riccarton. 3.0: Belay of Rugby League Football Match, England v. New Zealand (Second Test). 4.40: Sports results. 5.0: Children, by Aunt Pat and Uncle Charlie. 6.0: Dinner music. 7.0: News and reports. 7.45: Talk under the Auspices of the Town Planning Institute of New Zealand (Chnstchurco. Branch), Edwin F. Scotl, "Econora o Aspect." 8.0: Concert programme. Relay of programme from 4YA. Dunedin. 10.0: Sports summary. 10.10: Dance music.

o.iiO to 6.1* p.m.: Children's session. 6.15 to 6.45: Dinner music. 6.45 to 7.15: Sporting and general news. 7.15: Musical items. 7.45: Contract bridge talk. 8.0 to 10.0: Concert session. 10.0 to 11.0: Duuco programme.

ii.46. Relay. Rugby Football Match irom Athletic Park. 5.0: Children, by Aunt Molly and Uncle Jasper. 6.0: Dinn-r mui't. 7.0: News and reports. 7.30: W.E.A. Session, Professor T. A. Huuter, "Man aud His Social Institutions—Can Democracy Survive I" 8.0: Concert programme. Overture, 2YA Concert Orchestru (Conductor, Leon de Mauny), "Pique Dame" (Suppe). 8.10: Baritone, Ernest Short, "The Sun God" (James); "The Call of the Wild" (McGcogb). 8.10: Recordings (Humour), Joe Hayman, "Cohen on Telephone Deportment" '(Dayman). Michael Casey, "Casey at the Hospital" (Casey). H. 22: Soprano, Christina Orminon, "Hanks of Allan Water" (Auon.); "There's a Whisper in the Air" (Drahe). 8-28: The Orchestra, "Tho Areadiaiifs" (Mouckton). 8.40: Recording, Kotorua Mauri M:ilp Qunrtet. "iloo Mai e Iline" (A Maori Lullaby); "Mnringa Ai" (1 Urievo for You). «.4G: Will Bishop will entertain you at the piano. 0.0: Weather report and notices. 0.2: Reserved. 9.15: Suite for Strings, The Orchestra "Folk Tune and Fiddle Dance" (Fletcher). 9.23: Baritone, Krnest Short. "The Victor" (Sanderson); "Three for Jack" (Squire). 9.20: Recording (Male Quintet), The Singing Sophomores, "My Ohio Home"; "Chios" (Song of the Swamp) (both by Kahn). 9.35: Soprano (with orchestra), Christina Ormiston, "The Star" (Rogerß); "Ro«o, Softly Blooming" (Spohr). 9.41: Tho Orchestra, "Cuban Dance" (Cervante). •J. 46: Recording (Humour), Will Fvffe, "Dr. McGregor." Kyffe). 0.60: The Orchestra, »,!",.. <K»<--"ro»mnnff); "Albanian ; n Tr h t. ( ,"" n) - VKO: Sporting summary. 10.10: Ivelny of Dance music from Adelphi Cabaret. .

SUNDAY. ■■itA, CH&ISTCHUBCH. 2 p.m.: Gramophone recital. 5.30: Children a Song Service, by Church of Olirißt Sunday School. 0.15: Musical Chimes. 6.30: Kelay of Evening Service from Church of Christ. Preacher, Pastor Stuart Stevens. Organist, Mrs A. L. Pugli. Choir conductor, H. E. Ames. 8.0 (approx.): Concert programme. Selected recordings. 8.15: Christchurch Salon Orchestra (conductor, Francln E. Bate), "Highland Laddies" (Seredy). 8.27: Tenor, Hubert' Carter, Cycle of Gipsy Songs Hubert Carter, Cycle of Gipsy Songs (Dvorak), (op. 55): (a) "I Chant My Lay' ; (b) "Hark, How My Triangle"; (c) "Silent and l.one the Woods Around"; (d) "Songs My Mother Taught Me"; (e) "Tuna Thy Strings, O Gipsy"; (f) "In His Wide and Ample Vesture"; (g) "Cloudy Heights of Tatra." 8.43: Phyllis Kinniburgh, "Concert Study in F Minor" (Liszt). 8.47: Mezzo-soprano, Merle Miller, "To Music" (Schubert); "La Danza' ! (Rossini). 8.58: Salon Orchestra, "Popular Songs by Hermann Lnhr" (Lohr). 9.8: Weather forecast and notices. 0.5: Tenor, Hubert Carter, "Where the Wild Fowl Call" (Kahn); "In tho Silver Moonbeams" (Scott); "The Swan" (Lowry) ; "Love's Secret" (Granville Ilantock); "The Bold Unbiddable Child" (Stanford); "To One Who Passed Whistling Thro' the Night" (Oibbs); "The River" (Elgar). 9.20: Piano, Phyllis Kinniburgh, "Ballad* in O Minor" (Chopin). 9.26: Recording, Peter Dawson. "Thro' the Darkness" ('Rossini). 9.30: Salon Orchestra. "Far Across tho Desert Sands"; "Where the Abana Flows'." "Beloved, in Your Absence" (from Suite. "A Lover in Damascus") (Woodforde-Fin-den). 0.37: Mezzo-soprano. Merle Miller, "Yonder" (Oliver). 9.41: Recording (Organ), Edwin H. Lomaro, "Andantlno in I) Flat" (Lemare). 9.45: Recording. Russian State Ohoir, "Storm on the Volga" (Pastschenko). 9.53: Salon Orchestra, "How Many a Lonely Caravan"; "If in the Great Bazaars"; "Allah Be With Us" (from Suite, "A Lover in Damascus") (Woodforde-Finden).

SZO CHBIBTOHTJRCH. (1200 Kilocycle*.) 10.0 to 11.80 a.m.: Selected items. 6.15 to 8.0 p.m.: Dinner music. 8.0: to 0.50: Concert session. 2TA, WELUNGTON. 2 p.m.: Selected recordings. 6.0: Children's Song Service, conducted by Uncle George assisted by the Children's Choir from 61. John's Presbyterian Church. 7.0: Relay of Evening Service from the Taranaki Street Methodist Church. Preacher, Rev. T. R. Richards. Organist and choirmaster, 11. Temple White. 8.15 (appro*.): Concert programme. Relayed by 2ZD, Masterton. Relay of concert by Royal Naval Volunteer Reserve Band, from T* Luxe Theatre (conductor, Harry Baker).