RADIO RECORD

Greymouth Evening Star, 17 August 1933, Page 3

RADIO RECORD

NOTES FOR LISTENERS-IN

(By

“Reception” )

£30,000 ACTION LONDON, July 1. The costs of a patent action whict is being heard by Mr. Justice Maug ham in the Chancery Division are es timated to exceed £30,000. Marconi’s Wireless Telegraph Com pany Ltd. claim damages from Philips Lamps Ltd., Charing-cross-road, for al leged infringement of a patent for im provements in wireless receiving sets It was stated that millions of sets embodying the invention have been sold. It was claimed to be based bn the discovery by Charles Samuel Franklin of the “no-man’s-land” between oscillation and no-oscillation, and of how this.region could be utilised to obtain greatly increased selectivity. After a hearing lasting twelve days, the evidence, in which over 4,000 questions were put and answered, was concluded yesterday. The trial will probably end to-day, when, it is expected, judgment will be reserved. Experiments have been described by experts, and the evidence has been so highly technical that the judge has had the assistance on the bench, of Professor E. V. Appleton, the wellknown wireless authority, as assessor. Philips Lamps Ltd. deny infringement, and challenge validity of the patent on the grounds of prior publication, common general knowledge, lack of subject-matter, and ambiguity. TAGS FOR LEADS Those little celluloid tags which yon buy for slipping on to battery and other leads are very useful and look most professional —but they have an annoying habit of getting lo.st when vou are building a new receiver. It is a most unwise proceeding to try to connect up a set without being sure of the correct leads at a glance and tying a varying number of knots in the battery cords—one for H.Tx, two for G.B. —, three for L.T. —, etc., —is not a satisfactory idea, despite its popularity! The simplest method is to beg, borrow or steal from the family mending basket a number of pieces of coloured wool which can bo tied round the leads and make identification a matter of seconds. ■ Another method is to buy a dozen or so of those little circular labels which are supplied in all colours by stationers for sticking at the bottom of important business correspondence. (They denote enclosures or something of the sort.) When stuck round the leads, these tugs make most handsome identification discs, and the appropriate lettering can be written on in ink. GENERAL NOTES Looking through some old radio magazines of not so many years ago, the writer was amazed at some of the prices secured for items of radio apparatus. There were horn loud speakers, priced up to £3O, and a pair of good headphones were a matter of several weeks’ pocket money. As to actual sets, the sky seemed to be the limit with price, 300, 400 and 500 dollars being just a good average. Do not be one of those misguided souls who completely box in their after bringing it home. If your radio is open at the back, then you may rest assured that it is deliberately built that way. If you close in the back, not only will it stop the ventilation of the set, but you will impair the lone, because it will boom and lose the natural effect. For aircraft radio, the aerial is carried in two ways. It is either slung on the machine itself or it is trailed behind with a fish tail weight at the end. In that case, the aerial

W X&F V* VW’ VS* is controlled by a hand reel, which hauls it in before landing. Power for radio on aeroplanes is obtained with i a small wind generator driven by a - tiny propeller. One of the best ways to connect a wire to any instrument in a radio is - to use lugs. However inexpensive ■i these’may be, there will come a time - when they arc needed and there arc . none on hand. Here is an easy method of making them from ordinary bus 5 bar. If an insulated wire needs a,, lug, i remove the insulation from the wire i ’about win. from the end and bend the 1 wire back over the remaining insula- . tion. Three turns of bus bar are then made around the bent wire and insula- ’ tion and the remainder turned off at . a right angle with a hooked t z urn at the end. It will be unnecessary to solder the connection of the Ims bar to the wire, as the bar can be wrapped very, very tightly. Every experimenter in radio seems to flatter himself that he will be the one man in the world who will never get a plate and filament mixed, but after burning out two or three tubes he uses precaution, and here it is at no cost: Get a piece of ebonite Ain x lAin; two binding posts, two pieces of spring brass Ain x lin; a Fahnstock clip and a piece of thin tin foil. Bore two holes that will take the binding post screws in the middle of the ebonite •»in from each end. Bend the spring metal so that it presses firmly on the ebonite after drilling a hole at each end the same size as those tiiat were drilled in the ebonite. These springs are placed on the binding posts so that they make firm contact with the posts. Attention is then given to the preparation of the tin foil strips. These should be cut about l-64in. x ijin. and several should be prepared and kept for future use. One of these strips of tin foil is placed on the ebonite and clamped down on the springs. The fuse is then ready for use and will save every experimenter a few good shillings. Do not keep your radio set where it can collect an enormous amount of dust. If dust gets into the works the efficiency of the outfit is impaired. Of course, this does not mean that the set must be guarded night and day, but an occasional blowing out around and about the condensers and coils is quite a good idea. For this job the writer uses a bicycle pump, and finds that it is quite efficient. Do not change round the valves in your set, for there are different valves for different purposes. On the modern type of set, of course, many of the valves have a different number of pins on the base, but you are only looking for trouble if you change valves round. Should you he troubled with annoying noises in your short wave battery set, look to the valve sockets. Provided that the batteries and valves and their components are in good condition, the valve sockets are often responsible foi’ clicking noises through the valves moving imperceptibly due to the vibration of the table. The simplest way is to make a band similar to a garter with a piece of elastic and strap it tightly around the valves. The writer has done this with an old short wave set that defied all efforts to locate the trouble, and the trouble has now disappeared. THIRTY YEARS’ PROGRESS. A HISTORY OF THE ART In “Wireless Over Thirty Years.” Mr. R. N. Vyvyan has successfully condensed into a single volume the story of wireless from its earliest beginnings to the present day, describing every phase of the development of practical communication. The author is an engineer who became associated with the Marchese Marconi in 1900. when

both were young men. remaining witl the Marconi Company to become on gineer-in-chief, and he has dealt vvitl his subject in ihe manner of an cn gineer, viz., thoroughly and concisely He has succeeded admirably in sup plying an attractive story free fron technicalities and bewildering terms In short, Dlr. Vyvyan's book is a worl in which both the layman and the en gineer will find the history of whal was, to many of the pioneers, a great adventure, set out in a manner whicl. is happy combination of interest and information. Commencing with the earliest forms of communication the author’ briefly describes the preliminary investigation of Faraday, Clerk-Maxwell. Hertz, Righi, Brandy, and Sir Oliver Lodge, in laving the foundation upon which Marconi built his structure, of practical wireless telegraphy. Then follows the storv of the conquering of the Atlantic, with its tale of triumphs and disasters, the efforts made to extend “range.” and the gradually increasing difficulties that had to be overcome, until finally the 'service was opened to the public. Mr. Vyvyan was personally associated with this work, and describes many of the incidents, amusing and otherwise, that occurred. The history of Imperial Wireless communication is set out with it's many conferences and long-drawn-out negotiations that unintentionally led to the establishment of a service which has far greater value than the original project could ever have bad. Although the first experiments had been on short wave lengths, long wave lengths had been adopted for all the commercial services, and every method of transmission had been tried, but in spite of every effort, it seemed that the art had reached a stage from which no further progress could be made, and that satisfactory world-wide communication was almost impossible. Suddenly the development of the valve as a generator of high power oscillations, the return to short-waves plus tne advantages of the “beam” system of concentrating the signal energy, cleared the way for the establishment of high-speed and reliable long-distance systems of communication. The manner in which the British Bost Office became seriously interested in wireless is interesting. Just before the war the Bost Office entered into contracts with the Marconi Company for the construction of a series of Imperial stations. These were cancelled on the outbreak of the war, whereupon the company made a successful claim for £OOO,OOO for damages. This was of immediate benefit to the company, hut Mr. Vyvyan points out the action was subsequentlylcostly, as the British Post Office became disinclined to let further contracts and turned its attention to development of its own services, with the result that, as is shown in a chapter devoted to the British Post Office’s contribution to wireless development, it has been responsible for many valuable technical advances and the establishment of he most powerful station in the world, viz., the Rugby long-wave station, as well as a complete system of telephony transmitters and receivers which have made England the centre of international telephony. The historic stations at Poldhu. Cape Bed, Glace Bay, Clifden, ahd Carriavon. as well as the modern equipment it Ongar, Brentwood, Croydon, Rugby, md Baldock and many other places, ire described along with an account if their working. All the modern applications of wireloss are mentioned, while the part that wireless has play?d in war on land, on sea, and in the iir, as well as its utility in peace time ’or marine rescue and communication purposes and its valuable application n aviation, have not been forgotten. TO-DAY’S PROGRAMME. IYA, AUCKLAND, 820 Kilocycles. 5.0: Children. 6.0: Dinner music. ’.O: News and reports. 7.30; W.E.A. Session: “Workers of New Zealand: How It Strikes a Carpenter.”’ 8.0: Chimes. Recording. 8.10: Choral, Auckland Commercial Travellers’ and Warehousemen’s Choir, “Ring Out, Wild Bells.” 8.LI: Recording. Piano, Hex. Brailowsky, “Valse d’Adicux.” >.23: Plantation Song, Mr. Robert L. Wilson. “Who’s dat a-Callihg.” The ilhoir, “Sweet and Low”; The Choir, ‘O. No. John.” 8.31: Recording. 8.39: rhe Choir, “The Soldier’s Farewell”; ‘London Town.” 8.46: Recordings.

JjUIiUUH JU»VII. O.JV. IHAAH-UUIfrO. 9.0: Weather forecast and notices. 9.2: Reserved. 9.20: Recording. 9.26: The Choir. “In Absence’’; “The Lee Shore.” 9.32: Recording. 9.44: The Choir, “The . Little Sandman.” Sea Shanty, The Choir, “What Shall wo do with the Drunken Sailor.” 9.51: Recordings. 10.0: Close down. 2YA. WELLINGTON, 720 Kilocycles 5.0: Children’s Hour. 6.0: Dinner music. 7.0: News and reports (2YC, 1010 kilocycles, after-dinner music). 7.30: AV.E.A. Session, Professor 11. H. Cornish. Professor of Law. Victoria University College. “The Law Process —The Counsel.” 8.0: March, 2YA Concert Orchestra, “Cadiz.” 8.5: Recording. 5.17: Instrumental, 2YA Concert Orchestra. “Selection of Songs.” 8.27: Musical sketch, Mr. and Mrs .[. AV. Bailey, “Good Luck—in Three Parts”: (i) “Horse Shoe”; (2) “White Heather”; (3) “Black Cat.” 8.37: Recording. 8.40: Lecturettc, Mr. B. R. Bliss, “The Life of George Borrow.” 9.0: Weather report and station notices. 9.2: Overture, 2YA Concert Orchestra, "Nell Gwynn.” 9.9: Sketch, Mi’, and Mrs J. AV. Bailey. “AVooing of Katharina by Petruchio.” 9.17: Suite, 2YA Concert Orchestra, “My Lady ' Dragon Fly.” 9.29: Recording. 9.35: Recording. 9.41: Sketch, Air; and Airs .1. AV. Bailey, “Salted Almonds.” 9.51: pizzicato Serenade. 2A’A Concert Or- , chestra, “Baby's Sweetheart”: valse, “Casino Tanze.” 10.2: Close down. 3YA. CH.CH., 980 Kilocycles. 5.0: Children’s hour. 6.0: Dinner music. 7.0: News and reports. 8.0: Chimes. Recordings. 9.0: AVeather forecast and notices. 9.2: Talk, Air. C. O. Barnett, “Borneo Impressions.” 10.0: Close down. 4YA, DUNEDIN, 650 Kilocycles. 5.0: Children. 6.0: Dinner music. 7.0: News and reports. 8.0: Relay from Concert Chamber of concert by Dunedin Returned Soldiers’ Choir. 10.0: Dance music. 11.0: Close down. EMPIRE STATION, Daventry. 5.15 a.m.: Time signal from Big Ben. From one generation to another ( gramophone records). 6.0: Time signal from Greenwich. Dance music (gramophone records). 7.0—7.15: : News bulletin. 11.0 a.m.—1.0 p.m. Transmission on an. omni-directional ; aerial. 11.0 a.m.: Orchestral concert. 1 12.15 —1.0 p.m.: Christopher Stone. \ Greenwich Aleaii Time.