RADIO TOPICS.

New Zealand Herald, Volume LXII, Issue 19027, 26 May 1925, Page 13

RADIO TOPICS.

BY TIIEItMXON.

THE BROADCASTING COMPANY. Much concern is being expressed by listonors-in over tho failure to materialise of tho proposed Dominion Broadcasting Company, which was to re-organiso and control broadcasting throughout New Zealand. Tho listener-in was given to understand that, within u week or two of the appearanco of tho now Gpvornment regulations gazetted on March 5, the company would be in active being and ready to carry 011 an improved service. However, the promoters of tho company have taken exception to somo of tho clauses in the regulations and a deadlock has arisen. Mr. Esmond Greig, the secretary of the. New Zealand Broadcasting Syndicate, has forwarded to interested parties, including amateur radio organisatinos, a copy of a recent letter forwarded by him to the Postriiaster-General. This letter protests against tho delay in altering the parts of the regulations which tho syndicate has stated to bo unsatisfactory to it. Tho, specific points of disagreement aro not stated, and this is unfortunate as the list-ener-in is unable to decide to whom the present annoying delay may be attributed. Tho New Zeland Broadcasting Syndicate was formed originally at tho request of the Postmaster-General to formulate proposals for the n.uv regulations governing broadcasting and they did this without, be it said, obtaining any expression of opinion from tho organised lisfeners-in, who, however, were given an opportunity by tho Minister to discuss the draft of the regulations before they were gazetted. From tho viewpoint of the listener-in the regulations aro perfectly satisfactory. Neverllieiess, it must, bo remembered that any company taking over broadcasting in New Zealand will avoid any activities which are likely to result in ultimate financial loss. It has been stated that tho company promoters require a monopoly for ten years, whereas tho regulations provide only for a five-year tenure. A request for a 10-year monopoly is quit/: reasonable, since if' tho company is to provide a broadcast service acceptable to the listener-in and such as to induce tho public to become listencrs-iti—-an essential state pf affairs—then it must continue for some years at an inevitable financial loss. The company must be given a chance to recoup its losses. Any other points of disagreement, have not been made public. Public statements by the Minister and by the promoters of the proposed company 011 the apparent deadlock aro very desirable. The present state of affairs gives promise of adversely affecting the whole of tho future of broadcasting and is certainly antagonising the present licenseholders. * BROADCASTING BOARD. A circular at present being issued to license-holders by Mr. A. T. Markman, Secretary of the Post and Telegraph Department-, contains some interesting information concerning the proposed Broadcasting Board. It is stated that the board will consist of the Minister or his deputy; two representatives of tho Post and Telegraph Department, namely, the secretary and the chief telegraph engineer: one representative of the Broadcasting Company; one representative of the licensees of radioreceiving stations. The deliberations 'of this board are to embrace the technical, financial, operating and general administrative aspects ol broadcasting, as well as the most suitable lines of development. The fact that the Broadcasting Board will control the technical activities of the company is of interest and points to the necessity for the listeners' representative 011 the board to have had technical training in radio as well as being capable of battling for.the rights of the licenseholder. Nominations for this representative are to be in Wellington by June 21, and if a ballot, is necessary this will be held as early as possible. Only those holding licenses for receiving stations on May 31, 1925,' will be entitled to vote. HOWLING VALVES. About a year ago, the oscillating valve menace was so pronounced that an organised campaign throughout the Dominion was conducted by radio writers, the result being quite satisfactory. Unfortunately, however, there is a distinct recurrence of tho trouble in Auckland, and in some localities it is stated to be so bad that reception from the local broadcasting stations is being interfered with. When listening to a carrier wave, the operator of a receiving set knows that a shrill musical note is heard whose pitch rises as the set is mistimed either way until the note becomes inaudible. On closely tuning, the pitch of note heard is lowered until it is so low as to become inaudible, giving the silent or " dead" point while, 011 continuing to rotate, the tuning dial in the same direction, tho lowpitched note again becomes audible, continually rising in pitch with further rotation.' It is at the " dead" point that the music oi- speech is heard. The beginner usually understands that while he is tuned to this dead point where no carrier-wave is heard his set cannot be oscillating. In reality, if may be oscillating vigorously, and under these conditions may give rise to a particularly annoying interference in the form of ;r low growling note at a neighbouring receiver which is not oscillating. If the set is oscillating, the music, speech, spark signals or atmospherics will have a mushy quality to an extent that will offend any musical ear. If clear reception is desired oscillation of the receiving valve must be stopped. This oscillation is caused by pushing tho regenerative effect too far and there are very few types of sets which do not, when in the oscillating condition, act as transmitters having a range of a few miles. Having regard to tho types of receiving set used in Now Zealand it may be safely said that every oscillating valve • is a potential source of interference. Oscillation can bo kept umkr control in many ways, and those most useful in the ordinary set are by using a smaller tickler coil, cutting down the plato voltage and by reducing filament current. This latter necessitates a fine adjustment rheostat—an essential feature of any efficient receiving set. NOTES AND HINTS. A novel experiment is to be tried next Thursday evening when IYA will broadcast " Tilly of Tainaki." A recent report from Christ church statos that 3AG is to commence its transmissions on or about May 21, with an input power of between 300 and 400 watts. Batteries will bo used to supply tho power and clear transmissions ■ should result. It is said that neither money nor pains have been spared to make the set as nearly perfect us possible. Anyone who has listened to the harmonics of broadcasting stations must have been surprised at tho wastage of energy they cause. Tho first harmonic—on a wave-length half that of tho fundamental wave—is usually very pronounced, while succeeding harmonics should fall off rapidly in intensity. Listening to IYA Inst week the writer found the first harmonic on 165 metres to give signals of volume practically equal to those 011 tho fundamental wave of 330 metres. Listen-ing-in on tho second harmonic at 110 metres, the station could lie heard with excellent volume on the loud-speaker, using valve detector and two stages of audioamplification. Strong signals were also obtained 011 tho third harmonic at 82| metres. All the energy on the lower wavelengths is wasted and if means could be found of eliminating tho harmonics more energy and therefore more signal strength would be available on the fundamental wave.

lii building a iicnv set no particular phase of the work should ho rushed and makeshift parts should lie avoided. Go ahead carefully and build the set exactly as specified-, carefully chocking and rechecking your work, making sure of each stop as you proceed. This will ensure success. 1