RADIO AND ITS RECEIVERS

Sun (Auckland), Volume I, Issue 215, 30 November 1927, Page 16

RADIO AND ITS RECEIVERS

Conducted for THE SUN by 1 Transmissions from the Auckland station surely reached their lowest ebb last Wednesday, and with much more of this sort of thing we will be well back in the dark ages of complaint and universal dissatisfaction. Why are we getting such programmes? The relay of the Takapuna races was most successful, and Mr. Stringer is deserving of success in persuading the other racing clubs to permit the broadcasting of their meetings, as radio is the greatest publicity medium of the age. In connection with this relay an excellent example of how a Government department can serve the public was given. The lines to the station from the course were at first very noisy, and the departmental officials worked tirelessly and gave at the last minute a perfect line —a piece of work which should breed confidence in the efforts of the Post and Telegraph Department to see tliat listeners get as good as is possible to be got. Another pleasing relay was the broadcasting of the Auckland wool sale. Such novelties as this will do much for radio, particularly in its slack season. PROPOSED ANGLICAN STATION This proposed station has had its licence allotted to it and the wave length allotted shows excellent choice—in fact, one would not be far out in saying that this station has easily the pick of the bunch. The technical side is largely in the hande of the Rev. Mr. Smyth, of Onehunga, who is and has been one of our best-informed scientists right from the days when he was a contemporary at Canterbury College with Sir Ernest Rutherford. Many have jumped immediately to the conclusion that this station is necessarily for Auckland, but the situation of the station, the writer believes, will be determined by the region which will be best served from the point of view of crystal owners, and also from the point of view of the region which shows the greatest support toward the financial side of the venture. The plan is to get subscribers who will pay a yearly donation toward the station, so that the old joke about switching off the set when the collection is being taken up has lost its point. BROADCASTING PATENTS On November 18 a very interesting message was received from Australia dealing with the finding of the recent Radio Commission. The message was as follows: "The Prime Minister, the Hon. S. M. Bruce, introduced in the Rouse of Representatives a Bill to amend the agreement between the Commonwealth Government and Amalgamated Wireless of Australasia, Ltd. "The Bill provides for free patent rights to oroadcasters, listeners and dealers, in consideration lor whicn the company is paid. 3d a month a listener (instead oi od as formerly) by the Government The company is allowed to retain the present stations owned by it and the agreement is of five years' tenure. Official news bulletins from England are to be received by newspapers and broadcasters without payment of a special royalty. “The company has to carry on with already instituted actions against the violation of its patent rights. The most important part is that the company is to commence corresponding actions in New Zealand." These actions if successful in New Zealand are going to make all our radio a more expensive luxury and will limit still further the progress of radio here, for if the Radio Broadcasting Co. of New Zealand has to pay out a sum to Amalgamated Wireless, that sum must come from either the company’s profits or from the money provided for programmes, and with 40,000 listeners, this royalty would amount to £6,000 a year, a formidable sum as things are in New Zealand, where the Broadcasting Company is faced with the problem of the cost of four stations to supply a smaller number of listeners than most of the Australian stations supply. The radio royalties are holding the attention of dealers and listeners all over the world. A reflection of the American aspect is seen in some of the new models which have a restricted balancing control. The range of this allows of small variation to suit samples of the 201 A type of valve, but does not allow sufficient control to enable valves of other countries to be used. In Great Britain the Marconi royalties were the subject of vigorous expression at trade meetings held during the Olympia Show week. Since the very early days of the industry the substantial royalty fees have held it back, and to-day, with the considerably reduced prices, the payment of these fees has become much more burdensome. On the cheaper types of sets sales are substantially reduced, as this royalty amounts to 12s 6d a valve irrespective of the type of set, and also applies to the valve eliminator and charges a like sum. The Marconi Company refuses to recon-

M. Taylor, B.Sc., M.I.R.E. siaer this amount of 12s 6d a valve, and announced a small concession on exported goods: but the British dealers demand a r cutniode British dealers demand a reduction of the 12s tid. We in New Zealand have been quite free from such troubles with patents, but it looks now as though cur Government will have to defend its attitude. A review of the European situation showed that no royalties were paid in Holland, Portugal, Spain or Italy; in France the position was very involved, but the majority avoided payment. In Germany 2s 6d was paid for a onevalve set and in the case of multivalve sets Is 6d was paid on the first valve and 6d a valve after that. In the case of export to Australia, the British imports were the only ones which paid a royalty; American sets paid nothing at all. Again, the arrangement with the Marconi Company was that sets exported from Great Britain to Australia paid in England a royalty of 2s 6d and the Amalgamated Wireless Company should collect a further 12s 6d. but as this company was unable to make its collection, the British manufacturer was called on to pay the whole 15s, an obviously unfair state of affairs. NEW SOUTH WALES STATE SERVICE The plans for the New South Wales State broadcasting, according to a Sydney paper, have been extended and will probably cost £30,000 instead of the original sum of £23,000. In addition to the Sydney station and six relay stations, there will probably be 30 subsidiary stations of low power. AMONG THE NOVELTIES Among many novelties shown at Olympia were a small grid-leak drippan designed to take the drip from an overworked leak, and it is said to have been quite a popular investment, the joke not occurring to many. Another new device was a tuning control, which gave a small illuminated picture on the panel of the town, and station tuned in. LEAD-IN SYSTEM The lead-in system is a point of weakness in most aerials. The conditions necessary for the best results are perfect insulation, effective spacing from adjacent walls and freedom from twisting or swaying. In connection with the first essential the lead-in tube should be of some good insulating material, and pointed downwards so that any moisture will run off instead of running back toward the set. An alternative is a weight on the iead-in wire, which gives the wire an upward slope to the tube, giving much the same effect as the sloping tube. This weight if used in conjunction with a stand-off spar, terminating in a ring insulator through which the aerial wire runs, will keep the wire taut and prevent swaying, and so answer both the other provisions for a good system. An alternative is a stiff spring of flat brass bent into a U shape, to which the wire is soldered and the free end of the U is then fastened to the lead in tube, the bottom of the U being toward the ground. While on the subject of aerials, one rarely sees a neat lead from the aerial proper to the set. Often as not a great clumsy joint is made, or the aerial is given a series of twists, which, while being strong, are not a really workmanlike job. One of the best jobs seen was done by fastening the insulator to a piece of stranded wire, leaving two ends about 10 inches long. The aerial and lead-in were kept as an unbroken wire to the lead-in tube, and, at the point decided on as the termination of the aerial proper the wire was bent into the shape of a quadrant of a circle, along each of the straight arms one piece of the two wires attached to the insulatbr was carefully braided, leaving the arc between the two joins. The insulator was then attached to the rope, and when hoisted up gave a very neat appearance, the aerial curving down into the lead-in wire in a free curve.

USING GRAMOPHONE ADAPTERS This instrument, which is really a loud speaker without the horn, does not seem to have enjoyed the popularity that it deserves. The gramophone makers have paid great attention to the acoustic properties of various types of horns and sound boxes, and the tone of the modern machine is full testimony of their success in this respect. This unit is applied to the tone arm, and uses the gramophone horn as the loud speaker horn. The results are superior, given a erood unit and a good gramophone, to most loud speakers on the market. The writer had the opportunity of hearing two such units in the home of an Auckland music lover, who will not go back to his expensive speaker on any account, and the results fully justified his decision. The full, rich tone, with a much more even amplification on all notes, was noticeable. Blasting was absent and the units used were capable of standing a very large amount of volume without distortion. The two units used were a Cerman one, the Nora, and a British one, the Brown, both of which can be recommended to those who wish for something really good in the way of reproduction. We have now the two states, the gramophone used to reproduce wireless and the electrical pick-up, with audio amplifier, and loud speaker. Why not an electrical pick-up, an audio amplifier with loud speaker unit attached to the gramophone horn? Surely this has possibilities. A RADIO HOWLER Radio cannot really be as universally known in England as one would suppose, if the following schoolboy howler is any criterion; “What is the 8.8. C. and where are its headquarters?” a Bradford schoolboy was asked in a general knowledge test some time ago. The reply was "Bradford Bowling Club Park Avenue."—Leeds “Mercury." REDUCING HUM IN ELIMINATOR That a hum is audible in many otherwise very satisfactory eliminators must be admitted, and as one purchaser told, the writer, he was quite satisfied with the article—in fact, it was a "humming success.” This hum is usually not heard while signals are tuned in, but can be heard during any interval. Four causes of hum can be dealt with and removed quite easily: (1) An electro-magnetic coupling between receiver, transformers or filters and the power-transformer in the eliminator. This applies particularly to the first stage L.F. transformer. This may be removed by moving the eliminator further from the receiver or can often be got over by a readjustment of position, a move of a few inches, or turning through a small angle will often get over this trouble. (2) Where an automatic relay is used, electro-magnetic coupling between the power-transformer and the magnetwinding of the relay may cause a hum which can be got over by moving the relay to a new position. (3) WTiere the high voltage tap is ised, the hum can sometimes be got id of by taking the high-voltage tap rom some different point in the filter .‘ircuit, as less filtering is needed on the plate of the power-valve.

) (4) An incorrect value of the C bat- ! tery bias may cause a hum, and here j the simplest way is to exper nt and find if a change of C battery volti age makes any difference.