WIRELESS NEWS

Press, Volume LXIII, Issue 19156, 12 November 1927, Page 10

WIRELESS NEWS

(By Listener.)

Around New York City there are eighty broadcasting stations. Chicago is surrounded by sixty-eight, Boston thirty-two, and Kansas 10. If signals from a receiver vary unaccountably in strength, make a careful examination of the friction contact. The valve logs, for example, may have become dirty, and slots in the plugs of coils may require opening with a penknife to'ensure close fitting in the socket?. Dull-emitter valves with thoriuted filaments, which appear to have lost their power of emission, may be restored by lighting the filaments at normal brilliancy for a few hours with the high-tension battery disconnected. Coated filaments will not yield to this treatment. Use a high-resistance voltmeter to test H.T. batteries, and measure the potential whilst the set is in operation —preferably after it has been working for about half an hour. Dry cells, and. indeed, accumulators, have a habit of '''pinking up" when off load, and thus a false reading may unwittingly be taken. * * Do not tost your high-tension dry cells with an ordinary moving-iron voltmeter. The amount of current consumed by such an instrument is, in most cases, greatly in excess of that used by the set. Apart from the likelihood of false voltage readings, the life of the unit may be shortened by employing this kind of voltmeter. * * When inserting a screw in an awkward position among the works of a wireless set, great help will be obtained by using an "artificial finger," made by forming a loop at the end of a length of wire. One strand taken from a piece of 7-22 gauge aerial wire is admirable for the purpose. The threaded part of the screw should be placed through the loop, enabling it to be held in position while the driver is used. When the screw is in position the wire can easily be pulled away. The matching of a set and loud speaker is very important. The instrument must be selected with care, as it is the means of transforming the electrical vibrations of voice and sound into sound vibrations that are audible to the human ear. It is useless to connect a cheap loud speaker to a set having a very good amplifying system. On the other hand, if a set has a poor amplifying system and it is connected to an excellent loud speaker, the quality will be no better than that delivered to the speaker IMPORTED SETS. THE POSITION REVIEWED. Probably no country has a greater variety of receivers that we have in New Zealand: variety, that is, in the sources of supply. In addition to many excellent New Zealand-made sots there is a wide choice available of imported sets and components. It looks as if the American imports exceed those of all other countries, both in complete sets and component parts —Europe has been about eighteen to twenty-four months behind America in the development and production of wireless receivers until recently. Now there are signs of -Europe catching up in progress. Not all of the European countries show that progressive tendency, of course. The countries where radio seems to have won the public popularity most widely are Great Britain, Germany, and Russia. Strangely enough France is not as well to the fore as might be expected. Some may deplore the fact that so much radio material is imported. They would like to see manufactures grow in New Zealand to such an extent that foreign sets would be unnecessary. However admirable a policy it is to encourage a new secondary industry—and of course it is admirable and desirable—the of broadcasting should not suffer thereby. It is stated by some proponents of that policy that a practically prohibitive tariff should be placed on foreign sets, so as to allow the local industry to be developed. That policy might bo carried too far: The general public may not have the I facilities now available of making. a selection from a wide range of designs from different countries. It is desirable to allow listeners and home constructors to keep up with the advance of radio in countries where millions of pounds can be spent on research and development. That could be done, and at the same reasonable facilities be given to New Zealand manufacturers. England started off in 1922 by blocking the importation of sets for two years, and it is doubtful if the policy was a wise one for the public generally. Since that barrier was removed, the British manufacturers found that they could give more attention to the manufacture of sets for export as well as for local use, but the British export trade in radio is being challenged severely by Germany; it always was, of course, by America. The export figures for 1925 and 1926 how a steady advance by Germany and a decline both by England and America, and America exported £2,042,000 worth of radio goods in 1925, while in 1926 it decreased to £1,813,000. Great Britain's figures for the same vears were £1.250.000 in 1925 and £1.266,000 in 1926. Germany on the other hand showed an increase as follows: —1925 exports amounted to £1,478.000. while in 1926 the figures were £1.581,000. It looks as if Germany is making a determined hid for the export trade. There are not many German sets so far in evidence being used in New Zealand, but apparently the sets are being manufactured in ouantity and sent to other countries. We can safely rely on New Zealand tracers, however, to see to it that German sets, if they do come in, are of efficient design and economical prices. An "electric cow*' is used to provide passengers of ocean liners with milk. The machine produces milk from milk powder, unsalted butter and water. An opportunity was recently given a "Press man to learn the number of "listeners-in" using crystal sets and J.I.S. 2 stage amplifiers and so get loud-speaker strength. This information proved that the large majority of Amplifiers in use have been supplied by J. I. Smail,. pioneer radio firm. —6

Notes From Far and Near.

ELECTRICAL OPERATION. NEW ERA IN RADIO. .Refinements in electrically operated receivers, compactness of design, and general adoption of the single-tuning control were the outstanding develop ments revealed by an analysis of the new radio styles displayed at the recent Radio "World's Fair in New York. Fittingly, it has been said that radio engineers, interior decorators, and artists have worked hand in hand in developing the 1927-28 receiving sets. Last year many people hesitated to buy light-socket sets because of the contention that this typo of instrument was in the experimental stage, says a writer in the New York "Times," but now about 30 per cent, of the new sets are electrified and. the other 70 per cent, are designed to operate with batteries. The manufacturers say that those desirous of purchasing batteryless receivers need not fear that the 1927-28 circuits are in the experimental stage or that this type of set will require too frequent servicing. They contend that the development of new alternating current tubes and improvements mado in rectifier tubes have made practical the building of. dependable light-socket sets. It is pointed out that not only tho mechanical and electrical refinements in apparatus have aided builders in producing high-quality instruments, but the fact that licenses have been granted to many independent manufacturers, making, available basic patents, has enabled them to construct superior receivers. However, it would be well for radio purchasers to bo guided by the advice of a merchandiser's oracle which recently sounded a warning to dealers advising that they should proceed with the utmost caution in stocking alternating current receivers. "Consider the system employed, the construction of the unit, and the integrity of the manufacturer," is the suggestion. This is excellent advice to follow, not only for dealers, but for the public buying any type of radio' set, whether it be electrically or battery operated. It is expected that next year the percentage of electrical sets will be greater. However, there is no doubt that there will be a large demand for battery-operated receivers for many years _ to come, because the electric facilities are not available in every home. The great advantage of the light-socket set is in the fact that its power supply is available by the snap of a house lighting switch. Furthermore, there are no batteries to charge? or replace, and the power supply is constant. The advantages pointed out for the batteries are"pure direct current, steady, quiet, noiseless, uniform operation, taking nothing from -.ml adding nothing to radio reception—no line troubles or blown-out fuses can stop reception—you need never miss a single concert from a bat-tery-run receiver." There is a large assortment of "A" and "8" eliminators which enable sets • designed for battery-operated tubes to take their power supply from the light-socket. The popularity and dependability of these units are revealed in the fact that one manufacturer has 2,000,000 eliminators in actual use. To go a step further, the combination power amplifier "B" eliminator has | been .developed. These devices plug- | into the receiving circuit after the I first audio amplifier tube. They supply the "B" voltage for the set, and act as a power amplifier which gives excellent tonal quality, and intensity that can bo regulated from a whisper to volume sufficient to fill a large auditorium. The last audio tube in the set, which is generally of the power type, is not required when- this instrument is employed. The metal chassis and shielding of circuits in individual compartments have been adopted on a general scale. The drum-control method of tuning is more popular than ever because it affords the single adjustment which simplifies tuning. The wave-length readings appear through a tiny window or slit in the panel. Tho old style of external dial is rapidly vanishing, and within a year or two it is likely to be an antique, along with the long gooseneck horn, which was popular in the early days of broadcasting. The old horn has surrendered its popularity to tho dfsn or cone loud-speaker, except in cases where a long air chamber or r'exponential" type of horn is used that is entirely different from the old typo of horn. The long air chamber horns, some of which measure as much as seven feet, give exceptional tonal quality, as do the latest cone designs. ~ It was said last year that radio apparatus had been "simplified, standardised, and made foolproof." Refinements in instruments have enabled lurther simplification in construction and manipulation of the circuits; cooperation between the manufacturers and availability of patents have aided m further standardisation; more sturdy construction and the lessons learned from having equipment in use for another year have helped engineers to see how they can build the sets more foolproof. Thus, the 1927-28 models ara not likely to need the frequent attention of a service man. A PARTY AT REDCLIFFS. MAGIC IN THE BOTTLE. Some friends were out the other evening at a party at Redcliffs. One of the ladies had brought her young child aged four with her, and the youngster was asleep upstairs. Quite suddenly he started to cough, and he appeared to be going to keep it up all the evening. The worried mother said, "You know, Gerald has just had a cold, and I cannot get rid of that cough," "I'll soon fix that," said the hostess. "Do you mind if I give him some of my favourite remedy?'? The mother gladly consented. Gerald was promptly given a dose of Baxter's Lung Preserver, the coughing quickly subsided, and the party went on uninterrupted. "My word, I must get a bottle of that," said the grateful mother. "I have often heard about 'Baxter's,' but I have never tried it." There are very few people in New Zealand who do not pin their faith to Baxter's Lung Preserver as a sovereign remedy for coughs, colds, and bronchial complaints. It is a rich red, warming, soothing compound that does you good from the first dose. Good for children and adults alike. Besides being a splendid cough and cold specific, 'Baxter's' possesses wonderful tonic properties that help to build you up. Y'ou can obtain a generous-sized bottle of "Baxter's" from any chemist or store for 2s 6d; bachelor size Is 6d. —lO