WIRELESS WORLD.

Taranaki Daily News, 31 May 1924, Page 13

WIRELESS WORLD.

CONDITIONS CONTINUE BAD. STATIONS HEARD THIS WEEK. ((By "Honeycomb.”) The conditions existing during the last few days have not been favourable for good reception. Static has been very bad on several nights, arid although stations could be, heard they did not seem to have their customary volume. On Sunday evening last 4YA (Dunedin) came in fairly well, there being sufficient volume to operate the loud speaker. His programme was most appropriate for a Sunday evening, consisting of hymns. Amateur C.W. stations logged were 2CR (N.S.W.) and 2AO (Mr. Brunette, Opunake). Signals from both these stations were Q.S.A. On Wednesday broadcast was received from KGO (Oakland, California). At times the music and speech was very clear and distinct, but static was very fierce on this particular night, and as a result of this most of KGO’s announcements were missed.

Mr. E. W. Bierre, the young Wellington radio inventor, has been experimenting lately with a home-made receiving get, using radio frequency, with which he has picked up music from 2BL, Sydney, using as an aerial a spring mattress. MUSIC FROM AMERICA. Mr. F. J. O’Neill, proprietor of station '4YA, Dunedin, reports picking up broadcasted orchestral items from some American station at 11 a.m. on a recent Sunday, the programme lasting well into the afternoon. This is a creditable performance, especially so when it was achieved in broad daylight. Mr. O’Neill says that the announcer did not proclaim the identity of the station, but it is believed to have been Chicago. Mr O’Neill’s station (4YA) will shortly be one of the most powerful and efficient in this part of the world. Eight valves are expected any day, and the new 500 watt set will then be brought into operation. The whole of this large set has been designed and manufactured in 4YA’s workshop. There will be four (amplifying valves and two DV2 valves, worked from push pull transformers. The following stage will be a five watt, then a fifty watt, and this will pass into the modulating valves. It is the intention of Mr. O’Neill to have three modulators of 250 watts each. These valves are capable of working 30 per cent, over tlieir set wattage. The new generator is capable of giving an output of 1400 watts. This will allow of the station radiating a full 500 watts into the aerial when required. In the near future everything will be in working order. IN TOUCH WITH ARGENTINA. Mr. Ivan O’Meara, the well-known Gisborne amateur, has created a fresh record in long distance transmission and reception, by successfully maintaining communication with an amateur station at Buenos Ayres, South America. Mr. O’Meara first picked up this station’s call just after 7 p.m., and he immediately replied, his C.W. being picked up by the Buenos Ayres amateur, and from then on two-way communication was maintained from a period of two hours and ten minutes. Confirmation was afterwards obtained by cable. This performance completely overshadows any previous New Zealand amateur record, and it should take a lot of beating. Previous to this latest record, no New Zealand amateur transmitter had been able to make his signals heard further than the other side of the Tasman.

A question which is often asked is: “How is it that New Zealand amateurs are able to pick up hundreds of American amateur transmitters, and yet not be heard themselves by the Americans?” The explanation offered to this question is that failure is due to the great amount of interference which exists on the 140-200 metre wave lengths in the United States. This is brought about through a great number of stations all transmitting on the same wave length and causing considerable jamming. Not until the English amateurs used a wave length of 100 metres were they able to get their signals across the Atlantic. Previously they used wave lengths in the vicinity of 200 metres, which is identical with those used by amateurs in New Zealand and the United States of America. Maybe if New Zealand amateur transmitters experimented a little on the shorter wave lengths, they would be more successful in getting their signals further afield.. Mr O’Meara was transmitting on a 135 metre wave length when he established bis record, and on this wave length interference would be very slight, if any at all. Th a president of the Canadian National Railways is arranging to provide wireless receiving sets for 100.000 workers on the company’s lines. Broadcasting stations will be established at various points along the 22,000 miles of I line operated by the company, and receiving sets will be supplied at cost price. Mr. Spackman, IAC, of Auckland, has built a ten-valve super heterodyne, but so far has not had as good results from it as from his four-circuit Cockaday set. Only specially selected parts should be employed, in a super-hetero-dyne set. “BIG NOISE” EFFECTS. The following is from an English radio journal:—The “big noise” in wireless is becoming too commonly sought after nowadays. It may be all very well for the possessor of a set who is never satisfied unless he is filling his home with clamant reproduction from his loud speaker—regardless, of course, of sweetness of tone and sonority—but if the same individual conducts public demonstrations in the same way, the offence becomes nothing less than sheer abuse of the science, and the people who listen to it would probably be far more pleased had they listened-in on a simple crystal set. The limits of the set in use should be fairly recognised; it is bad practice to strain the installation by unduly high plate voltagehigh filament temperature, and tight coupling. That way lies trouble other than distortion, for the lives of the valves may be considerably shortened. These points should be borne in mind, particularly in the reception of broadcasting, and if really large audiences are to be entertained the best method undoubtedly is the use of efficient detecting and amplifying apparatus, together with a good power amplifier and several loud speakers connected in parallel. A loud speaker, it should be remembered. is capable of giving clear (reproduction only up to a point. Be‘yond that, when the volume of sound is too heavy, distortion plays havoc. If (every demonstration of wireless was (conducted on proper lines we should [very quickly hear the last of the

larity of wireless to the gramaphone. Under the right conditions speech by wireless is very much more accurate than by gramaphone, while the music of practically every instrument can, by its means, be reproduced with its true qualities and features preserved to an extent which most people would describe as perfect. That has never been done yet by the gramaphone. A GOOD SOLDERING FLUX. For soldering connections in a radio set it is advisable to use resin instead of an acid flux. The acid flux is easier to work with and for this reason it is more commonly used, to the detriment of any connection where fine wires are employed. The acid, besides corroding the wire, has a bad habit of “creeping,” which often provides a high resistance leaking path between connections. This is particularly noticeable when soldering connections to jacks. An excellent flux, having resin for its base, may easily be made by the experimenter. It is non-corrosive, does not “creep,” and leaves a neat-looking joint. This flux is made by dissolving resin in a small quantity of denatured alcohol. If the resin is powdered, it will be dissolved much more quickly. This flux should be kept in a corked bottle, and when used can be applied with a toothpick. “FIZZLING DISAPPEARS.” “Listening-in” with valve sets without the bugbear of high tension batteries, has been accomplished by two radio experimenters, Messrs. Dowding and Rogers, who, by means of a “stepup” transformer, are able to use a small current emitted from a lighted filament, with a new four-electrode valve to overcome its resistance (says a London report). This is regarded as the most important discovery since the advent of broadcasting, as it eliminates the distortion and “fizzling” inseparable from the use of high tension batteries. Mr. Dowding, who is a technician, formerly of the Air Force, explains that the invention reduces the detector and amplifier sets to the simplicity of a crystal apparatus, and overcomes the greatest defect in communication between aeroplanes. It also eliminates the airdriven, high-tension generators, which are constantly failing. Mr. Rogers was formerly with the Marconi Co.’s research stan.