RADIO NOTES.

Manawatu Standard, Volume XLVII, Issue 28, 31 December 1926, Page 3

RADIO NOTES.

INFORMATION SERVICE. [By "q!r.M.”] In Denmark during the past year the number of licenses has increased from 30,000 to 90,000. Last month was tho 25th anniversary of the crossing of the Atlantic by wireless. In December, 1901, throe dots came from England to Signal Hill, St. John’B, Newfoundland being tho first signal of any kind to span the ocean. The Australian station 3AR hoped to bo using greatly increased power by the end of this week. When on full power crystal control will bo employed to keep the station on its proper wave-length and to stop any blanketing effect tho high power might induce. Mr J. Prentice recently spoke to amateurs of the Auckland Radio Association, and later was welcomed at a radio dinner given by the radio dealers of Auckland. Many matters pertaining to radio in Now Zealand were discussed at length. RADIO—PAST AND FUTURE. Another year has gone by and Now Zealand is on tho threshold of another year which we liopo will prove even more prosperous than the past, and that a much better broadcasting service will be in vogue before another New Year arrives. Yet even during the short 12 months constant listeners must have noticed great changes throughout New Zealand. Even if broadcasting as a whole has not improved as much as promised, a great change has occurred in the listening world. A movement has been started whereby they may endeavour to combine and use their united efforts to secure a better service and to uphold their rights as licensees. Tho erection of three modern broadcast stations in the Dominion, oven though they may not be as efficient as they could be, has been a stop to the good, and before tho winter another 500 watt station will bo ereoted in Wellington, whereas in tho beginning of the year there wore only some 3000 odd licencees.

Radio has assuredly como to stay, but it is at that critical stage when a poor or badly managed broadcasting sorvico will hinder its advancement for many months. Broadcasting in tho Southern Hemisphere has seen a decided improvement during the last year, both in tho actual transmissions and in the number of hours extra in the programmes. Australia at the present time broadcasts from seven o’clock in the morning to midnight with short intervals. Country listeners are more and more being catered for, and radio to them has indeed come as a boon. In the commercial world great strides have been made in international communication. Tho great British station at Rugby, GBR, i s now daily flashing nows around the entire world, so that news of world-wide interest can be known in every corner of the earth within a fow hours or even minutes. The largo beam stations have yet to be proved, but there is little doubt tliat within a very short timo new records will be made and broken for fast and sure radio communication throughout our Empire. Again, short wave communication has hardly been touched and fvhat another year may bring forth in this line can hardly be prophesied by the' mere amateur. The design of the receiving sets has undergone a considerable change. Multivalve sets are now very common, wheroas a fow years ago a six-valve set would be hard to find in Now Zealand. The old coil mounting on the outside of tho cabinet is disappearing and is either being hidden in the cabinet or done away with altogether in the form of the variocoupler type of coil. The controls also aro more perfect and accurate, and are fewer in number thus assuring greater simplicity; tho day when it took one at least half an hour to tune in a station has gono, and one may now bring in any one station by simply turning one or two dials to a constant position. Not only are tho sets more simple and selective in their operation, but they are being turned out in handsome cabinets that could be placed in any drawing room to advantage as a

piece of furniture. Indeed, radio has passed from the schoolboy hobby stage and is now ranking equal to many other musical instruments. The invention recently of non-squealing receiving circuits by Sir Oliver Lodge will bo a great step towards perfect reception, while the ever popular non-radiating set has also reduced interference by squealing valves considerably. As far tfs the future of wireless in New Zealand is concerned, things are looking a trifle brighter. The fact that there are well over 10 000 licensed listeners in the Dominion and some 600 radio dealers shows that a good broadcast service must bo in vogue or sorious injury will bo dealt tho radio world. RADIO 2GB. Tho Theosophical Broadcasting Station 2GB, Sydney, at present uses a power of 3000 watts on a wavo-length of 316 metres. It is designed to use an output power of 20,000 watts. Several times the latter power has been used in tests. Rt. Rev. G. S. Arundale, M.A. LL.B., D.L., on the ‘official opening night stated : “2GB is established to broadcast brotherhood. Political talks, religious talks talks on Australian problems will bo heartily welcomed. Beautiful musio will bo the heart of tho programmes.” \ Carbon microphones aro used in the studios at present, but magnetic microphones are to bo employed for broadcasting church services, etc., on acoount of there being very little “hiss” in these instruments. Tho first stage of tho transmitter uses a 240 watt valve, the second a 480 watt, and tho third a 35,000 watt valve that is water-cooled by means of 200 gallons of cold water an hour. In addition powerful air blasts aro empjoyed as well to keep this giant from becoming too hot. Like 3AR, crystal control is to bo em ployed as soon as a definite wave-length is obtained from the Post and Telegraph Department. By this means it is impossible for the wave-length to vary the least fraction from its proper one, thus assuring perfect transmission in this line.

Wireless and sound currents are combined when they aro both of very small power; the combination is amplified to tho desired power. The sound currents are reduced in strength to obtain clear transmission, and then passed through a ono-stage amplifier to the modulating valves having a power of 10 watts. Even though it uses so high a power 2GB causes no interference. Numerous tests have been mado close to the station, but practically all other stations could be tuned in while 2GB was working. . ( 'llio station is hoard exceedingly well all over New Zealand and right throughout Australia, On a recont full power test, full loud speaker strength was obtained from the station in broad daylight in Queensland. WAVE TRAPS. Speaking to a press reporter, Mr R. Gibbs, chief telegraph engineer, stated: “The separation in frequency between the four principal centres in New Zealand is very much wider than what exists between a largo number of tho American high power broadcasting stations. Those with selective receivers find no difficulty in choosing between stations. Some people right alongside the Auckland and Christchurch broadcasting stations can, with suitable arrangements tune out the local station and receive other Now Zealand or Australian stations. In some countries where a number of broadcasting stations aro found in tho same area very largo use is mado of what are known U 3 wave traps, which are simply oscillating circuits connected between tho aerial and tho receiver, and which can readily be tuned so as to reject any signal not desired, leaving the listener free to tune tho apparatus to the desired signal. These are largely used in American cities whero more than one powerful broadcasting station exists. Almost all radio magazines describe wave traps suitable for broadcasting work, and how to install them.”