RADIO EXHIBITION.

Gisborne Times, Volume LXVIII, Issue 10748, 20 November 1928, Page 5

RADIO EXHIBITION.

WIRELESS NOVELTIES. LONDON, Sept. 27. The sixth radio exhibition at Olympia attracted great crowds of wire less enthusiasts. The 200 exhibitors were drawn from all parts of the world, and the wares displayed gave astonishing proof of the growth 6! the industry in a few short years As a consequence of recent litigation, whereby Marconi’s royalties were challenged, there was evidence of falling prices in every direction. Manufacturers admit that ihe day of the £3 three-valve set is at hand. The crystal set is passing, but loudspeaker sets are “booming,” and radio may gam even larger popularity when radio pictures are trans nutted regularly. Newspapers have already used radio pictorial trans mission, and radio pictures in the home with a wireless receiving set are within the possibility of earlv invention. -The “talkies” threaten to revolutionise the cinema industry, and “radio pictures” may serve 1 a similar purpose in the realm .of wireless. Television receivers were sold at Olympia for £2O. The smallest portable set in the world, a one-valve receiver, measuring eight inches by six, was a novelty at the exhibition. It costs £5 ss. and it works excellently within a few miles of the transmitting station. Three-valve portable sets can -be bought for £lO 10s, and a first-class five-valve portable set for £52 103. An interesting- technical device shown was the pentode, a ; five electrode valve, with three grids, which can be used with any wireless set by fitting into the valve socket. It has a terminal at the side which must be I'fined to high tension. Added to ft set which i$ giving poor reception from a distant station it brings the" volume of sound to full strength. This is sold for 255, no extravagant price, seeing that the pentode doe? the work of two ordinary valves,' bringing a three-valve set up to live-valve efficiency. The all-from* the-mains receiver is also popularMany sets' were shown which dispensed entirely with batteries. They ore relatively expensive at present. The General" Electric Company charges £3l 10s for an “all electric three,’ suitable for working from 200 to 260 volt A C. mains. ' An Empire Screened Four Receiver. made by Burndepts,. . has been made for overseas listeners. The re coiver covers the wave bands of 2G-4B and 220-56 metres, and thus is suitable for receiving short-wave i.‘" tele ' phony, from, 0 S. \V. or from Ameri can or Australian stations. Broadcn sting outside the Empire is carried out on the 250 to 500 metre band Another set designed for Dominion use is the Cosmos ultra-short wave set. made by Metropolitan-Vickers.. In loud speakers the chief interest is in those of the moving coil type, which give exceptionally good reproduction of high and low notes, but also produce a large volume of sound, without distortion. At the moment 2,500,000 British homes have wireless installations, that is one household m every three, compared * with ono in five in tho United States. On .a great occasion 20,0(X),000 listeners-in may receive a programme.