Radio Round the World

Radio Record, Volume II, Issue 5, 17 August 1928, Page 3

Radio Round the World

\.. T is interesting to notes that there are two stations in United States, now broadcasting television, but results cannot be depended on. Television is now where radio was prior. to 1920.. QGTRANGE as it may seem, there are many deaf persons to whom radio is audible. In fact ear specialists have even prescribed four or fivevalve sets as a cure for deafness, This can be understood: when one yealises that a three-valve set ampliflies vibration 15,000 times a second. N America 125,000. persons are employed by radio. ° N many ways the short wave bands will always be unsuitable for general broadcasting. For instance, there are times during which a station broadcasting on a certain short wavelength could not be received by any receiving station nearer than 600 miles. This would necessitate varying . wavelengths which would naturally cause much annoyance to -listeners-in. HOSE. who picture the North American Indian as a wandering; unlearned hunter of the plains, would be surprised to learn that a member of one tribe in South Dakota, houses in his tepee a £45 radio set. He is a well-educated chief, a master mason, and owner of an 800-acre "wheat ranch. SHoRT wave coils built into a vacuum tube and mounted on a standard: UX basis are among the latest radio novelties appearing on the American market.

(THE terms "antenna" and "aerial" do not heve the same meaning, although usvally applied to the one and same piece of apparatus. The term ‘"‘aerial"’ refers to the air-cer-tainly the broadcasting stations use aerials, -so do most receiving stations, but these latter are not without exception. One hears of "loop aerials," and "underground aerials. " Strictly speaking, these latter are not aerials as they do not project high into the air. The American has applied the general term "antenna" to any apparatus for receiving signals transmitted from the broadcasting stations’ aerials. Thus it is more exacting to speak of aerial antennae, loop antennae, and ground antennae. This distinction is worth bearing in mind when reading American: wireless publications. : (SHICAGO has the reputation of being the centre of the world’s most congested radio district, there being nearly 220 active broadcasting stations in the vicinity. xs DISCOLOURED ebonite panel *® can often be made to look like / new by the application of a little lubricating oil rubbed in with the finger-tips and polished with a soft duster. HE old story of the thoughtless boy who threw stones into the frogpond is not without modern applica-

tion, especially where loudspeakers are concerned. It is possible to get tremendous power on a loudspeaker from a local station. If you wish for quieter reception, control your output, don’t put the speaker on the window-sill so that the unwanted volume may float out on the still night air. A grand finale played at "10 p.m., studio time"? by a full band, received at full strength on several valves, and put through a powerful speaker, would probably not be welcomed by a sufferer just dosing, or by the mother (perhaps the father) of a young waking baby. Make radio a joy not a torment, and think before the loudspeaker goes on the window-sill.

HE most satisfactory method of volume control is to use a high resistance potentiometer instead of a grid leak, the grid connection being hade to the slider of the potentiometer. oe T is reported that 2000 neon valves, an essential of television, were sold in New England (U.S.A.) within two weeks ot the first broadcast of television from a suburb of Boston. HEN constructing a set it is a good idea to keep handy a voltmeter or electric torch bulbs. With vese the voltage on each point, or if bulbs only are available, on the filament points of the valve base. can be checked. before the valve is inserted. While the voltage on the valve filament and of the average torch bulb are about the same, there is a difference in price.

ROADCAST in Scotland is being designed to supplement work in the school classrooms. This takes the form of a series of special demonstration transmissions for the benefit of teachers attending the Summer School at St. Andrews. TALKS on interesting geographical and social subjects have been arranged by the British Broadcasting Corporation. One of the latest talks was "Women’s Life in New Zealand," specially addressed to the young would-be immigrant. F such a thing as "wired wireless" can exist, then it exists in America. The system is really quite simple. It consists in attaching a radio transmitter to the telephone lines and sending signals per this medium through the country. On aceount of the high frequency-of the radio signals, they do not interfere with the ordinary use of the telephone. This system is gaining ground in several parts of the world, but that it can be merely supplementary to existing systems is obvious. N ultra sensitive seismograph (instrument for recording earth«yakes), operated by radio, has been devised. .As it is able to measure a displacement of condenser plates as minute as four-billionths of an inch great things are expected in the ‘way

of recording and predicting earthquakes. POINT worth remembering in installing a radio set is that holes

in walls are easily made, bué not so easily filled. Holes, especially in outside walls, do not improve the value of a house.