THE RADIO WORLD

Southland Times, Issue 19634, 30 September 1922, Page 9 (Supplement)

THE RADIO WORLD

“Valve.”)

NEWS, NOTES AND COMMENT.

(By

A lifeboat recently tested at Atlantic City was kept in constant telephone communication with the shore—six miles distant, without an aerial. A wire from the sending and receiving apparatus was run forward to the bow and connected to a special metal keel, and this, with two wires i;un along the sides of the boat, replaced the aerial. The result of these trials has led to the Coastguard Service considering the installation of a wireless telephone on all lifeboats. Then it would be possible to talk to men fighting the waves in a storm, whilst attempting life salvage. A huge wireless station has been started at Ruysselede, near Bruges, the aerial for which is to be suspended from eight towers a thousand feet high. Il is to be used for wireless communication between Belgium and Central Africa, and North and South America. A special feature of this station will be the employment of a new system of sending photographs by wireless. Photographs of writing will be sent, enabling long messages to be sent at a very hign speed, and drawings will be transmitted. This part of the work is being done by means of an invention of the well-known Belgian telegraph engineer, Monsieur Charbonelle, who took an important part in the early work of transmitting photographs by wire. The power used tor operating the wireless apparatus will be 1000 kilowatts—over 1300 horse-power. <&»<s><s> It is not often that father and sons have a common hobby, says the Glasgow Herald. But at the moment both the King and his sons are intensely interested in wireless. A wireless receiving set has been installed in Buckingham Palace and messages are picked up by the Royal party with all the zest of amateurs, while “listening-in” affords much enjoyment. But the best part of the announcement perhaps is that it is no elaborate and costly set. Part of it was “improvised**' by the King, who is, of course, very handy with tools, a marked contrast to the Prince of Wales, who strongly resembles his Royal grandfather, King Edward, in this respect. The Duke of York is much better able to help his father in hobbies that require a little ingenuity. The King often repeats with zest the anecdote of the Prince Consort, who tried to teach his eldest son to be useful with his hands. “But,” objected the little Prince of Wales, “I shall be King some day, so what, does it matter ?” Queen Victoria thought the observation “very characteristic of my son.” HINTS FOR THE AMATEUR. All hookups work better when assembled on an experimental table, with even loose association of parts, than when closed within a cabinet. Remember that when trying to imprison a good working set. An experimental table, with handy aerial ground and battery taps, plenty erf room to arrange instruments far apart, is one of the best assets an experimenter can bavc. Some of the finest working sets are located on such tables with the most unsystematic wiring you can imagine, but so perfectly are the parts balanced in their relation to each other that the owner would not permit a single wire or part to be moved a fraction of an inch. If you must assemble your parts -in a cabinet, try a temporary wiring before soldering connections. You may find that changes are necessary. Place your grid leak where it may be changed in value easily. This is an important. though often despised, piece of apparatus in any set. No two detector tubes are alike in any sense, and no two require the same grid leak values. When you change tubes, become acquainted with your set over again. You have changed the most important link in the chain. Every detector tube (even of same make) requires slightly different plate voltage, especially at critical points. You cannot change detector tubes on the same plate voltage as you can amplifier tubes. HINTS FOR AMATEURS. Amplifying transformers should be set af right angles to each other, well apart. Be sure your valve makes good contact with the holder. Bad contact causes noises difficult to trace. Unless the grid is connected to the outside lead of an amplifying transformer there will be no efficient operation of the valve. Using a series condenser, some sets work best with the condenser in the ground lead. Others are best operated with the condenser in the aerial lead. A rise in filament temperature one degree above the normal shortens the life of the valve 50 per cent. For loud signals on true note (on 600 metres) use a soft valve. For loud signals with the valve oscillating use a hard valve. The same valve will not bring in loud signals both ways. Extra capacity in the aerial is much more desirable than a condenser across the tuning coil to give the same capacity. Some amateur aerials use spreaders about six inches long. If spreaders at least three feet are not used absolutely no advantage over one wire is gained. Don’t use the water supply as a ground if you are near the tram lines. You will get quite enough induction and hissing without. Bury a sheet of iron or copper several feet below the ground and bring an insulated lead from it. Radio operators may calculate to an approximate degree the wave length of their antenna by adding the length of the antenna, the length of the lead-in and the length of the ground wire, then multiply the total length of all three by one and one-half. For example, the antenna of a set is 100 feet long, the lead-in is thirty feet and the ground wire twenty feet, making a total of 150 feet. Multiply the 150 feet by one and one-half, which gives the result of 225, the natural period of wave length of the antenna itself. FIGURES TALK. AIRWAY WIRELESS LANGUAGE. To overcome the language 'difficulty in the use of the wireless telephone on the International Airways a code containing standard phrases in English, French, and Dutch has been compiled by the aviation authorities of Great Britain, France and Belgium. With this code J;he only parts of a foreign language a pilot or ground wireless operator need know to carry on a conversation are. the numerals, the code consisting simply of the figures 1 to 85, each figure represents a phrase dealing with such matters as weather, illness, time, and position.

For example, the operator at an air station who hears “70” coming through the air knows to “Arrange for a doctor." The code number “44” is a request for the weather conditions and “48” conveys the news “The sup cK; -ving.”