WIRELESS TELEPHONY.

Taranaki Daily News, 16 July 1919, Page 7

WIRELESS TELEPHONY.

A ROYAL ATR FORCE TRIUMPH, General Seelv (British Air Minister) recently told the House of Commons how the Royal Air Force produced the perfect wireless telephone. In the system tlio receiver of an ordinary, wireloss telegraph set can be adjusted to,receivcd the spoken message, as well us (he Morse code, from a telephone transmitter. The Germans knew this, and at nine o'clock every night for a very great distance on the Western front tuned their receivers to intercept the British station ut Dunkirk.

The British quickly found this out and played selections on the gramophone—heard by vessels in the. Channel —including "Winding up the Watch on the Rhine,' 'and "Another Little Drink,:' The Huns kesnly appreciated the second song, but the opening bars of the first one were always interrupted by "•jams," Fritz getting very angry with the British humorists.

The perfection of the telephone has been the result of very extensive work at the R.A.F. experimental station at Biggin Hill, following original research work by the R.F.C. at the Array experimental establishment at Woolwich. As far back as March, 1918, a British squadron of Bristol fighters operating over the German lines was controlled by the flight leaders by telephonic orders to the pilots of the flight. A few weeks later a telephone conversation was held with the pilot of a machine flying more than 100 miles from the control station.

To-day conversation can be held with machines more than 150 miles away. The system is so perfect that a method has been introduced whereby trailing aerials in machines are no longer necessary. A minjature exchange has been placed in the pilot's cockpit by which the pilot can talk to his passenger, to another machine, or to the ground by operating a switch. Conversations can also be held without talking through the iips at all. A special appliance, which includes a microphone, is placed round the pilot's throat with connection to the observer's receiving headpiece. When the pilot speaks, the microphone converts the movements of the throat into words and transmits them to the observer, much as a gramaphone converts the marks on the: records into sound. Tho great advantage of this invention is that the pilot's message is not drowned by tho roar of the engine. The great merit of wireless telephony from a military air point of view is that the pilot of a single-seater scout pan direct all his attention to manoeuvring end fighting his machine instead of having to maintain communication with the land or his fellow pilots by working a wireless key. i It also - simplifies the training of pilots, for it is very much easier to teaeh them the correct way to ÜBe a telephone transmitter than to teach and maintain efficiency in wireless telegraphy. General Seely could also have ppoken of the wonderful development which has taken place in the R.AJ\ with regard to ordinary wireless work. It is not generally known that British machines were using wireless in 1912 and on the outbreak of war a numbel of R.N'.A.S. machines were communicating by means of it, thanks to the naval officers and operators, who carried out the pioneer work. ' To-day its capabilities are practically unlimited. It is being used as a means of directing machines in flight. Waves sent out by two or more stations on n wide base and the exact location of which ia known to the pilot are "collated" in n machine fitted with the necessary ap» naratus, and enable the airman to determine his exact position, although he may previously have lost all direction and locality.