WIRELESS TELEPHONY

Dominion, Volume 12, Issue 248, 14 July 1919, Page 5

WIRELESS TELEPHONY

A ROYAL AIR FORCE TRIUMPH., General Seely (British ' Air Minister) recently told the House of Commons how tho Royal Air Force produced tho perfect wireless telephone. In the system tho receiver of an ordinary wireless telegraph 6et can bo adjusted to receive tho spoken message, as well as the Morse code, from a -telephone, transmitter. Tho Germans know this, and at. nine o'clock every nijht for a very great distance on tho Western front tuned their receivers to intercept the telephone messages, from the British station at Dunkirk. The British (illicitly found this uut and played selections on She gramoph me— heard by vessels in tho Channel—including "Winding up the Watch on tho Rhine" and "Another Little Drink." '.ihe Huns keenly appreciated tho second str.g, but the opening bars of the first one rero always interrupted by '.'jams," Fritz getting very angry with tho British humorists. •' The perfection- of, the telephone has been tihe result of very extensive work at the R.A.F. experimental station at Biggin HUI, following original research work by Hie I'.F.C. at the Army experimental establishment at Woolwich. As far back as March, 1918, a British squadron of Bristol fighters operating over tho German-lines was controlled'by the flight leaders by telephonic orders to the pilots of tho.flight, A few weeks later a telephone conversation Mas held with the pilot of a machine, flying n.oro than 109, miles from.the control stetion.

To-day conversation can be held w'ith machines more than 150 miles away. The system is so perfect that a method lias been introduced whereby trailing aerials in machines are no longer necessary. A miniature exchange' has been .nlaced' in the pilot's cockpit'by. which the pilot can talk, to his pn.sfc-n.ger, to another machine, or to the ground by operating a switch. Conversations can also bo held without talking through the lips at all. A special appliance-, which includes n mic•rophone, is placed round tho pilot's throat with connection to the observer's receiving'headpieco. When the pilot speaks, tho iiiicrophouo converts the movements, of the throat into words'nud transmits them to the observer, much as a gramophone converts tho in|rks on the records into sound. The great advantage of this invention is that .the pilot's message is not. drowned by tho roar of tho engine. Tho great merit of wireless telephony from a military air point of view is that the pilot of a single-seater 6cout can uireoc all his attention to manoeuvring and fighting his machine instead of having to mafeitain communication with tho land or his fellow pilots by working a wireless key. It also simplifies tho training of pilots, for it is very much easier to teach them the correct way to use a tolephone transmitter than to teach and maintain efficiency in wireless tolegraphy. General Soely could also have spoken. of the wondorful development which has taken place in tho R.A.F. with regard to ordinary wireless work.' It is not generally known that British machines wero iisiug wireless in 1912, nnd ou the outbreak of war a number of, R.N.A.S. machines wero communicating by means of it, thanks to the naval officers and operators who carried out tho -.pioneer work. To-day its. capabilities aro practically unlimited. It is being used as a means of directing machines in flight. Waves sent out by two or more stations oh a wide base and the exact location of which is known to the pilot aro "coßtited" in a machine fittea with tho necessary apparatus, and enable tho nifmnu to determine his exact position, ' although he may previously nave lost all direction and locality.