WIRELESS IN WAR

Dominion, Volume 14, Issue 21, 20 October 1920, Page 2

WIRELESS IN WAR

REMARKABLE DEVICES

A THOUSAND WORDS A MINUTE

In the late war communication by wireless was brought up-to a remarkable pitch' of excellence, and some c-f its secrets havo been.revealed since the coining of peace. The public thus have some knowledge of how the whereabouts of the enemy was discovered by tho interception of his wireloss messages,' cf the communication between observing? aoroplnnes and the guns, nnd of the control from I heir bases in (lei-many of raiding .airships. Demonstrations have l>een given recently. also of direction finding by wireless (says a enrrespendent of the London -"Times") - If is now intended to- equip- Ihenriny with wireless on a far wider and more general scale than' hitherto.

l-'roui the nature of its work as a lighting machine, it is essential that the army- should'have wireless equipment. «t' a distinct and definite pattern Nevei n ns high speed transmission more noeded (han in the midst of a general attack. There are instruments nt Woolwich that have actually transmitted messages at the rate of over n thousand words n minute. ' The application of such appliances 'to'the transmission of Press-mes' sages would revolutionise daily newspaper journalism.

In one of the rooms at Woolwic there is laid out a miniaturo wireless direc-tion-finding set. with which one may perform the exact operation in little of discovering the whereabouts-of another station, whether it be on sea, land, or in tho air, which is sending out messagos. The direction-finder is situated nt a fixed spot on a- map, the distant station is moved, about anywhere one pleases on tho same map, and the sound waves picked up from it, varying with the movement,'lead inevitably to the nccurato determination of its position. The principle of this revolving form type of direction-finder, turns on the-properties of a. closed locjp of wire. When'.'the closed lo«i forming the wireless receivI ing aerialls'turned'edge oil to the direction of. the trnnsniitti.'ig station it'will receive maximum' signals, and' when turned at. right angles lb tho transmitter the signals fade out or are reduced'to a minimum, thus'determining the'direction of the transmitting station. . With two -or more of these receivers' working in cooperation, their lines of direction have a point, of ' intersection which determines the, exact position of. -the transmitting statdori. "The early revolving forms in use during the ' war were about 10ft. to 15ft. square, and were sonviwhat clumsy. The latest pattern is aboii'.l one-seventh of. that size. It has a rang* of 2,50 miiles, and is accurate to one degree.

In another room in the experimental station there is a remarkable instrument which transforms. ordinary ground-line telegraphy into wireless. There is no limiil to the distance from which the original messago mav bo received so long as the sender is connected by groundlines to the wireless station. All he ■ need do ig to call Tip the latter and stato that he wishes to begin to send. The power at the wJreless'st/ition is set. in-motion by flu engineer. -nn'd a green light switched on in the operaiojc's cabin llells him that all ,is ready. He then begins to tap out .his telegram, or send it by the Wheatstone machine, and- it passes into the wireless station .as. it is telegraphed and oir* again in wireless w;avcs, the transformation having been effected, by the machine itself- without human aid. ;.-■[■' ■

Without going further into technical details, iti niay.be said'that wWi regard to transmission no<,.difliculty is anticipated in controlling -the -largest .power valve sets at speeds of 450 words uer minute by. means of ordinary post office apparatus. The receivers indicated will be prnciiicnlly iknmune from interference, except, of course, from- stations -opernt-, he on the same' wave length, and ■they Will lip.'capable of. ilealing-. with traffic at iSO words per-'luinnte-. when using .sfniulnrd -post, office recording instruments,. ;,.-. . .., ;•■•••.•■ :-.-.■

Ano'jihb'r instrument, seen .at Woolwich' is .'an amplifier,-, which enables -the--.re-' '.ce-ive'i 1 . of messages, to-cut out all -waves save.that lie!wishc;S.'toih'ea.r. -and to increase the intensity of -the desired signal.'' It has. been..brought i'o auch a. pitch of perfection, .in so far-as its, nowe'rs of filtration are concerned, that its user can listen to. a sending station hundreds <rf miles away, undisturbed hy ilie working of .another w'reless set- in. the same room whore ho-is-employed.