Mercury (Hobart, Tas. : 1860 - 1954), Thursday 7 March 1912, page 8


WIRELESS EXPERIMENTS.

A MELBOURNE INVENTOR. A SENSITIVE DETECTOR.

Probably but few people are aware that for several years Mr. Henry Sut-ton has been carrying on important re-search work in wireless telegraphy at his private station in Melbourne (says the "Argus"). Mr. Sutton has in-vented a now detector, which greatly facilitates the reception of messages. Not only has the sensitive detector a far greater range than one less sensi-tive, but it records more distinctly, the messages which the less sensitive can also hear. The work done in the test months was in no wise exceptional, for very similar results are to be obtained nightly with Mr. Sutton's installation. Last Tuesday night, for instance, a visitor taking up and putting on the second telephone headpiece while Mr. A. E. Sutton was listening for calls could hear at different times between 10.30 and about 11.45 such things ns a conversation between H.M.S. En-counter, lying at Hobart, and H.M.S. Cambrian, which had lately left Sydney for Hongkong; or calls from the Orso-va, which had just .started for London from Brisbane, and must havo been about 800 miles off, the airway »of its message to Melbourne being almost wholly overland, and, therefore, a moro difficult airway than if it had been entirely oversea. Many other calls and messages weroe also to be heard during that hour and a quarter, including calls fiom the Westralia, which had only just left Hobart for Sydney, from the Grantala, then cm her way to Sydney from Melbourne, and from the Hotel Australia in Syd-ney. Even to one unused to listening for wireless maessages, the Morse dots

and dashes of all those calls and talks, came with wonderful clearness through the new receiver. It may be mention-ed that, in addition lo the delicate electric measurements necessary to the working out of the principle of the new detector, Mr. Sutton made last year a number of photo-micrographs illustrat-ing the action of electric oscillations in relation to his invention. These are to be published with the technical re-port ef his investigatation.

From Julvyto October last tests were made with the new detector every night nt the Erskine-street station by Mr. A. E. Sutton, the inventor's son. The results have been tabulated, and they are eloquent of the detector's efficien-cy. As an interesting and suggestive

sample, we may take the results ob-tained for the half-hour after midnight on tho night of September 12, 1911. The follow in*; tln'ps wore then off tho west mid smith-west coasts of Austra-lia at the- tlislances in miles stated: -

.S.S. A«c.itnus, l,2d0; s.s. Suovie, '1,-100; .s.s. China mid .«.s. Scharniiorst.

1,000: and tho s.s. Osterley, 1.00O. With tho iipw detector thp calls of all tlie-e ve--els were distinrtly he.-iid in Melbourne' Again, on tho pievious 28th of August, at a little morr I linn 20 minutes nast midnight, the s.s. Ka-roola was heard l.C.OO milps off calling tho s.s. Omrah, which was about 2,C0()

miles from Melbourne, and tilt» Omrah | was also he.-titl answering, though but faintly. Thp longest ra URO call that could bo definitely delected during the months of trial was one heard about 8 .o'clock on tho night of August 8 la«t. It was the Suovie "calling "nil .stations." heard nt the enormous distance. (Tor wireless) of 2,397 miles.

The new receiver evidently does good average work at 1,000 miles, detecting without difficulty calls made by such vessels as H.M.S. Powerful from har-bour nt Brisbane or Wellignton. An operator nt tho "Erskine-street station may bo pardoned n feeling of suprem-acy .is ho hears, with the now receiver, ships vainly calling: to each other. Sometimes, while ships try, try, try, mid fail to get into touch, ho can note every word they sand out. Two ships have been heard for a full hour endea-vouring to understand each .other,-so that a message might be sent to Syd-ney mid tltonco ovcrlmid to Mel-bourne; every word from both ships being actually received in Melbourne with tho aid of tho new detector. In one case- two ships wero between Tas-mania and New Zealand striving to got one codo word tliroii"-h. The word was repeated -15 times beforo tho recipient sh'** managed to catch it. Yet that word was henri! Iho 15 times in Mel-bourne. "Wireless communication be-tween tho ships was more or loss block-ed by distant electrical disturbances in tho atmosphere known as "static,*' but the neillelectric ear of Mr. Suttoton's receiver could pirk out tío codo word in snitp of the "static." As can eas-ily bp understood, sensitiveness on the part oí the detector or ear of the» wire-less apparatus is n mum criterion of

its effectiveness and Mr.- Sutton seems with his new discovery to have found out how to construct an electric ear   that can hear messages too faint and too distant for other receivers to note.