WONDERS OF WIRELESS.

New Zealand Herald, Volume LXII, Issue 19098, 17 August 1925, Page 6

WONDERS OF WIRELESS.

AMERICAN DEVELOPMENTS. SHORT - WAVE' DISCOVERIES. REMARKABLE RESULTS. Thero are upwards of 10,000 wireless experimenters in the United States, all combined in a Wireless Ilelay League for the purposso of exploiting the possibilities of tho shorter ether waves for commercial purposes. So enthusiastic are these workers that it is impossible for an experimenter to turn the dial of his receiver by even a half-metro at any time during tho day or night without establishing contact with two or moro experimenters. This information was given last week to the Sydney Morning Herald representative by Lieutenant Schnell, of the American Relay League, who was specially commissioned to make tests on short wave working during the voyage of the United States Fleet to Australia. " The amateurs have shown not only the practicability of using short waves for commercial wireless telegraphy, but they have demonstrated its absolute reliability for both day and night transmission," said Lieutenant Schnell. " This means that, instead of millions of dollars having to be invested in a plant for commercial radiography, the cost will only be a few thousands of dollars, and under the short wave system the transmission will not only be continuous throughout the 24 hours, but its transmission and reception will bo much moro rapid than is fit present possible under the long wavo system Experiments in the Pacific. " In the experiments carried out on the Seattle it was shown'that on the journey across the Pacific it was possible not only to keep in direct touch with Relay League experimenters in all the States of the American Union, but also with amateur experimenters in Britain. When within sight of the Australian coast I was talking in Morse with Mr. Gerald Marcuse (station 2N.M), Britain. Ho was transmitting on 43 metres and I was using 39 metres. Generally the experiments made between tho United States and Australia showed that 40 metres gave the best results for night work and 20 metres for daylight work. -"It is now generally established that in short wave work a shorter wave gives better results dn the period of sunlight on the area covered by the radio message. It will, however, probably be ascertained shortly that a general utility wave length between 25 metres and 30 metres can be utilised for both day and night transmission, though it is doubtful if such a wave length would bo as reliable as the longer one for night work and tho shorter one for daylight. The power used in transmitting from the Seattle was only 150 watts, and tho

energy used by the amateur stations of tho United States, with which I communicated continuously, varied from 1000 watts down to 20 watts." Picture Transmission. Lieutenant Schnell added: —"Another line which the American amateurs arcdeveloping to perfection is the art of picture transmission by wireless. Amateur experimenters are now able to transmit pictures of themselves, their machines,

and all surrounding objects to other amateurs equipped with receiving apparatus. This has also passed the merely experimental stage and I anticipate that when I get hack to Los Angeles two month? hence, I will be able to transmit from there to a station at Hartford, Connecticut —right across tho Continent —pictures which I have taken in Australia.

"I hopo shortly to bo sending pictures by wirolcss from the United States to Mr. Maclurcan, in Sydney. It may seem to some an idle fancy that telephonic wireless should be combined with picture transmission, but tho experiments re cently mado along those lines in tho United States have demonstrated conclu sively that it can bo done. It is now merely a question of perfecting the transmitting and receiving apparatus, then the owners of improved radio sets will be able, not only to hear sermons, political addresses, stage productions and grand opera, but actually to sco the persons entertaining them."