Wireless

Hawke's Bay Tribune, Volume XV, Issue 125, 2 May 1925, Page 12

Wireless

DAYLICHT RADIO. MACLAURCAN GETS WASHINGTON Mr. G. D. Maclurcan, the Sydney radio amateur, sent and received messages by daylight on April 20th over a distance of about 10,000 miles. Groping shput iu the other on that day Mr. Maciurcan picked up UNKF. the naval wireless research laboratory at Washington, U.S.A. Actually, ho was trying to raise an English amateur, whose acquaintance he nad made—always at the distance of some 12,000 miles—when his friend, Jack Davis, of Vaucluse. rang up on the telephone to tell him that UNKF had called. Let Mr. Maclurcan tell the story:— “I answered them, and they came back in a few minutes, good clear signals. They moused: ‘Your 20-metre signals very strong hero. Had other tests, so could not come back at once. NKF wave. 20.8 meters. G.A. (go ahead).

“I told him his signals were very strong, and asked him for the exact measurement of my wave-length. 1 was anxious to have it measured exactly on the laboratory instruments, lie came back and told me, ‘Received you. F.b. (fine business). Your wavelength is 21 metres. You were sure f.b. during your 30 minutes’ test for English 2UD (the call sign of Simmonds, Bucks, England), but you are fading slightly now. Have you worked any other American station on 21 metres? What is your address? What city?’ “I answered his questions v and he told me, ‘Received all O.K. Please test for two minutes. Want to try another receiver. Will then let you go. How are my signals?’ ‘’l told him his signals were good, and he came back, ‘Received all. Please send V’s (3 dots apd dash) lor two minutes for test here. Good-bye.’ THE LONG WAY ROUND. “The remarkable feature of this result is that we were using a daylight wave-length—a 20-metre wave will not travel at night—and 1 still got Washington. This meant that our waves, both ways, must have travelled round the daylight side of the globe .nt that hour. The short way round to Washington was in darkness, so the waves went the 3000 or 4000 extra miles round the long way, going about two-thirds round the globe.

“We have proved conclusively already that 20-metre waves do not travel in darkness. In any case, our experience on this test proved it. If these signals had been coming from Washington to me over tho darkside of the earth they would have become stronger as darkness fell in Sydney. Instead of this, they actually became weaker as dusk fell here. “The importance of the discovery, some weeks old now that very short waves will travel by day is likely to prove very great in the commercial use of wireless. There will be a wave for daylight, and a wave for night, and continuous communication will be possible between any two places on the earth. “I was very glad to get Washington. Jljev take their job seriously in the research laboratory, and they do got waste time picking daisies. They e.idcntly attached some importance to tho two-way tests, and the good results on the short daylight wave. “I haven’t got England yet by day, although they have got me occasionally. 1 am sure we’d make the twoway connection yet. Then there remains only the voice. If we send that by day, we have done everything that radio can do anywhere. I’ll go on trving”. ♦ ♦ ♦ ♦ IN TOUCH WITH LONDON. A cable on April 17th. from London stated that the English wireless amateur, Mr. Morrow (G6UV), heard the Sidney expert, Mr. Maclurcan, just after 7 a. in. that day, for 15 minutes. The reception was extraordinarily (.lear and very loud. It was picked up on 20 metres. Mr. Morrow will look out for further messages during the week-end. Ho also hoard New Zealand, but less distinctly. Mr. Morrow says that he called Mr. Maclurcan for half an hour, but got no answering signals. Mr. Maclurcan told a Sydney Sun reporter that this cable referred to his transmission of Thursday, and it is interesting to note the increase in signal strength, in view of the fact that he was using the largo 90-foot aerial instead of the 20-foot one previously used. This was operated on a harmonic. Tho power used was the same as in the previous test, approximately 50 watts, but in the middle ol tho test a different transmitting set was used. It seems that this was an improvement, as the time given in the cable message corresponds to the time at which the second transmitter was used.