RADIO TELEPHONY

Evening Post, Volume CXV, Issue 72, 27 March 1933, Page 8

RADIO TELEPHONY

ASTONISHING RANGE

The. fact that spoken messages were to be received in New Zealand by the .Radio Broadcasting Board naturally added very greatly to yesterday's pro: grammes, and the main stations were on the air all day, giving listeners up-to-the-minute news as it came through by morse from Mr. Stannago or rebroadcasting spoken messages. '/'All things considered, the installation came every bit up' to expectations,^ said Mr. W. M. Dawson, chief engineer for Philips Lamps, Ltd., who designed the equipment, "and any reception of tho spoken messages when the Southern Cross was 1000 miles out from New Zealand was remarkable, for the plant was primarily designed to enable Sir Charles to speak to Australia during the last two to three hours of the flight, say, over two or three hundred miles, and not for very long distance speech to New Zealand with the limited power available. It was, in fact, almost out of the question to expect rebrbadcasting strength of radiotelephony messages from tho aeroplane's equipment over 1000 miles, and that it came through as it did was surprisingly satisfactory." "SKIP DISTANCE." Apparently during the morning while the_ machine was within the effective radio-telephony zone about Hew Zealand the "skip distance" complication came in-as far-aa Wellington was .con-

cerned, but at greater distances, as in the far south, the messages were received satisfactorily. The same complication had been experienced during the trial of tho equipment on the flight from Wellington to Dannevirke, for though reception iv Wellington was poorish, in Southland it was reported "100 per cent, modulation and 100 per cent, readability,." and that was surprising in view of tho fact that the Southern Cross was flying at a very low altitude, down to as low as 20 and 30 feet from the water, not from choice, but from tho necessity of keeping below the heavy cloud and mist round " the coast. , »

Several reports had been received from direct listeners this morning1 that reception from the aeroplane was generally good, he said. In the far south telephony was well received throughout the trip, the first message coming through at 7.12 a.m., when the "skip distance" effect was becoming less troublesome. Heard direct in Wellington at 9.8 a.m. speech was good, but it suddenly dropped in volume; at 10.30 and again at 11 a.m. it was also quite good. At 1.54 p.m. telephony was very good, probably the best during the whole flight, and at 3 p.m. it was again quite good. The final message from Mr. Stannage, stating that they were just about to land, was received by voice in the South Island, something that was never expected. ENGINE NOISE. During the morning Mr. Stannage had reported that the wireless room — really nothing more than a fair-sized box, sound-proofed and lit by ; , a triple paned window —was. becoming' unbearably hot and that he had had to open the top slide to get some breathable air. It was quite possible, said Mr. Dawson, that the slide was not completely sealed and consequently the roar of tho engines was reaching the microphone. . ]

"Until we can check up With Sydney ire cannot know how Australia received the spoken messages," said Mr. Dawson, "but if tho equipment did tho job for which it. was intended as well as.it covered a. distance over which it was never anticipated it Would be audible, this first .trial of aerial radio-telephony in tho New Zealand and Australian zones can bo described as very successful."