TESTS FROM AEROPLANE

Daily Telegraph (Napier), Volume 59, Issue 47, 27 March 1930, Page 12

TESTS FROM AEROPLANE

SHORT-WAVE TRANSMITTER. Successful tests with a short-wave veceiving and transmitting set were carried out by Messrs J. Trenwith and J . Walker in one of the Auckland Aero Club's aeroplanes at Mangere. The tests demonstrated the value of radio to aircraft and, it is understood, were the first experiments of their kind to be conducted in New Zealand. The set, which was designed and bnilt by : Mr Tremvith, will be carried hy Captain Hewitt on his non-stop fliglit from Dunedin to Auckland. Captain Hewitt's call-sign will be XZAAR. , Thp first of two tests was conducted by_ Mr Walker, whose signals were re1 ceived at ZLW, Wellington. It was hoped his messages1 wonld be received at ZLB, Dunedin,, but he was not successful in this respect. Mr Walker's own call-sign was ZLIFL. Listening 1

from the grounds, Mr Trenivith obtained a perfect reception. A second test was carried out by Mr Trenwith, who, although one of the valves of the set failed, successfully transmitted messages to ZLW Wellington. Mr Trenwith' s call-sign was ZLIFX. With only one valve, his ontput power was redueed to three-quar-ters of a watt. His aerial power was .3 of a watt, with which he covered 400 miles. Thus with an aerial pow;er of one watt, he would he able to transmit a distance bf 1300 miles. With the operation of only one - valve, Captain Hewitt would be in" touch with either Wellington oi* Auckland during his proposed fligh't, The portahle set weighs only 191bs, The aerial is strung between the tips of the wings and the tail of the aeroptane. The plane during the test was flying .at a height of 5400 feet. The wave-length of the set is 36 metres.