WIRELESS INTERFERENCE

Waipa Post, Volume 48, Issue 3470, 24 May 1934, Page 5

WIRELESS INTERFERENCE

CAUSED" BY POWER LINES

DISC STRAIN INSULATORS. In view of the discussion on the subject at last meeting of the Te Awamutu Power Board, the following is interesting:—"i would like to comment on the statement made by your engineer at your last meeting, that veiy little interference arises from your Board's power lines," wrote the deputy radio inspector, Hamilton, to the Waitomo Power Board meeting held on Monday. "Quite on the contrary it can safe, ly be asserted that a very large proportion of the electrical interterencc which mars reception of listeners in both the Otoiiohanga and Te Kuiti districts arises definite.y from the 11,000-volt lines. "The results of my officers' investigations into various complaints were communicated to your Board's engineeis in May last year, in which memorandum the opinion was conveyed that the majority of the trouble was arising from disc type strain insulators. It has been with due appreciation of the possible financial and technical difficulties in effecting a definite cure, that the matter has not been stressed further and that the results of these investigations have not been widely broadcast amongst listeners. It is apparent, however, that this silence has been generally interpreted as one of inaction on the part of this Depaitment. In the specific case mentioned by you;) engineer a special investigation was made, and as a result it was revealed that the fault was emanating from your 11,000 volt lines.'" The engineer said he had investigated the matter, inc.tiding the disc insulators, very thoroughly since the memorandum had been received—on the piece of line from the Waitomo Lime Company to the saleyards, and also at Otorohanga. He had examined these lines and the disc insulators, and the result was nil—he found nothing likely to be a source of wireless interference. He had been taken to task over his statements in regard to transformers and general wireless interfei ence, but these views had been drawn from a paper at the last Engineers' Conference, and had been fully discussed by the engineers. Since the last tests had been taken no data had been made available for him, and he was groping in the dark. He asked that the Board should ask for these details so that he could find out the true position. Mr O'Connell asked regarding the disc' insulators. The engineer replied that he had examined these, and as far as he could see it was not possible for them to cause interference. If the trouble was coming from them, it must be something inherent in the design. A'l the original construction work was done with this type. He asked that he be given authority to do a certain amount of experimenting. This was granted on Mr Simms' motion, who suggested Otewa as a starting point, while it was decided to ask for the data obtained in the last tests by the Post and Telegraph Department. At the previous meeting of the Board the engineer stated that the greatest cause of interference lay in house appliances, and the great bulk of the troub'e did not lie, as most people supposed, in the transformers. A certain amount came from the power lines, but it was a small proportion..