Tower gremlin claim

Press, 23 September 1987, Page 1

Tower gremlin claim

By KAY FORRESTER The Victoria Square tower proposal may haunt Christchurch City councillors for some time and a retired television engineer suggests the structure might conjure up a few more ghosts if built. Mr John Ryan, who spent 40 years in the television installation and electronics industry in Britain and New Zealand, believes the tower would have television viewers seeing double if it was built as suggested in Victoria Square. Very strong signals would be reflected off the tall structure, he says, interfering with television reception for a radius of four miles, and perhaps up to 10 miles. The reflected signals

would produce "powerful ghost images” on the screen. A ghost image was a double vision effect of figures on the screen having ghost figures to their right. “The effect will be quite a disturbance to the viewers. I believe up to half the city and suburbs would be affected,” Mr Ryan said. Some people might be able to reduce the interference to reasonable levels by installing directional aerials for their television sets, he said. Mr Ryan estimated the cost of installing and adjusting a directional aerial about $2OO. Christchurch enjoyed good television reception because it was flat and did not have any

high masts and tall chimneys which plagued viewers overseas with ghost images. Mr Ryan considered a chimney 45m tall (the tower would be 167 m) could cause Interference. However, the prospect of the tower in the middle of Christchurch did not unduly concern the Acting Controller of Broadcasting Services at the Broadcasting Engineering Centre in Wellington yesterday. Mr Trevor Archer said a tall, slim tower would produce only “minor local shadowing” in television reception. Directional aerials would indeed help relieve the shadowing, he said. Further reports, page 8