New Zealanders Make 50m Toll Gills A Year

Press, Volume CI, Issue 29747, 14 February 1962, Page 7

New Zealanders Make 50m Toll Gills A Year

New Zealanders are now making more than 50.00.000 long-distance telephone calls a year and the figure is increasing at the rate of about 5,000.000 annually, according to Mr R. Cascey, supervising engineer on the staff of the regional engineer at the Wellington Post Office. Mr Cawey revealed these facts when he presented a paper on “Carrier Communication Systems” at the annual conference of the New Zealand Institution of En-gin«-»r<s in Christchurch.

During busy periods. Post Office toll operators were now handling about 40.000 calls a day and those in Wellington about half that number, he said, and special facilities had to be provided to enable ai'h large numbers of calls to take place over the long distances concerned In 1928 the electronic valve was used for the first time to enable a number of conversations to take place simultaneously over a single pair of wires New Frequency

“Under this system. e?ch voice is changed to a new frequency so that it may be separated from the others .at the far end of the circuit It is rather 'as though the voices of four bass singers who were all singing at the same time, were changed so that one was a bass, another a tenor, the third one an alto, and the four'll a soprano.” explained Mr Cassey “Under these conditions each voice

may be readily distinguished. “In the carrier ayatem. a Somewhat similar process takes place, each voice being returned to its normal pitch by electronic means at the far end of the circuit.” Although an infinite number of conversations could be separated by this means, the total number of conversations which could be transmitted over a single pair of wires was limited to about 16. However, a larger number of conversations could be accommodated if signals were sent along coaxial cables or over a radio link 960 Ctrenita During 1961. coaxial cables had been laid between Auckland and Hamilton and Palmerston North and Wellington, and 960 telephone circuits could be accommodated on those cables. The cost of the cable worked out at about £3OOO a mile and the coot for the complete Palmerston NorthWellington section, including carrier equipment, was £670.000, said Mr Cassey Today there were about 220 telephone and 175 telegraph circuits operating over the . trunkline system and any Interruptions to its operation caused not only serious in- , convenience to the public but also a large loss in reve- . nue. > “At an average value of 2s a minute for calls over this , route, the loos In revenue ' due to a failure for one hour -Is about £2400,” said Mr i Cassey.