NEW PHONE SYSTEM

Hokitika Guardian, 22 June 1928, Page 2

NEW PHONE SYSTEM

CARRIER WAVES

(Bv Telegraph—Per Press Association.)

WELLINGTON, June 21

As one of the of investigations made by the Chief Telegraph Engineer when ho was abroad last year, it is proposed to introduce into New Zealand telephone practice at an early date what is known as “Carrier current” telephony, one of the most remarkable of recent developments in the field of electrical communication. An announcement to this effect was made by the Postmaster-General, Hon. Mr Nosworthy, in an interview.

“Briefly,” said Mr Nosworthy, “the carrier current system consists in the application of radio frequency methods to existing telephone circuits, enabling additional telephone speech channels to be obtained without increasing the wires, which, however, form the guiding path for the highfrequency currents, by the use of which additional speech channels are rendered practicable. The new process is in reality a system of wireless communication, in which the electric waves, instead of being broadcast, are directed along the metallic conductors of the wires already erected, without interfering with the purposes for which such wires were originally designed. By using the electro magnetic energy in this way, much lower power is required in the Case of the well-known radio-telephone broadcasting stations. The most important feature, of the new System, from a practical point ol view, is the large saving that it effects in the installation costs. When it is realised that there is a practical limit to the number of wires that can be placed on a pole line, and that the toll lines involve heavy capital expenditure. as well as recurring annual charges for maintenance, tlie great savings which can be effected by imposing additional communication channels on tho existing circuits will be apprccatod. In addition to effecting a considerable saving in installation and line maintenance costs, the carrier system provides a very satisfactory speaking circuit, and as compared with the well-known metallic wire circuit, gives louder speech, and is less subject to the interfering noises caused by the power lines and similar disturbing influences. Moreover, the carrier system possesses great flexibility, and has a unique application to tlie variety of conditions met with in a young and developing country, .such as New Zealand. After careful consideration of the long distance telephone needs of tho Dominion, and after the preparation of the ultimate scheme is complete, the execution of which will follow as the need arises, it has been decided to procure from the United Kingdom carrier equipment that will increase and greatly improve the toll facilities between Auckland and Hamilton and Palmerston North and their switching districts, and the scheme will also duplicate the arterial toll outlet connecting Christchurch with tlie northern districts of the South Island and with Wellington. Tlie installation of this equipment will not only , relieve tlie congestion which now exists between the places named, blit will also provide a margin of circuits over and above immediate requirements and will, thus tend to promote traffic between points where, under tlie existing conditions, development has in the past been somewhat retarded. It is not expected that the delivering of the whole of the apparatus mentioned will be obtained until next year. It is expected, however, that the initial part of the equipment will reach New Zealand in a few months’ time.”