TALKING TO LONDON

Sun (Auckland), Volume IV, Issue 965, 7 May 1930, Page 7

TALKING TO LONDON

NEW AUSTRALIAN SERVICE HOW MESSAGES WILL TRAVEL Another important link in the growing chain of Empire wireless communication services was forged when the wireless telephone service between Australia and Great Britain was opened for public business. The service will be by far the longest commercial telephone channel In the world, exceeding by several thousand miles the present record circuit, that between Europe and South America. Despite the fact that very remarkable progress in inter-Contin-ental telephony has been made in the last three or four years, it is safe to say that commercial wireless telephony of this kind is by no means so far developed comparatively as wireless telegraphy was when the Empire beam services were inaugurated a few years ago. The experiment in opening the service at this stage is therefore both enterprising and bold. That it will ultimately be satisfactory there can be no doubt, but it appears to he equally certain that in the initial stages there will be inevitable periods of failure and disappointment. These must be expected, and they will have to be accepted until the knowledge gained by practical experience can be added to that obtained by pure laboratory experiment to eliminate initial defects and gradually improve the reliability of service. INTERRUPTIONS Interruption from fading will undoubtedly be a cause of annoyance for some time, and it is probable that the telephone service will he more susceptible to this than the commercial telegraph services are. Although no effective system of eliminating fading has yet been devised, it is possible in a telegraph service to take relatively simple precautions which minimise its effects. Unfortunately these principles are not applicable to a telephone circuit; which is therefore handicapped againsi a circuit designed for telegraphy only. Fading effects will limit the period of communication daily to several hours in the late afternoon and several hours between midnight and daybreak, Australian time. Experience on the beam circuits suggests that these periods will be very elastic. Under very favourable conditions a reasonable service for nearly 20 hours daily might be expected, but when conditions are particularly bad it is probable that on some days communication will be quite impossible. It is unfortunate that the most reliable periods of communication will be outside the ordinary Australian business hours, but it will probably be only a matter of time when the average communication period will be greatly extended. CHEAPER RATES It is interesting to note that the charges for the use of the service will be less than half the initial charges on the Atlantic telephone service opened only three j’ears ago. On that service the initial rate was £5 a minute, with a minimum charge of £ls. The rate on the service to Great Britain will he only £2 a minute, with a minimum charge of £6, despite the fact that the length of the circuit is nearly four times as great as that of the Atlantic circuit. The main reason for this difference is. that the British-Australian service will be conducted on short waves, whereas the first Atlantic service was on a long wave-length. The short wave equipment is far less elaborate and expensive than the long wave equipment, and operating costs are correspondingly lower. Nevertheless, the efficiency of the short wave equipment is far greater than that of the long wave stations, and short wave stations are now being used practically exclusively on the Atlantic service. It will probably be only a matter of months before any subscriber in any of the capital cities of Australia will have access to the service. PATH OF MESSAGES When this is achieved it will be interesting, for instance, to trace the. path of a-call from Hobart to Dublin. It will begin along the Ideal exchange line in Hobart and be communicated to the Hobart trunk exchange. Thence it will traverse a trunk line to the wireless telephone station now being erected to connect Tasmanian subscribers with the mainland. It will be transmitted by wireless telephone across Bass Strait, picked up on the Victorian south coast, and carried by trunk line to the Melbourne trunk exchange. From there it will be carried on another trunk line to Sydney trunk exchange. Incidentally, this trunk line will probably be conveying simultaneously by the “carrier wave’’ system several other telephone conversations and four telegraph messages. From the Sydney trunk exchange the conversation will travel on a short trunk line to the Pennant Hills wireless station, from which it will be sent by wireless telephone to Great Britain. From the receiving post it will he carried on another trunk circuit to the London trunk exchange, and from there impressed on yet another trunk line on which it will pass under the Iris Sea to Dublin. From the trunk exchange there it will pass along yet another circuit to the subscriber’s local exchange, where it will be conveyed to the final circuit, which takes it into his home. In an average case at least a dozen different circuits would be involved and the original word from Hobart would probably be repeated and amplified at least 50 times along various parts of the route until it reached Its destination ear-piece. SERVICE TO NEW ZEALAND

Considerable expansions of Empire telephony may be expected in the next few years. For instance, the way is now clear for the opening of a telephone service between Australia and New Zealand, and this service will be provided as soon as negotiations are completed and the necessary equipment is to hand. It seems not improbable that such a link may ultimately be used to provide telephone communication between New Zealand and Great Britain, as this service could be connected at Sydney with the Anglo-Australian telephone as soon as it is installed, just as Commander Byrd was able recently io speak to New York by telephoning first to Sydney, so that his voice could be repeated at Sydney to New York.