RADIO TELEPHONY

Press, Volume LXXI, Issue 21533, 24 July 1935, Page 20

RADIO TELEPHONY

?TALUE IN BACK-COUNTRY COMMUNICATION INSTALLATION AT KAIKOURA Formerly undreamed-of possibilities In back-country communication are opened up by the radio telephone apparatus that has been installed this week for Mr H. C. Acton-Adams, on the Clarence Reserve estate, Kaikoura. Radio waves will in future bridge the 18 miles of mountainous country between the home station and the back station at Quail Flat on which no telephone line could withstand the severity of winter storms. As far as is known this is the first use of radio telephony for regular communication between isolated backcountry stations, and a special permit had to be obtained from a Government which is jealous of any usurpation of the prerogatives of its own efficient and extensive communication systems. Nevertheless, there is much country in New Zealand in which all-the-year-round telephone communication is a virtual impossibility, and it is considered likely that there will be further developments in the system which has been successfully launched this week at Kaikoura. • Low-Power Transmitters The apparatus consists of two lowpower transmitting stations and receivers, and the equipment for each is housed in a small cabinet measuring two feet long by a foot wide and a foot deep. The power supply comes from four 45-volt dry batteries and dry cells, and it is expected that these will not have to be renewed more frequently than once in six months on the basis of not more than two hours' operation each day. These small transmitting. stations have been allotted wave-lengths of 185 and 195 metres respectively—that is, Just below the broadcasting band, and well clear of the bands used by amateur transmitters. The transmitters, therefore, are not operating on what are known as "short waves," and are consequently limited in range. Nevertheless, with an output of only three ■watte—less than a sixteenth of the Eower used in the average lighting ulb—these little transmitters are capable, under good conditions, of a range of 150. miles or more. Simple Operation It is not intended, of course, that the apparatus should be used for any other purpose than the transmission and reception of the signals between the two sets. They are not radio transmitters in the accepted sense, and the operators have been granted a dispensation from the necessity of passing the examination in Morse code Which all amateur operators have to undergo. The apparatus is no more difficult to use than a telephone. The operator uses headphones and speaks into an ordinary telephone mouthpiece, which projects from the panel of the instrument. The only controls are an "on-and-off" switch and a switch for changing over from the transmitter to the receiver, while a meter on the panel registers the aerial output. Messages, of course, have to be exchanged at predetermined hours each day. The designer of the apparatus was Mr Strath McKnight, of the staff of the • Electric and General Import Company, Tricity House, Christchurch, one of the pioneer amateur radio transmitters in New Zealand.