WIRELESS TELEPHONY.

Taranaki Daily News, 3 November 1922, Page 2

WIRELESS TELEPHONY.

U r m 9-DATE PLANT IN HAWERA. During the past few months the study of wireless telephony has made great strides throughout the Dominion, especially in view of the great possibilities of broadcasting. This is very evident in Taranaki, where the high poles and connecting wires that denote the wireless aerial are now becoming conspicuous. In Hawera, very great progress has been made, a Wireless Club having been formed, and demonstrations given from the plant built and erected by Rowson Western Electric, at their premises in Regent Street. The receiving apparatus was built on the Marconi hetrodyne principle, with one stage of amplification in shunt with an audion frequency transformer. The tuning coils were designed by the builders, and in addition to the usual primary and secondary coils, a regenerative coil has been added, which considerably amplifies the set. Condensers of .001 Micro Farad capacity have been inserted in the primary and secondary circuits, making the set extremely sensitive to wave-lengths up to 1000 metres. The valves are of the Marconi pattern, with a 24-volt plate pressure, and 6 volts on the filament, which is controlled by two separate rheostats in the primary circuits. The panel is of santanayo, measuring 3 ft. by 16 in., and is supplied with current from two 24-volt, batteries for the high tension, and one 6-volt for the low tension.

The headphones are of the Brown type, with a total resistance of 3000 ohms, and are inserted in series with the high-tension battery, and the plate of the secondary tube. The serial is built on the 2-wire L type principle, with an overall length of 100 feet, and a total height of 45 feet from the ground. This set is remarkably sensitive, enabling the American and Australian stations to be heard with ease. It might be mentioned here that both telegraphy and telephony may be heard on this set with equal audibility; also that those who have sets capable of picking up the Wellington station, and whose call is VLW, the night wireless signals are sent out as usual on Monday and Thursday evenings, Greenwich date (Tuesday and Friday, New Zealand date). The time signals begin at 21 hours 00 m. 00 s. Greenwich mean t’me. and is repeated at the first, second, fourth and fifth minutes.