NEW DEVELOPMENTS

Southland Times, Issue 21997, 22 April 1933, Page 11

NEW DEVELOPMENTS

PROGRESS OF WIRELESS. London, April 10. So many astonishing wireless developments have occurred in the last few months that the technical journals complain of a difficulty in keeping abreast of them. The discovery of a quiescent pushpull enabling an output from battery sets equal to that obtained from electric sets, recently hailed as revolutionary, is already superseded by the invention of a “Class B” valve, costing 14/-, which, with a 120-volts battery current, gives fully two watts of undistorted output, sufficient to fill a concert hall, whereas even the largest sets operated from electric mains are capable of only 1| watt. The new valve, despite its power, uses less current than ordinary valves. New ferrocart coils, with a coil of finely divided iron, give astonishing selectivity equal to the superheterodyne. Another important development is the Westector rectifier, composed of discs treated with copper, enabling fine selectivity, combined with considerable distortionless amplification. Experts consider that combination of these three developments will make existing sets obsolete.