ULTIMATE MINIMUM

Evening Star, Issue 22442, 12 September 1936, Page 4

ULTIMATE MINIMUM

VEST-POCKET TRANSMITTER In the old crystal-set days we were all familiar with the ingenious receivers which fitted inside matchboxes. Now, apparently, it is the turn of transmitters to reach the ultimate minimum. A waistcoat-pocket transmitter, designed primarily for programme work in. crowds and large assemblies in which tho announcer must be able to move quickly to any given point, has been •perfected by the engineering department of the National Broadcasting Company of America. It weighs less than one pound, and, being contained—apart from its two lOin aerial rods—within a 3in cube, is easily grasped in the palm of one’s hand. Current is fed to the midget set by a battery of 90 volts. Tests just completed show that, with a power of one-fifth of a-watt, it can reach a distance of four miles. In actual use its range will be voluntarily limited, tho portable transmitter being intended not to reach listeners directly, but rather to extend the “ pick-up ” scope of tho networks. Ultra-short wave propagation tests have been going on for nearly two years from the tops of New York skyscrapers, and the results secured pointed the way to this new transmitting apparatus. Small as it is, the waistcoat pocket transmitter leaves the radio engineer’s dream yet unfulfilled.