THE COUNTERPOISE EARTH.

Press, Volume LXVIII, Issue 20731, 16 December 1932, Page 27

THE COUNTERPOISE EARTH.

ADVICE BY RADIO ENGINEER. It is a well-known fact that conditions of radio reception vary over even small areas. In many cases poor reception may be duo to tho difficulty of securing a good "earth" connexion for the receiver. Those who, living in a very dry district, experience trouble in this respect, might do well to study the advice of an expert radio engineer, who, writing in "Popular Wireless," savs: — '"I am often asked whether it is better to use an ordinary earth or a counterpoise. This depends a good deal upon particular conditions. An ordinary earth is, as a rule, much simpler to make, and for that reason tho vast majority use this type of earth, those who use the counterpoise type being verv much in the minority. "Tho counterpoise earth involves a certain amount of trouble and it is seldom convenient. At the same time, it is far better to have a good counterpoise than an inefficient earth of the ordinary type. The counterpoise will "•eneraliy have a much lower resistance, since the wholo of the aerial circuit becomes a metal conductor. , "Almost invariably tho majority of the resistance in an ordinary aeriiilcarth circuit occurs in the earth connexion. I do not mean the actual connexion between the set and tho earth lead, but the connexion between tho "earth" itself and the ground. Moreover, it varies according to the state of the ground and the time of the year. "A properly constructed counterpoise earth acts as an earth screen, and in this way it overcomes effects which are sometimes due to variations in the electrical conductivity of the ground beneath tho aerial."