Amplifies Current Ten Thousand Million Million Times (Jan, 1932)
Amplifies Current Ten Thousand Million Million Times
QUADRILLIONS do not mean much to the reader, even though he remembers the meaning of the term, expressed by seventeen figures in a row. However, a quadrillion is about the number of drops of water in a cubic mile.
With this introduction, it may be said that the screen-grid tube, pictured on an amplifier box in the center of the picture at the left, is used to amplify an electric current ten quadrillion times. When the rod shown in the picture was rubbed with a piece of paper, the electric charge thus produced was enough to stimulate the grid of the tube at a distance up to fifteen feet; and thus turn on and off an incandescent lamp, drawing 100 milliamperes of current from the Thyratron tube on the box at the right, which was controlled by the low-grid-current tube.
The low-grid current tube is a special type of screen-grid tube, in some ways like those used in radio sets.