Radar Basics

Tetrode

anode

screen
grid

cathode

control
grid

filament

Figure 1: Tetrode, circuit symbol

anode

screen
grid

cathode

control
grid

filament

Figure 1: Tetrode, circuit symbol

Tetrode

A tetrode is an electron tube with four electrodes. It contains an additional screen grid with a positive DC voltage to shield the control electrode from the anode.

Tetrodes were used as amplifier tubes or as power oscillators.

Picture gallery of Tetrode

Figure 2: Tetrode 5D21 from Western Electronic

Figure 3: Tetrode 6E6P from the IF amplifier of the Russian radar P-12 “Spoon Rest”