The hexode is an electron tube with six electrodes: a cathode, an anode, and four grids.

A hexod is an electron tube with six electrodes: a cathode, an anode and four grids.

The appearance of the fourth grid in the lamp was caused by the fact that in pentodes with a separate output of the third (antidynatronic) grid, in the case of using it as a double-controlled lamp, this third grid ceased to perform its main function - to prevent the occurrence of secondary electrons.

Therefore, in the new six electrode lamps, called hexodes, the third grid from the cathode was used for dual control of the anode current, and the additional fourth, closest to the anode, became antidynamic. The introduction of the fourth grid did not give any other additional benefits, and the electrical characteristics of the hexodes differed little from the characteristics of the pentodes.

And since in those years when the hexodes appeared, the schemes with dual lamp control in the radio receiving and transmitting equipment had very limited application, and the demand for hexodes turned out to be insignificant. As a result, for all the years of development and improvement of lamp technology around the world, only a few types of “clean” (that is, not combined) lamps with four grids — hexodes — have been developed and produced.

The pre-war German hex-type lamp AN-1 is a four-volt heating series with a slope S = 1.8 mA / V, Ri = 2 mΩ and a passable capacitance of 0.06 pF. All four grids of this hexod have independent independent conclusions.

The “pure” hexodes have not been mastered in mass production by the Russian electronics industry, and from the combined triode-hexodes only a 6I2P lamp can be called. However, among the combined lamps of Western European production, only one type of triode-hexode is mentioned: this is a German nine-pin finger lamp of the ESN-80 type - a complete analogue of the 6И2П lamp.

It is used for special purposes, for example as a mixing lamp in superheterodyne radios.

Symbol hexode.