GE 2B23 magnetically controlled diode

This valve measures 81x32mm overall and has an octal base

This is a high vacuum diode designed to make use of a magnetic field, supplied by an external soleniod, to control the anode current. The action is the same as in a magnetron, where as the magnetic field is increased the electron stream spirals until it no longer reaches the anode, at which point the valve cuts off sharply.

In Physical Review, V81, No. 2, Jan 15, 1951, the paper "Fine structure of the hydrogen atom. Part II" where it was employed in a circuit to stabilise the current applied to a magnetic coil.

In Physical Review, V91, No. 6, Sept 15, 1953, the paper "Molecular beam investigation of rotational transitions. I. The rotational levels of KCI and their hyperfine structure" it is referred to as a cylindrical magnetron diode. In the apparatus the 2B23 was used operating in the cutoff region to control the frequency of a klystron. An error signal, generated by the beat frequency between a crystal source and the klystron output was fed to the magnetic solenoid round the 2B23, the diode output then controlling the repeller of the klystron.