Given the physical similarity to the C1150, The C1111 appears to be a pulse tetrode modulator amplifier. The bell shaped anode and funnel structure of the grid support point to high voltage and high peak currents as does the ceramic insulation.

Stig Comstedt has supplied the information that the C1111 & C1150 were used as pulse modulators for Radar magnetrons. He encountered them in the 1960's when serving in the merchant marine.

The wide glass tube envelope is 60 mm in diameter and, excluding the base pins is 130 mm tall.

This exhibit was last updated on 04 April 2009