Abstract: A gas pressure adjusting device in the gas-operated mechanism of a gas-operated autoloading shotgun is in the form of a valve assembly comprising essentially a valve seat encompassing a stepped valve opening consisting of adjacent opening parts of different diameters, a valve body having first and second pressure-receiving surfaces and first and second sliding contact surfaces respectively fitted slideably in the valve opening parts, and a spring urging the valve body toward and into closed state against the valve seat. This valve assembly operates with a double action wherein the gas pressure tapped from the barrel bore acts initially on only the first pressure-receiving surface of the valve body and, upon exceeding a predetermined pressure, moves the valve body past a point where it acts also on the second pressure-receiving surface thereby to be released into the outside air.

Abstract: In the present magnetron operating circuit for generating microwave energy, the circuit components of the filter, the transformer and the rectifier are arranged within a shielded housing, in the same manner as the cathode input portion of a magnetron tube. A feed-through capacitor of the filter is arranged in the low voltage line of the transformer and secured to the wall of the housing to prevent undesired radiation. A coil with a ferrite core of the filter is preferably connected to the filament lead of the magnetron tube.