Quarterwave choke for a microwave oven quartz lamp

A microwave oven comprising:

• a microwave oven having a microwave oven cavity in which microwaves are present at cooking power, the cavity having at least one wall;
• a quartz lamp mounted in said microwave oven cavity, the lamp including a quartz tube, a resistance element mounted in the quartz tube and two power leads connected to said resistance element, at least one of said power leads connected through said at least one cavity wall;
• a quarterwave choke mounted about said at least one power lead and further mounted in the interior of said microwave oven cavity on said at least one cavity wall at the point the power lead exits from said microwave oven cavity;
• said quarterwave choke comprising:
• a metallic outer cylinder;
• a metallic plug having a central aperture mounted in one end of said outer cylinder leaving the other end open;
• a hollow metallic inner cylinder mounted on said plug and extending through said outer cylinder to its open end about the central axis of said outer cylinder;
• means for grounding said outer cylinder, said inner cylinder and said plug to said microwave oven cavity;
• a conductor means mounted interior said inner cylinder and extending through the central aperture of said plug;
• said conductor means connected on one end to a power lead and on the other to said resistance heating element;
• the gap between the outside diameter of said conductor and the inside diameter of said metallic inner cylinder being less than or equal to 0.020 inches;
• sheath means for electrically insulating said conductor means from said inner cylinder and said plug;
• the distance between the open end of said outer cylinder and said metallic plug being substantially equal to a quarter of the wavelength of the microwave energy which may be present in said cavity.