The Duct Capacitor

This paper describes a new type of feed-through capacitor having outstanding capabilities in the suppression of radio interference, particularly at the higher frequencies. It is shown that the filtering obtained is of the nature of attenuation along a transmission line of high loss and low characteristic impedance. Furthermore, the construction is such that complete shielding can be obtained between the input and output leads. A description is given of a typical duct capacitor; also, two of the principal applications are discussed.