Tunable coaxial filter, preferably for filtering high-power television and VHF signals

摘要

The invention relates to a tunable coaxial filter, preferably for filtering high-power television and VHF signals, which consists of a coaxial supply line which is short-circuited at one end and whose length is less than a quarter of a wavelength. The supply line is connected in parallel to a main supply line which passes on the signal to be filtered, so that its external sheath is connected to the external sheath of the main supply line and its inner core is connected via a capacitor to the inner core of the main supply line, the inner core of the coaxial supply line consisting of two sections of different diameter, of which the section having the smaller diameter is arranged on the side of the short-circuiting element. The idea of the invention is for the outer sheath of the supply line to be split at right-angles to the axis, the short-circuiting element to be attached to the outer sheath and to the inner core over the complete circumference by means of a metallic connection, and the sections of the inner core of the supply line to be connected to one another via a sliding contact.