A Coaxial Filter for Vestigial-Sideband Transmission in Television

The problem of building a filter of ladder or lattice type wherein the elements are replaced by coaxial lines is shown to be largely one of geometrical arrangement. A method of designing and constructing such filters is described. Using this procedure, an experimental filter of the ladder type has been built for the television channel of 66 to 72 megacycles. The cutoff sharpness at the lower edge of its frequency range is 32 decibels per per cent of frequency change. This can be achieved with a very compact filter structure. The general performance and range of usefulness of this fiter type in television channels is discussed.