Filter Circuits

Because of the inconsistency of data, and the difficulty of applying same to the practical problems confronting Radio Engineers and Amateurs in the building and selection of parts to form a consistant and effective filter, these data were formulated. It is the aim of the author to present all facts involved in the calculation and construction of filter circuits in a clear and concise way, and, so far as possible, in a non-technical way in order that those without technical training may follow it intelligently. This work is primarily intended to answer the question, "With what facts shall I start, and how shall I build a filter to serve my purpose?" It is designed to get at the underlying principals involved.

The author does not attempt to go into the field of application of filters to telephone work, for there it becomes very complicated and involved. The data given herein is applied only to radio work where smooth direct current is required from an alternating source.

The mathematics of these circuits may be applied to circuits of any magnitude so long as the voltage applied to the apparatus is reguarded, and the parts selected accordingly.