Continued   

     Many LC Filter designs that involve extremely sharp cut-offs cannot be synthesized. With this in mind, Allen Avionics utilizes a special computer aided design program that transforms this type of filter into a flat delay device. Bu utilizing the proper delay sections, it is practical in many cases to achieve a delay flatness of 3% of the nominal delay over the passband. A group of these very unusual Sharp Cut-off Lowpass Delay Equalized Filters are offered by Allen Avionics as Custom Built Lowpass filters detailed elsewhere on these pages. These filters have never been tabulated by anyone before and their excellent specifications make them very desireable for use as Anti-Aliasing filters in D/A or A/D digital systems.

     Four shape factors are offered in this series. Each one is designed to offer the best in cut-off and delay flatness. 

After learning about the different types of filters, you have to know the important information that has to be specified when you order a custom filter. Allen Avionics provides an easy to use, step by step filter order specification form with our catalog and here on our web site that will guide you in the design of a custom filter. The form covers all the filter types and allows you to match your needs with our products. All the parameters like cut-off, shape factor, impedance, size and termination type are easily defined. If your requirements cannot be met with the order form and the standard filter tabulations on our catalog and web pages, our technical sales staff is ready to assist you.