A Ham’s Guide to RFI, Ferrites, Baluns, and Audio Interfacing is an interesting tutorial on understanding and solving RF interference problems. To solve interference problems, we must understand them. The document describes many EMC issues well. Almost all RFI problems we describe as “RF in the shack” have pin 1 problems as their root cause!
Ferrites can be a very effective tool for eliminating RF interference between systems. To use them effectively, you need understand them. The document gives you the basic information you need on ferrites and gives many practical application examples for using them.