DX Engineering Ferrites are partially magnetic metal and ceramic mixes available in a variety of forms, including toroid core, bead type and plastic-covered split-bead ferrite called snap-beads. They are used in a myriad of RF suppression applications to mitigate RFI (radio frequency interference) as well as to reduce pulse and other types of RF noise interference. Special ferrites are used for experimentation and electronic circuit building and for making transformers, RF chokes and antenna baluns.
The variations of magnetic and non-magnetic metals and non-metal ceramics used to make ferrites are called “Mixes” and each has different radio frequency properties or ranges. Therefore, different mix number ferrites are typically used for different applications within those ranges, determined by decades of experiments by engineers and applications by hams. Each Mix has been assigned a color code to help identify the ferrite, so numerical labeling is not used on the metal. Color coded ferrite can be identified long after the numbered package is discarded or has disintegrated with time.
How do they work? Simply use snap-on beads on a cable or wire. An even more effective choke takes a few to several turns of a wire or cable through and around a ferrite snap-on bead or toroid core. This mitigates RFI to, or from, the connected RF noise producing or noise affected electronic device. The results can be very surprising. Solving noise and RFI can be frustrating. Due to the nature of RF and noise interference suppression; the techniques of appropriate use of ferrites can take a bit of trial and error, but are often the best solution for a difficult problem.