Ferrite Usage in Amateur Radio – All You Need To Know

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The application and history of ferrites is known for centuries now. Ferrites are defined as ceramic materials, which are usually dark grey or black in color. They are generally hard and fragile by nature.

What Are Ferrites, and What are they made up of?

You can understand ferrites as magnetic materials composed of oxides containing ferric ions as the primary constituent. These are classified as magnetic materials because of their ability to exhibit ferrimagnetic behavior.

A ferrite is made up of iron oxide, which is combined chemically with one or even more additional metallic elements. It is formed by the reaction of ferric oxide with any other metal, which can include aluminum, barium, copper, nickel, cobalt, or even iron itself.

What is a Ferrite Used for?

A ferrite serves two primary purposes – inductive and electromagnetic interference (EMI) suppression.

Ferrite as an Inductor

Ferrites constitute one of the core materials used in inductors and transformers. It is majorly used to offer an increase in the permeability of the medium around the coil to augment the inductance. These are widely used within inductor technology to improve the inductor’s performance.

Ferrite as a Resistor

A ferrite is also used to repress or get rid of the RF that you don’t want. There exist two reasons for the same. Fundamentally, you need to keep the RF away from something it shouldn’t get into, and secondly, you must keep the RF inside of something it shouldn’t move out of.

Since this is one of the major problems when it comes to ham radios, it is always recommended to have ferrites around.

How does a Ham Radio make use of a Ferrite?

The type of ferrite that ham uses is soft ferrite. Since their magnetization can switch direction easily and without much loss, there are known as soft ferrites. Among the essential ham radio applications of ferrite is a radio frequency choke (RFC).

This can help to block RF current on feed lines and another station wiring. Ferrite chokes are primarily used on feed lines in antenna and control, audio and computer system cables in your amateur station.

Placed at the transition between an antenna and feed line, a ferrite choke is commonly known as a choke balun. It is exclusively designed to break the antenna from the feed line.

To understand it in a facile way, when the feed line is a coaxial cable, you don’t require it to be part of the antenna. This is because you want to deliver all the power to the radiator i.e., the antenna. A choke balun or a ferrite choke can do this task easily.

To Sum Up

Putting everything together, a ferrite is indeed an amazing material. It is capable of exhibiting all sorts of different properties across a wide frequency range. You cannot only use it as an inductor or a transformer but can also use it as an RF sponge to help keep RF in places where it should be and out of places that it shouldn’t be in.


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