Ham Radio Extra Class Practice Test 2026 - Free Extra Class License Exam Questions and Study Guide

A choke or ferrite core is typically used to reduce electromagnetic interference (EMI) in radio circuits because it acts as a passive component that suppresses high-frequency noise while allowing lower frequency signals to pass through. This is particularly important in radio applications where clarity of the signal is paramount. Ferrite cores are made from materials that have high magnetic permeability, which helps to absorb and dissipate interference rather than letting it propagate through the circuit.

Chokes, often designed as inductors, work on the principle of electromagnetic induction. They oppose changes in current and thus can block or significantly attenuate unwanted high-frequency signals. Ferrite cores, used in conjunction with chokes, can enhance this capability by providing a medium where the magnetic field from the inductance can effectively reduce high-frequency disturbances.

By incorporating these components into a radio circuit, users can achieve cleaner transmissions and receptions, improving overall performance and signal integrity.