What is Radio Frequency Interference (RFI)

Horace He

Last Updated: August 7, 2023

What is Radio Frequency Interference (RFI)

Radio Frequency Interference (RFI) describes the unwanted noise or disturbance that occurs in radio signals. It occurs when electromagnetic signals, emitted by electronic equipment or other transmitters, interfere with radio signals. This interference can result in buzzing, humming, or audible sounds that disrupt the clarity of the radio signal.

RFI can be caused by various factors. One common cause is the presence of electronic power supplies near the radio. These power supplies emit electromagnetic waves that can interfere with the radio signal. Additionally, natural elements such as solar flares, the electromagnetic disturbance of northern lights, and lightning during a storm can also contribute to RFI, although these sources are not constant and may not be the cause of ongoing interference.

To identify and address RFI, it is important to analyze the interference and its characteristics. This involves determining what is being heard, how often the interference occurs, and other obvious clues. Potential sources of interference, such as nearby electronic equipment or transmitters, should be identified and steps taken to minimize or eliminate their impact on the radio signal.

Frequently Asked Questions

Why Does My Radio Buzz When I Turn on the Lights

Fluorescent lights can cause interference with radios due to the emission of electromagnetic radiation. While this interference is usually not noticeable during normal operation, it may become more pronounced as the lights near the end of their lifespan. However, high-quality lights with effective suppression mechanisms should not cause any interference.

What Is a Good Solution for Dealing With RF Interference

If the RF interference is greater than approximately 20 MHz, one effective solution is to use ferrite clamshells. These clamshells can be easily installed over the cable and are most effective when placed near the receive end.

What Materials Block RF Interference

The materials commonly used for RF shielding include copper, aluminum, nickel silver, pre-tin plated steel, and Mu-metal. Additionally, elastomers and textile fibers can be utilized as RF shielding materials by first making them conductive through the addition of metal fillers and coating.