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Radio Frequency Interference (RFI)


As our lives become filled with technology, the likelihood of electronic interference increases.  Every lamp dimmer, garage door opener or other new technical “toy” contributes to the electrical noise around us.  Many of these devices also “listen” to that growing noise and may react unpredictably to their electronic neighbors, including Amateur Radio transmitters.

Sooner or later, nearly every active Amateur Radio operator will have a problem with interference.  This could involve interference to a neighbor's equipment, or, more likely, some form of intererence to Amateur Radio from the noisy devices that can sometimes even be found in our own homes.  The good news is that most cases of interference can be cured!  The proper use of “diplomacy” skills to communicate with a neighbor and standard technical cures will usually solve the problem.

RFI: ARRL Laboratory On Television--WATCH!

ARRL's Ed Hare, W1RFI and Mike Gruber, W1MG talk about RFI problems on a Common Point, a Cable Access TV show hosted by Dan Thomas.  Mr. Thomas serves on the Board of Directors of the Vintage Radio and Communications Museum of Connecticut (VRCMCT). Associate Producer: ARRL Assistant Laboratory Manager, Bob Allison, WB1GCM

Links to all other Common Point Shows are available at Simsbury Community Television.  Common Point is a show for and about communications.

Links to other videos include:

Identifying & Locating Power Line Noise, Produced by the ARRL Laboratory, written and directed by Bob Allison, WB1GCM and narrated by Jerry Ramie, KI6LGY

Power Line RFI Investigation in Pleasant Hill, California, Video of an RFI Investigation in Pleasant Hill, California.

About Amateur Radio.  Featuring ARRL Laboratory's Bob Allison, WB1GCM. From Simsbury Community Television's, Common Point, Produced by Dan Thomas, NC1J


What Is It?  While this question may seem intuitive, it may be the wrong one to ask if you have an RFI problem.  By Ed Hare, W1RFI.

Electronic Noise Is Drowning Out the Internet of Things.  Our increasingly connected world needs better protection against RF noise pollution, By Mark A. McHenry, Dennis Roberson & Robert J. Matheson.  IEEE Spectrum, August 18, 2015

Hunting Down RF Noises.  Find noise sources both outside and inside your home with a systematic approach, by Michael Foerster, W0IH.  QST February 2015, p 45.

Locating RF Interference at HF.  A proven and practical approach to dealing with RFI from grow lights and more, by Tom Thompson, W0IVJ.  QST November 2014, p 33.

A Quick Look at Radio Frequency Interference, by Joel R. Hallas, W1ZR.  QST May 2009, p 61.

Interference Primer - Parts 1 and 2 Derived from QST Lab Notes columns.  Contains general information on Radio Frequency Interference.

Web Links

Information for Electric Utilities


Naval Postgraduate School RFI Handbooks

Special thanks to George F. Munsch, W5VPQ for providing these documents.  They contain useful and comprehnsive information for both RFI locating and noise mitigation.  By Wilbur R. Vincent, W6PUX, George F. Munsch, W5VPQ, Richard W. Adler, K6RWA, and Andrew A. Parker, WV1B.