What Causes Radio Noise Interference and Annoying Buzzes

Sometimes you might experience interference and annoying radio noise or buzzing while listening on the AM band in particular. The question is, what causes that?

Tip: A very good battery operated portable AM radio is great for preparedness.

Causes of AM Radio Noise Interference

A list from C.Crane, maker of one of the best long-range AM radios

Dimmer switch (even in ceiling fans)Touch lamp (even when turned off)
Fluorescent light bulbsFluorescent tubes
Incandescent bulb that is about to burn outLED light bulb (non-FCC certified types)
Automatic on/off night lightsAutomatic outdoor yard lights
Christmas tree lights & other blinking bulbsFaulty electrical switches
Electronic bug and pest controllersUltrasonic motion detectors
Electric blankets120VAC smoke detectors (battery operated OK)
12VDC invertersSmart-meters from electric company
StreetlightsDirty insulators and transformers on nearby power pole
Nearby televisions or monitorsCable or satellite boxes
Ionic BreezeĀ® or other electrostatic air purifierCPAP machines
Smart speakersCordless phones (2.4GHz)
Appliances with motorsModems and/or routers
Desktop Computer or LaptopTablet or Smartphone
Cell phone chargersSwitching AC adapter

How To Eliminate Radio Noise and Interference

The most obvious solution is to turn off the offending device.

Temporarily switch the radio from AC power to battery power to see if the interference is coming from the electrical outlet. If the noise stops, a Radio Noise Filter/Surge Protector (view on amzn) can dramatically reduce the interference.

Turn off all circuit breakers to see if the noise stops. If it does, then you know it is something in your house. Turn on one circuit at a time to isolate what area the noise is coming from.

Use a battery-operated radio as a direction finder. Turn the radio until the loudest noise is heard. The front and back of the radio will usually point to the noise origin.

Carry a battery-operated radio around the neighborhood paying attention to where the noise may be coming from.

If a power pole is suspected, call the utility company. They will usually check the area. Sometimes it’s from a transformer. I’ve also heard that it may have something to do with the insulators.

I have had the best success finding the source (sources) of AM radio band interference by simply using a small portable AM radio as a direction finder. Tune the radio to a frequency with no station (just noise). Then walk around until it gets louder – until you have pretty much determined where it’s coming from.

One of my biggest sources of interference in my home is the solar power system inverter (48V DC battery bank to 120 VAC house power). If I really want to spend a little time during an evening tuning in distant stations, I’ll just shut it off for awhile.

CCRadio 2E by C.Crane

Here’s a picture of my C.Crane AM Radio:

CCRadio2E for long distance AM radio listening

What a great AM radio! The audio is tuned for the spoken word. Sounds great! The “2E” model is especially good for long distance tuning.

( view on amzn )

[ Read: Best AM Radio for DX Long Range Listening ]

[ Read: Best Cheap Portable Pocket AM/FM Radio ]