Locating Inside Sources
All steps should be performed while interference is active
Go to your main circuit breaker or fuse panel with a battery powered AM radio tuned between stations so all you hear is the offending noise. ( If at night or in an enclosed room, be sure to have a working flashlight. )
If the noise is present and corresponds to the disturbing interference, shut off all power to your premises by turning off the MAIN circuit breaker or equivalent enclosed device. (DO NOT ATTEMPT TO REMOVE CARTRIDGE FUSES or OPERATE EXPOSED or OPEN-TYPE DISCONNECTS IF PHYSICAL CONTACT WITH ELECTRICAL CIRCUITS IS AT ALL POSSIBLE.) If the noise on the AM radio stops while the power is off, the source of the interference is within your own residence.
Restore the main circuit breaker. Don't forget to reset clocks after the interference source is located.
Assuming the noise stopped while the electric was off, you can now locate the circuit supplying the power to the noise source. While monitoring the battery powered AM radio as before with the offending noise present, turn off and on the individual circuit breakers one at a time until the noise stops. Leave off the breaker that stops the noise.
You must now determine what has been turned off by going from room to room, if necessary, checking outlets, appliances, and lights for the absence of electricity. The offending noise will be something on this circuit. Turn the breaker back on and wait for the noise to return.
With the noise back on and using the AM radio to monitor it, return to the area of the noisy circuit and unplug everything on this circuit one at a time until the offending device is found.
Door Bell Transformers
Heating Pads (of all kinds)
Recessed Ceiling Light Fixtures
Furnace Control Circuits
TV Top & Stereo, Amplified Antennas
(*) Causes Radio Interference Only
*Screw In Photocells
Low Energy Compact (screw in) Florescent Lights
*Touch Control Lamps
Clean Air Machines (table top and furnace type)
*Light Dimmer Controls
These devices, when causing interference, are in violation of Federal Communications Commission rules, and regulations and are a nuisance to you and your neighbors. It is important for your own safety to have the offending device repaired or replaced to insure normal safe operation. Most radio and television interference sources are the results of an arc. This arcing will get hot and create a fire hazard. Your interest and assistance are sincerely appreciated.