Television interference is the presence of an electromagnetic force that causes one or more components of a television to operate abnormally. The result is a degradation of the image or sound quality of a television broadcast. Extreme cases of television interference can completely stop the proper reception of a signal. Sources of interference can range from natural phenomena such as sunspots to standard household appliances. Objects that generate strong electrical fields also can cause interference.
Electromagnetic fields are generated by many types of objects, both in the home and in the environment. Power lines, radios and even fluorescent lights all generate signals that could cause television interference. In the home, common causes of interference are appliance and other electronics. Even when turned off, some devices still emit a faint signal that could be amplified by other factors and cause a problem.
Television interference sometimes can be caused by the elements of the television itself. Exposed wires and circuit boards on the inside of the set could be acting like antennas for disruptive signals that otherwise would be stopped by proper insulation. The proximity of some electronics to a television also can be the cause of interference.
Environmental factors also can cause interference. The sun regularly emits strong electromagnetic waves that not only cause television interference but also disrupt satellites and other devices. Atmospheric conditions such as tropospheric ducting can cause signals to mingle before reaching the television and lead to degraded image quality. Even the presence of physical barriers such as walls, metal pipes and mountains can affect the quality of a signal.
There are situations in which television interference can be caused by other radio or television stations. A broadcast signal that is too powerful can cause a television to distort the image, because the circuits are unable to mitigate the strength of the waves. Multiple radio stations in highly populated areas can create a kind of congestion in which no one signal is able to move without interacting with another, causing interference on all levels.
Resolving television interference can be difficult. Some common resolutions are to disconnect and unplug other electronic components and appliances that use a lot of power. Checking to see if other people in the area are experiencing interference can indicate that there is a larger problem in the environment. The electrical wires inside of the walls of a home also can be a source of interference, requiring that they be better insulated.