NotTaR of Television Sets : Wiring transmitted interference         
 Copyright © 1994-2007, Samuel M. Goldwasser. All Rights Reserved. Reproduction of this document in whole or in part is permitted if both of the following conditions are satisfied: 1. This notice is included in its entirety at the beginning. 2. There is no charge except to cover the costs of copying. I may be contacted via the Sci.Electronics.Repair FAQ (www.repairfaq.org) Email Links Page.

  << General erratic behavior |  Index  | Jittering or flickering d.. >>

Wiring transmitted interference

The power that comes from the wall outlet is supposed to be a nice sinusoid at 60 Hz (in the U.S.) and it probably is coming out of the power plant. However, equipment using electric motors (e.g., vacuum cleaners), fluorescent lamps, lamp dimmers or motor speed controls (shop tools), and other high power devices, may result in a variety of effects.

While TVs normally include some line filtering, the noise immunity varies. Therefore, if the waveform is distorted enough, some effects may show up even on a high quality TV.

Symptoms will usually be one or two areas of noise moving slowly up the screen.

The source is probably local - in your house and probably on the same branch circuit - but could also be several miles away.

 <<General erratic behavior | ToC | Jittering or flickering d..>>