A negative filter is a passive device that removes a video signal from entering a non-subscribing cable customer's home. It is the most effective and economical method of pay television security in the world. The filter attenuates the video carrier of the specified channel to a point where there is no viewable picture on the television set. Negative filters are installed at the subscriber outlet of the distribution tap or within lock boxes for multiple dwelling units.

 

See our Single Channel Notch for more details.