19-inch vented rack mount 2RU chassis for 12 modular units. Used in surveillance or security type applications. A video camera's baseband video output can be modulated to any cable television channel and combined with existing TV signals to permit any outlet to monitor the camera feeds. Compact chassis can support up to 4 fixed channel or agile modulators and can be mounted in practically any location. High performance modulators easily permits placing camera signals on adjacent channels.