A TV broadcast system uses multiplexed and duplex, communication and verification methods, it directs and controls form a central continuity studio one or more remote stand alone TV transmitters to change and/or modify the content of their local broadcast material. Thus it is possible to direct the local broadcast to switch between the general broadcast program or a previously stored (at the remote site) live video. Moreover it is possible to superimpose on the video being broadcast, alphanumeric character and/or image data, which are also previously stored at the remote site.