A video signal input selector is subject to cross coupling between selectable
video
signals. The input selector comprises a video amplifier coupled to amplify a video
signal selected from said selectable video signals. A controllable switch has first
and second elements, the first element receives the selected video and is coupled
to signal ground. The second element receives the selected video and is coupled
to the amplifier. During a first condition the first element is controlled to be
open circuit and the second element is controlled to be short circuit coupling
the selected video signal to the video amplifier. In a second condition the first
element is controlled to short circuit the selected video signal to the signal
ground and the second element is controlled to be open circuit substantially inhibiting
the selected video signal from coupling to the video amplifier.
