In my wage slave days I used to work as an outside broadcast engineer for a world famous broadcasting corporation based in Britain. An upstart satellite company used to pitch up at sport events and ask for a feed of the core coverage and 'black and burst', a video timing reference signal which as its name implies consisted of sync pulses, a colour burst and black. Plug it in to a monitor and you got a black screen. We gave him a couple of video leads with the signals and off he went.
Just as we went on air he came into our truck and reported "There's pictures on the reference wire and nuffink on the pictures one".
True story, it happened to me. Not a mate's mate but actually to me.