Abstract: A pulse radar apparatus has video quantizing means for digitally encoding the received video signals at a first clock rate. The encoded video is fed into storage means, read out at a second clock rate, converted to analogue form and applied to a cathode ray tube to give a display, e.g. a P.P.I. display. The cathode ray tube has a constant time base speed and different range scales for the display are obtained by switching the speeds of writing into and/or reading out of the store. Multiple stores permit asynchronous reading and writing. Multi-level amplitude coding of the video amplitude is employed.