Potential storage tube
A potential storage tube is a cathode ray tube for analog storage of the amplitudes of electrical signals. They were used in the interference protection system of historical Soviet radars .
An entire deflection period was stored in the potential storage tube for inter-period compensation . In an elaborately focused electron beam system, a deflection period was stored in a spiral on a cesium layer. Each point on the spiral corresponded to a unit of distance. In the next deflection period, this unit of distance was written to the same point again. If this point already had a charge, this was registered in the tube's anode current, which is therefore lower. The output signal of this tube was then the difference signal between the current and the previous deflection period.
In the Russian radar device P-18 , two of these tubes were connected in series to improve the suppression factor. Both tubes were used in multiplex operation and could therefore be used in the close range to suppress fixed target echoes and in the far range to suppress non-synchronous impulse interference (e.g. transmission impulses from external radar devices that were working on the same frequency).