I often wondered why the Russian military were big time into valve tube technology. They made millions off them, and each type was built with tank like quality! But why ?? A nuclear explosion causes a massive spike of RF energy, which induces huge voltages and currents in unprotected electronic systems (first seen during the Bikini atoll hydrogen bomb tests, when the electric power supplies in far away Hawaii started going bonkers). This pulse is enough to fry most semiconductor components in these circuits. So that's why valve tubes were favoured over the West's far more modem military transistor technology. Today these valves are highly sort after by audio enthusiasts world wide for their high build quality and sonic performance that transistors can never produce. I guess you could say that they were designed for all the wrong reasons but ended up being used for all the right ones!