If tubes are anything like semiconductors (which I have 20 years experience with) the "differences" have to do with testing and traceability. Military semiconductors come off the same line as the standard devices do, but are subjected to a specified barrage of tests. Commonly referred to as "shake and bake" the military testing weeds out devices that may fail early on. The other significant difference is the paperwork that follows military devices through the factory and test floor, keeping a log of the measured specs as the part goes through the cycle. The parts that pass the military testing are sold under different part numbers and sell for a considerable mark up, anywhere from 10x to 40x the standard device pricing. Just to make things more confusing there are several levels of military screening: 883C, JAN 38510, and Level S (space level, for aircraft and space applications).
Bottom line is they come from the same production line as the chip sitting in your coffeemaker but are tested to insure longevity and consistent quality. Is it worth the premium? They are more rugged so they will last longer, other than that, no.
Bottom line is they come from the same production line as the chip sitting in your coffeemaker but are tested to insure longevity and consistent quality. Is it worth the premium? They are more rugged so they will last longer, other than that, no.