There's an old bunker right up the street here that was part of a pretty extensive underground base connecting a bunch of coastal gun batteries to something or other in the harbor [but that tunnel collapsed most of the way in the early 1970s, but there was still an armored door somewhere down there which has since been paved over or otherwise hidden. Anyhow, the base was supplied with enough spares and ammunition to run indefinitely for years, or at least months... ammo runs out awfully fast when you need it... but yeah, back on topic... their sort of primitive communications center is chockablocka full of super neat analogue thingers and doodads, and there's a whole VAULT filled with hundreds of various spare vacuum tubes. I got to meet the guy there who is rebuilding it all to get it running again. The main problem was how they chopped through all the wiring when the base was decommissioned, but they did such a good job keeping them all organised that he says it's pretty straightforward hooking it back up again and he's almost done with that part. The teletype machines all work just fine, too! But holy hell it gets HOT in there when the machines are fired up! Tubular, man.