On Tue 01 Nov 2022 at 06:49:09 (+0100), to...@tuxteam.de wrote: > On Mon, Oct 31, 2022 at 06:32:17PM -0400, gene heskett wrote: > > [...] > > > I think, but don't know for sure, that they were also helium filled drives, > > a guaranteed disaster. > > > > They used the helium to make the heads fly lower, and when the helium leaked > > out, and air leaked in, > > Possible. > > > the heads flew too high to read the disk. I don't know where Seagate > > recruited the engineers who thought > > up that idea, > > > > Whatever, even I with an 8th grade diploma, knows you cannot keep helium > > anyplace for very long. Put it in a monel metal > > bottle with walls an inch thick and its molecules's are so small that 10% of > > it is gone in 6 or 7 hours.
So the He cylinders that we used after a few months in storage really contained nothing at all! > And these > > jerks thought they could seal it up in a drive housing 1/16" thick? The operative word is seal, not the thickness of the monel walls. Seal—and no cracks. > This is only a half-truth. You know what goes out faster than helium? > Vacuum. And there was a whole glorious epoch in electronics which did > rely on keeping vacuum "in". You should have some fond memories of > that. To be fair, most vacuum tubes aren't bathed in helium, but air, and then only at a one atmosphere differential pressure. A gas cylinder might be as high as 500 atmospheres. And vacuum tubes do contain a getter to deal with outgassing, which will help mitigate slight leaks. Cheers, David.
