this post was submitted on 27 Aug 2023
171 points (98.9% liked)

Asklemmy

43945 readers
821 users here now

A loosely moderated place to ask open-ended questions

Search asklemmy ๐Ÿ”

If your post meets the following criteria, it's welcome here!

  1. Open-ended question
  2. Not offensive: at this point, we do not have the bandwidth to moderate overtly political discussions. Assume best intent and be excellent to each other.
  3. Not regarding using or support for Lemmy: context, see the list of support communities and tools for finding communities below
  4. Not ad nauseam inducing: please make sure it is a question that would be new to most members
  5. An actual topic of discussion

Looking for support?

Looking for a community?

~Icon~ ~by~ ~@Double_A@discuss.tchncs.de~

founded 5 years ago
MODERATORS
 

The title is a bit over dramatic but, per the title, if you could contribute with one piece of knowledge to a book that every single individual should learn from in order to kickstart a civilization, what would be yours?

My personal choice would be the process of soap making, from scratch.

you are viewing a single comment's thread
view the rest of the comments
[โ€“] qyron@sopuli.xyz 4 points 1 year ago (2 children)

Electronic valves are still a thing?

I had relatives that swore on radios based on that technology could endure the detonation of bomb and still work flawlessly.

And I had a colleague in school that saved up to be able to buy a valve based guitar amplifier.

[โ€“] CanadaPlus@lemmy.sdf.org 2 points 1 year ago

They didn't stop working somehow. The trick is that they need a very high (deadly) bias voltage to work, are mechanically delicate, have to be heated and possibly cleared of gasses leaking in, and from what I can tell have inferior characteristics for a lot of applications.

On the other hand, your relatives are right about the electrical toughness, and they have no firm upper frequency limit, so they still have industrial niches.

[โ€“] mobyduck648@beehaw.org 1 points 1 year ago

Yeah the guitar amp and vintage HiFi markets keep a few types (mostly power triodes and pentodes but also preamp valves and even a couple of rectifiers) in production, largely in the former Eastern Bloc. There's a few people on YouTube making their own too.