Tubes Asylum Questions about tubes and gear that glows. FAQ

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Tubes Asylum ]

---

[ Alert Moderator ]

---

RE: Metal cased tubes

Posted by TubeAcolyte (D) on March 24, 2014 at 06:39:09

In Reply to: Metal cased tubes posted by FenderLover on March 24, 2014 at 00:19:18:

I found the R-Type site pretty informative because it allows you to at least draw a grainy picture

http://www.r-type.org/static/contents.htm
*UK catkin valves* http://www.r-type.org/addtext/add012.htm
*US metal valves* http://www.r-type.org/articles/art-018.htm

According to what I see here, metal envelope valves were released as a follow up to the older balloon or coke-bottle style valves, mostly as a fact of WW2 needing a better tube (smaller, higher dissipation, better reliability, electrical shielding).

I *think* the metal envelope is more of a stop gap solution until a better glass could be made and a better vacuum could be achieved. The metal tube seems to be glass base formed and sealed into a metal envelope. There's no glass beyond the pin-base to tie-in and anchor the internals (may have acted like insulation).

My question it... knowing what we know of making glass tubes... How do you evacuate the metal can? *brain explodes*

And one hopes that the metal never goes live! *heart explodes*
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
May your tubes be lively, warm, and long-lasting. Holy be thy heater.

This post is made possible by the generous support of people like you and our sponsors:

Signature Sound

[ Signature Sound Lounge ]

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---