[R-390] Tube heat and glass to metal seals

[Chuck Ochs]

Yes, this is true. How else can one explain how vacuum tubes that were made
80 years ago still function perfectly.
This is an obvious problem in the  design of vacuum tubes, and was worked
out a long time ago, most likely by the people at Western Electric, but
maybe much earlier. After all, the mechanical characteristics of vacuum
tubes are based on the design for the lightbulb. Suspects like Tom Edison
come to mind.
Chuck N1LNH
----- Original Message ----- 
From: "Kenneth G. Gordon" <kgordon@moscow.com>
To: <R-390@mailman.qth.net>
Sent: Sunday, March 21, 2004 2:00 PM
Subject: [R-390] Tube heat and glass to metal seals


> I was under the (properly informed) impression that the metal used for
tube
> glass to metal seals was specifically chosen because its coefficient of
> expansion was identical to that of glass, so that leakage from this source
> was essentially non-existent.
>
> I have forgotten the trade name of this metal.
>
> Comments from the peanut gallery?
>
> Ken W7EKB
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