What the heck does a getter do ?

[bereanbill]

This ? has no bearing on anything...just my pointy head being over-active right now. I understand the fundamentals of how vacuum tubes work..all components except for the getter. Exactly what is it's function...and the "flashing" for that matter. I have heard a few different...and somewhat conflicting I might add...explainations. Can someone clarify this for me ? Thanks in advance..

Update on my first build coming soon. I am abandoning the cascaded preamp volumes in favor of a master volume. I am also adding switchable rectifier settings...ss/tube. Film at 11:00 ...

 

[Colt45]

it gets.

http://en.wikipedia.org/wiki/Getter

 

[bereanbill]

Ok...so what I had heard is correct in the sense that the getter removes impurities within the vacuum. So the chrome-like coating on the inside of the tube...is that the result of the getter reacting with the impurity or is that a component of the getter itself. What I mean is this : does the presence of the chrome-like coating indicate a tube with little use or does it show that impurities were removed from the vacuum. Tubes with a lot of hours seem to have less chrome inside...I have heard this referred to as "getter loss" ??

 

[AudioFreak]

As the getter does it's job it slowly disappears so a full shiny getter should generally indicate a tube with little use and decent vacumn.

 

[bereanbill]

Thanks...that's what I thought...