[Amps] "Tubes 201" - How Vacuum Tubes Really Work

[Tom W8JI]

Will wrote:

<It's impossible to run one temperature on zirconium.

 I guess Eimac is lucky they quit making 3-500Z's, since the 
gray power on the anode is the getter and it is zirconium.


>By the way, Terman on page 187 of my Third edition warns
>about excessive resistance in grid leads. Terman states, "
>If the resistance in the grid circuit is high enough, this
>process can become cumulative, resulting in the control 
>grid
>potential suddenly becoming positive and causing the
>**destruction** of the tube as a result of excessive plate
>current."

Will wrote:
<<Nowhere in the whole paragraph about gassy tubes (Effect 
of Gas upon Tube Characteristics) which is under part 13, 
page 316 in this book, says a grid became positive! It only 
says this can cause a grid to become "less negative"!>>

The text of the page in the third editon  of Terman is at 
the bottom of: 
http://www.w8ji.com/fusing_and_floating_grids.htm

Anyone who wants can look and see what it says for 
themselves.

73 Tom