[Amps] Ionized Gas in the Tube

[Bill Turner]

On Mon, 20 Oct 2003 17:55:08 -0700, "Pat Barthelow"
<aa6eg at hotmail.com> wrote:

>Is the location of the glow important?   I used to see Blue glow on the 
>inside glass of 4-400A amps, and was once told that this is normal, and not 
>indicative of Gas in the tubes.  It was some kind of interaction of high 
>velocity electrons with the glass.  (kind of like Cherenkov Radiation?)  Gas 
>glows have to occur in between the cathode and the plate.....Is that 
>correct?

_________________________________________________________

Correct.  Location is important.  Blue glow on the inside of the glass
is a mild X-ray effect, common even in some receiving tubes such as TV
sweep tubes.  

As you surmised, a glow in between the elements is bad news.

-- 
Bill, W7TI