--- In ham_amplifiers@..., R L Measures <r@...> wrote:
On Sep 24, 2006, at 8:40 AM, Bill Turner wrote:
ORIGINAL MESSAGE:
On Sun, 24 Sep 2006 12:05:38 -0000, "pentalab" <jim.thomson@...>
wrote:
### Are u talking about 3-500Z's and 4-1000's ???? [glass
tubes] I have had new 4-1000's that glowed blue. It was
not gas either.... it was an anomoly/defect in the glass....per
Eimac. The glass would glow blue.... only when drive applied.
------------ REPLY FOLLOWS ------------
I don't think this is a defect. Many tubes show a fluorescence on
the
inside of the glass when operating. I was told it was "soft" x-
rays
caused by electrons impacting the anode and then striking the
glass.
I have seen this on 807s running at 750v with this glow on Tx. Soft
I've seen this in sweep tubes also many times. The glass had a blue
glow in places where there were holes open in the anode. I think Rich
is correct on this that some electrons escape, and strike the glass.
However, if the electron is out there at the glass, how does it get
replaced back into the cathode?
X-rays are more like >10,000v.
As I see it, the effect is caused by electrons from the cathode
missing the anode, striking the glass, and bumping electrons in the
fluxing agent up an a higher orbit When the electrons slow down they
fall back to their normal orbit and emit visible photons.
Whether that is the real cause or not, I've seen it many times.
Nothing to worry about.
The tubes that do not fluoresce probably have a different mix of
compounds or elements in the glass.
Agreed. There are several different fluxing agents used in glass
recipes.
This should not be confused with a blue glow between the elements.
That is gas and is something to worry about.
What's to worry about?, it's done.
Bill, W6WRT
Yahoo! Groups Links
R L MEASURES, AG6K. 805-386-3734
r@...
Best,
Will
