The following web page shows several photos of vacuum tubes that glow
because they’re either gassy or induce florescence in the their glass
bulbs. Although the English is a little choppy, the narrative and
pictures are informative:

http://www.jacmusic.com/html/article...w/blueglow.htm

The author claims he’s revived gassy tubes by re-heating the getters.
Has anyone tried this?

-Dave Drumheller, K3WQ

On Wed, 25 Jun 2008 16:12:35 -0700 (PDT) wrote:

The following web page shows several photos of vacuum tubes that glow
because they’re either gassy or induce florescence in the their glass
bulbs. Although the English is a little choppy, the narrative and
pictures are informative:

http://www.jacmusic.com/html/article...w/blueglow.htm

The author claims he’s revived gassy tubes by re-heating the getters.
Has anyone tried this?

I was lucky enough to get a tour of Richardson Electronics (outside of
Chicago) a few years ago, and asked their tube people about this. The
answer I got was an immediate NO.

Apparently, if the getter is properly zapped in manufacturing, there
is no Barium left in the getter loop. It's always possible that some
tubes didn't get properly zapped, but this should be a long shot.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

On Jun 25, 7:12*pm, wrote:
The following web page shows several photos of vacuum tubes that glow
because they’re either gassy or induce florescence in the their glass
bulbs. *Although the English is a little choppy, the narrative and
pictures are informative:

* *http://www.jacmusic.com/html/article...w/blueglow.htm

The author claims he’s revived gassy tubes by re-heating the getters.
Has anyone tried this?

-Dave Drumheller, K3WQ

Sounds like hog wash. No blue or blue in tubes is probably normal.
Magenta is probably gas.

"BH" wrote in message
...
On Jun 25, 7:12 pm, wrote:
The following web page shows several photos of vacuum
tubes that glow
because they’re either gassy or induce florescence in the
their glass
bulbs. Although the English is a little choppy, the
narrative and
pictures are informative:

http://www.jacmusic.com/html/article...w/blueglow.htm

The author claims he’s revived gassy tubes by re-heating
the getters.
Has anyone tried this?

-Dave Drumheller, K3WQ

Sounds like hog wash. No blue or blue in tubes is probably
normal.
Magenta is probably gas.

Its very common to see a blue glow on the envelope when
there is fairly high voltage on the tube. I've forgotten the
mechanism but its not gas. Gas can cause a glow between
elements.
AFAIK, there is no way to re-flash the getter.


--
---
Richard Knoppow
Los Angeles, CA, USA

On Jun 26, 4:58*pm, "Richard Knoppow" wrote:
"BH" wrote in message

...
On Jun 25, 7:12 pm, wrote:

The following web page shows several photos of vacuum
tubes that glow
because they’re either gassy or induce florescence in the
their glass
bulbs. Although the English is a little choppy, the
narrative and
pictures are informative:

http://www.jacmusic.com/html/article...w/blueglow.htm

The author claims he’s revived gassy tubes by re-heating
the getters.
Has anyone tried this?

-Dave Drumheller, K3WQ

Sounds like hog wash. No blue or blue in tubes is probably
normal.
Magenta is probably gas.

* * *Its very common to see a blue glow on the envelope when
there is fairly high voltage on the tube. I've forgotten the
mechanism but its not gas. Gas can cause a glow between
elements.
* * *AFAIK, there is no way to re-flash the getter.

--
---
Richard Knoppow
Los Angeles, CA, USA




Usually take as the tube has gone soft , slight air leak over the
years ? soft vlave = soft vac , slight residual gas .. so assume
'gone' soft taken as loss of vac ?.. or may be impurity's in the
metal have boiled out due to over heating ?

G ..

On Jun 26, 1:58*pm, "Richard Knoppow" wrote:
"BH" wrote in message

...
On Jun 25, 7:12 pm, wrote:

The following web page shows several photos of vacuum
tubes that glow
because they’re either gassy or induce florescence in the
their glass
bulbs. Although the English is a little choppy, the
narrative and
pictures are informative:

http://www.jacmusic.com/html/article...w/blueglow.htm

The author claims he’s revived gassy tubes by re-heating
the getters.
Has anyone tried this?

-Dave Drumheller, K3WQ

Sounds like hog wash. No blue or blue in tubes is probably
normal.
Magenta is probably gas.

* * *Its very common to see a blue glow on the envelope when
there is fairly high voltage on the tube. I've forgotten the
mechanism but its not gas. Gas can cause a glow between
elements.
* * *AFAIK, there is no way to re-flash the getter.

--
---
Richard Knoppow
Los Angeles, CA, USA


Two comments.
1) I do recall certain 807s in the intermediate stages of a WWII
transmitter that exhibited blue fluorescence of the glass envelope due
in IMO to electrons missing the plate/anode and striking the glass.
Say this because one could see a definite pattern of the electrode
structure in the fluorescence of the glass, rather like sunlight
shining through a patterned window onto a wall or floor. It was not
just a 'fuzzy' indistinct glow! These 807s were fine and worked
perfectly as drivers and modulators to the final/PA.
A 'soft' or 'gassy' tube on the other hand would have a glow inside
its electrode structure; rather similar to a gas voltage regulator
tube; such as an OD3 VR150 etc.
2) It MIGHT be possible to get rid of gas in a tube by reheating the
getter; there might be active 'getting' material left? No expert on
tube manufacture but understand those getters were heated by RF. So
could be done again?
Whether the gas has leaked in over the years or is residual gas from
original rushed manufacture during say war time conditions might also
be a factor? If air leaks into the tube albeit slowly over many years
it may continue to do so? Although using the tube (i.e. hot) may
discourage (slow down) or encourage (hasten) that?
002 from here.
Newfoundland; where in Dec. 1901 Marconi received the first
Transatlantic wireless telegraph message!

terry wrote:

2) It MIGHT be possible to get rid of gas in a tube by reheating the
getter; there might be active 'getting' material left? No expert on
tube manufacture but understand those getters were heated by RF. So
could be done again?

You can heat them again, but it will be to no good purpose. The getter
is a tray filled with a getter metal, such as barium. The tray is usually
in the shape of a loop so that it is easy to induce RF current into the loop
and heat it very hot. The metal all evaporates and deposits on the cool
glass (usually) It is very unlikely that there is anything left over.

-Chuck

Chuck Harris wrote:
terry wrote:

2) It MIGHT be possible to get rid of gas in a tube by reheating the
getter; there might be active 'getting' material left? No expert on
tube manufacture but understand those getters were heated by RF. So
could be done again?

You can heat them again, but it will be to no good purpose. The getter
is a tray filled with a getter metal, such as barium. The tray is usually
in the shape of a loop so that it is easy to induce RF current into the loop
and heat it very hot. The metal all evaporates and deposits on the cool
glass (usually) It is very unlikely that there is anything left over.

-Chuck

Several years ago a friend gave me several 304TLs. He didnt want them
because they were gassy(glowed blue). This was about 1971. Two of the
tubes still work fine used in a stereo amp, a couple more I gave to a
friend building a modulator the others still sit on the shelf in case
i ever need spares.

Jimmie

wrote:


Several years ago a friend gave me several 304TLs. He didnt want them
because they were gassy(glowed blue). This was about 1971. Two of the
tubes still work fine used in a stereo amp, a couple more I gave to a
friend building a modulator the others still sit on the shelf in case
i ever need spares.

Jimmie

A nice cobalt blue glow isn't gas, but rather is caused by electrons
hitting a slightly fluorescent glass. Some tubes have areas in the
plate that can leak out electrons from the cathode. They will glow
blue from the very start.

Usually, a gassy tube will glow pinkish, and the glow will be situated
inside of the volume surrounded by the plate.

-Chuck

On Jun 26, 7:22*pm, Chuck Harris wrote:
terry wrote:
2) It MIGHT be possible to get rid of gas in a tube by reheating the
getter; there might be active 'getting' material left? No expert on
tube manufacture but understand those getters were heated by RF. So
could be done again?

You can heat them again, but it will be to no good purpose. *The getter
is a tray filled with a getter metal, such as barium. *The tray is usually
in the shape of a loop so that it is easy to induce RF current into the loop
and heat it very hot. *The metal all evaporates and deposits on the cool
glass (usually) *It is very unlikely that there is anything left over.

-Chuck

Chuck: Yes that's logical and I would defer to your knowledge of tube
manaufacture. That's why it was worded 'MIGHT' be possible.
Thanks for the comment additional info.
Terry