Glow-In-The-Dark CRT? Freaky...

S

Steve Reinis

Guest
I have this lightbox from a Projection TV. It's an RCA PTK195 chassis.
It's a spare that I bought on the cheap and it's been sitting in my closet
for when the day comes I need parts for my working 52" RCA set.

The other night the power went out and I was fumbling around in the closet
grasping for a flashlight. I noticed this very dim green glow in the dark
down on the floor and couldn't figure out what is was until I realized it
was coming from the green CRT in the ligthtbox.

Whoa... Weird... This lightbox has been in the closet, which is pitch
black, for many months now. No power had been applied to it recently, no
exposure to light or anything that would make a CRT emit a soft glow. (at
least, anything that I know of)

It's still glowing two night later!! Albeit, it's extremely dim, you can
see the green CRT glowing by itself! I know a bit about electronics and do
know the basics of how a CRT works, but this puzzles me! The red and blue
CRTs are totally dark and as stated, the set has not been powered up or
exposed to any sources of light.

Three nights now I've noticed it glowing by itself. How is this possible???

-Steve
 
How's this for a guess that's way out there? Maybe it's very very mildly
radioactive?

William
 
Both of those situations I know... Really wanna see a CRT glow? Expose it
to UV "blacklight" and it glows. But this lightbox had been in total
darkness for many months, and not powered up in the same amount of time.

This seems to be glowing withou any external stimulation.


Arthur Jernberg <stubby@comcast.net> wrote in message
news:Qf2cnSja2tSjofyiXTWJjg@comcast.com...
Take any crt and place it at a location that is dark, allow your eyes to
adjust to the dark area. Take a flashlight and place the lens against the
front of the crt, switch the flashlight on for a few seconds, switch the
flashlight off and remove it from the face of the crt. Whoa, the phosphors
of the crt will glow, being activated by the light from the flashlight.
Also after a tele has been on for a while switched it off, darken the
room,
and behold, the phosphors in the crt also will glow a bit. Natural actions
of phosphor luminescient coatings, activated by electron beams, external
ambient light, etc. They all tend to glow after tha activating source is
removed. I'm sure a nice professor can supply a more complete explaination
of the effect, cause, and duration.
"Steve Reinis" <noemail@all.com> wrote in message
news:bjr73c01qs4@enews4.newsguy.com...
I have this lightbox from a Projection TV. It's an RCA PTK195 chassis.
It's a spare that I bought on the cheap and it's been sitting in my
closet
for when the day comes I need parts for my working 52" RCA set.

The other night the power went out and I was fumbling around in the
closet
grasping for a flashlight. I noticed this very dim green glow in the
dark
down on the floor and couldn't figure out what is was until I realized
it
was coming from the green CRT in the ligthtbox.

Whoa... Weird... This lightbox has been in the closet, which is pitch
black, for many months now. No power had been applied to it recently,
no
exposure to light or anything that would make a CRT emit a soft glow.
(at
least, anything that I know of)

It's still glowing two night later!! Albeit, it's extremely dim, you
can
see the green CRT glowing by itself! I know a bit about electronics and
do
know the basics of how a CRT works, but this puzzles me! The red and
blue
CRTs are totally dark and as stated, the set has not been powered up or
exposed to any sources of light.

Three nights now I've noticed it glowing by itself. How is this
possible???

-Steve
Click to expand...
 
The phosphors of any CRT will glow with a bit if UV radiation. Even
though the CRT is in the dark to your eyes, there may be enough UV
radiation from somewhere to make it glow. UV light is actually
invisible to the eyes. If you look directly in to a UV source (bad to
do), you will some blue glow because of the sub harmonics in the UV
source.

Being of phosphorescence, the phosphors on a CRT will easily glow in a
very dark environment. I have a watch with phosphor coated hands. They
glow in the dark for the whole night, and they are not radio active from
what I was told by the manufacture. And, there is no battery in the
watch. It is a windup one.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
==============================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
==============================================
"Steve Reinis" <noemail@all.com> wrote in message
news:bjr73c01qs4@enews4.newsguy.com...
I have this lightbox from a Projection TV. It's an RCA PTK195 chassis.
It's a spare that I bought on the cheap and it's been sitting in my
closet
for when the day comes I need parts for my working 52" RCA set.

The other night the power went out and I was fumbling around in the
closet
grasping for a flashlight. I noticed this very dim green glow in the
dark
down on the floor and couldn't figure out what is was until I realized
it
was coming from the green CRT in the ligthtbox.

Whoa... Weird... This lightbox has been in the closet, which is pitch
black, for many months now. No power had been applied to it recently,
no
exposure to light or anything that would make a CRT emit a soft glow.
(at
least, anything that I know of)

It's still glowing two night later!! Albeit, it's extremely dim, you
can
see the green CRT glowing by itself! I know a bit about electronics and
do
know the basics of how a CRT works, but this puzzles me! The red and
blue
CRTs are totally dark and as stated, the set has not been powered up or
exposed to any sources of light.

Three nights now I've noticed it glowing by itself. How is this
possible???

-Steve
 
"Steve Reinis" <noemail@all.com> wrote in message
news:bjr73c01qs4@enews4.newsguy.com...

it coul d be one of two or more things going on:

Projection CRT phosphors are hit VERY HARD with electrons while they're on.
Now the human eye has a very wide dynamic range, something like a billion to
one.

So if we assume the glow from a working CRT is right up there near your
eye's upper limit,
then even if it had a remaining glow of ONE BILLIONTH that level, you should
be able to see it.

Or there could be some energy stored in the phosphors from all that electron
bombardment.
If the energy is stored in some quantum transition that is very very
unlikely, then that energy will be released over a very long time. Just
like radioactivity,


Three nights now I've noticed it glowing by itself. How is this
possible???

-Steve
Click to expand...
 
On Thu, 11 Sep 2003 22:51:15 -0500, Steve Reinis hath writ:
Both of those situations I know... Really wanna see a CRT glow? Expose it
to UV "blacklight" and it glows. But this lightbox had been in total
darkness for many months, and not powered up in the same amount of time.

This seems to be glowing withou any external stimulation.
Click to expand...
Did you check the basement immediately under the closet for pods?

Jonesy
 
Steve Reinis wrote:

I have this lightbox from a Projection TV. It's an RCA PTK195 chassis.
It's a spare that I bought on the cheap and it's been sitting in my closet
for when the day comes I need parts for my working 52" RCA set.

The other night the power went out and I was fumbling around in the closet
grasping for a flashlight. I noticed this very dim green glow in the dark
down on the floor and couldn't figure out what is was until I realized it
was coming from the green CRT in the ligthtbox.

Whoa... Weird... This lightbox has been in the closet, which is pitch
black, for many months now. No power had been applied to it recently, no
exposure to light or anything that would make a CRT emit a soft glow. (at
least, anything that I know of)

It's still glowing two night later!! Albeit, it's extremely dim, you can
see the green CRT glowing by itself! I know a bit about electronics and do
know the basics of how a CRT works, but this puzzles me! The red and blue
CRTs are totally dark and as stated, the set has not been powered up or
exposed to any sources of light.

Three nights now I've noticed it glowing by itself. How is this possible???

-Steve


Radon?
Click to expand...
 
I kinda thought this may be a good reason for it glowing. After all, those
CRTs are driven very hard when running... It's just amazing how bright they
are!

I guess the green CRT is sensitive or something... I pulled the back off of
my working set with the identical lightbox and it too had a glowing green
CRT! Understand it wasn't bright as a flashlight or anything, but it was
much brighter than the CRT that had been in storage without use.

-Steve

George R. Gonzalez <grg2@comcast.net> wrote in message
news:_Nj8b.324715$cF.98418@rwcrnsc53...
"Steve Reinis" <noemail@all.com> wrote in message
news:bjr73c01qs4@enews4.newsguy.com...

it coul d be one of two or more things going on:

Projection CRT phosphors are hit VERY HARD with electrons while they're
on.
Now the human eye has a very wide dynamic range, something like a billion
to
one.

So if we assume the glow from a working CRT is right up there near your
eye's upper limit,
then even if it had a remaining glow of ONE BILLIONTH that level, you
should
be able to see it.

Or there could be some energy stored in the phosphors from all that
electron
bombardment.
If the energy is stored in some quantum transition that is very very
unlikely, then that energy will be released over a very long time. Just
like radioactivity,


Three nights now I've noticed it glowing by itself. How is this
possible???

-Steve
Click to expand...
 
Re: your phosphor coated watch hands...

I wonder if it's just that the green phosphor is super sensitive... Perhaps
that why most "glow in the dark" items are green? Anyhow, I was so curious
about this that I pulled the lightbox from my working set that had been in
use. It's green CRT was glowing away, too. Much brighter than the CRT in
storage, but not exactly bright enough to really illuminate anything. It
gradually got dimmer, but it glowed brightly (In comparison) for quite some
time. The red and blue CRTs glowed for about two minutes and then died off
to the point I could not see them.

-Steve

Jerry G. <jerryg@total.net> wrote in message
news:bjsft2$f5o$1@news.eusc.inter.net...
The phosphors of any CRT will glow with a bit if UV radiation. Even
though the CRT is in the dark to your eyes, there may be enough UV
radiation from somewhere to make it glow. UV light is actually
invisible to the eyes. If you look directly in to a UV source (bad to
do), you will some blue glow because of the sub harmonics in the UV
source.

Being of phosphorescence, the phosphors on a CRT will easily glow in a
very dark environment. I have a watch with phosphor coated hands. They
glow in the dark for the whole night, and they are not radio active from
what I was told by the manufacture. And, there is no battery in the
watch. It is a windup one.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
==============================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
==============================================
"Steve Reinis" <noemail@all.com> wrote in message
news:bjr73c01qs4@enews4.newsguy.com...
I have this lightbox from a Projection TV. It's an RCA PTK195 chassis.
It's a spare that I bought on the cheap and it's been sitting in my
closet
for when the day comes I need parts for my working 52" RCA set.

The other night the power went out and I was fumbling around in the
closet
grasping for a flashlight. I noticed this very dim green glow in the
dark
down on the floor and couldn't figure out what is was until I realized
it
was coming from the green CRT in the ligthtbox.

Whoa... Weird... This lightbox has been in the closet, which is pitch
black, for many months now. No power had been applied to it recently,
no
exposure to light or anything that would make a CRT emit a soft glow.
(at
least, anything that I know of)

It's still glowing two night later!! Albeit, it's extremely dim, you
can
see the green CRT glowing by itself! I know a bit about electronics and
do
know the basics of how a CRT works, but this puzzles me! The red and
blue
CRTs are totally dark and as stated, the set has not been powered up or
exposed to any sources of light.

Three nights now I've noticed it glowing by itself. How is this
possible???

-Steve
Click to expand...
 
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