As per subject. My other old CRTs go dim but all the trinitron ones go
green. Is there a simple explanation?

Cheers,

h

In article ,
h wrote:
As per subject. My other old CRTs go dim but all the trinitron ones go
green. Is there a simple explanation?

It's not just Trintrons - pretty well all decent CRTs do this. At one time
to get a pure red the phosphor used was less sensitive than the others, so
that gun was driven the hardest. So aged first - resulting in the green
tint.

Later CRTs used a more 'orange' red which was more efficient and didn't
exhibit this fault. But wasn't as good as the original when new.

--
*There are two kinds of pedestrians... the quick and the dead.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message ...
In article ,
h wrote:
As per subject. My other old CRTs go dim but all the trinitron ones go
green. Is there a simple explanation?

It's not just Trintrons - pretty well all decent CRTs do this. At one time
to get a pure red the phosphor used was less sensitive than the others, so
that gun was driven the hardest. So aged first - resulting in the green
tint.

Later CRTs used a more 'orange' red which was more efficient and didn't
exhibit this fault. But wasn't as good as the original when new.

That's for sure. Anyone remember Zenith's FTM1490?
Just stunning red.

In article . net,
EDM wrote:
Later CRTs used a more 'orange' red which was more efficient and didn't
exhibit this fault. But wasn't as good as the original when new.

That's for sure. Anyone remember Zenith's FTM1490?
Just stunning red.

Yes. First generation PAL sets in the UK - dating from about '70 - were
capable of superb pictures when properly set up. Then the rot set in with
PIL tubes. They may have been consistent, but never as good as a decent
shadowmask.

I work in TV production, and think the grade 1 monitors used for camera
setup use the same NTSC phosphors as all those years ago...

--
*Very funny Scotty, now beam down my clothes.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article . net,
EDM wrote:
Later CRTs used a more 'orange' red which was more efficient and didn't
exhibit this fault. But wasn't as good as the original when new.

That's for sure. Anyone remember Zenith's FTM1490?
Just stunning red.

Yes. First generation PAL sets in the UK - dating from about '70 - were
capable of superb pictures when properly set up. Then the rot set in with
PIL tubes. They may have been consistent, but never as good as a decent
shadowmask.

I work in TV production, and think the grade 1 monitors used for camera
setup use the same NTSC phosphors as all those years ago...

--
*Very funny Scotty, now beam down my clothes.

Dave Plowman London SW
To e-mail, change noise into sound.

It sounds like you're speaking of the shadowmask in the past tense as if
modern CRTs don't use them anymore!

The 70s tubes were delta gun types and as I remember them, the convergence
(both static and dynamic) was downright evil to set up correctly. The PIL
tubes only need static convergence (if that!) and don't get mis aligned as
easily as the old delta gun tubes did, almost every delta gun set I ever
serviced needed convergence adjustment whilst this need became extremely
rare with the later PIL tubes.

h wrote:

As per subject. My other old CRTs go dim but all the trinitron ones go
green. Is there a simple explanation?

Cheers,

h


green does the least work.


--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

"Jamie" t wrote in message
...
h wrote:

As per subject. My other old CRTs go dim but all the trinitron ones go
green. Is there a simple explanation?

green does the least work.

Hmmm...

Trinitron is a single-gun tube. I would expect it to go dim rather than
having a color shift. If it goes green, maybe by losing the ability to
deflect the electron beam from stripe to stripe?

mc wrote:
"Jamie" t wrote in
message
...
h wrote:

As per subject. My other old CRTs go dim but all the trinitron
ones go
green. Is there a simple explanation?

green does the least work.

Hmmm...

Trinitron is a single-gun tube. I would expect it to go dim rather
than
having a color shift. If it goes green, maybe by losing the ability
to
deflect the electron beam from stripe to stripe?

1 gun in terms of G1,G2 but 3 separate cathodes that do indeed age at
different rates. I spotted a Sony PVM1354 at work today that is going
green and will need a new bottle shortly. Another common age symptom is
is highlight clipping of a single color, often red. It resembles a
'puddle' of the bad color. Only cure is to replace the tube.

GG

Cool, thanks for the answers. Always wondered, seems obvious when you hear
the explanation.

Cheers,

h

Dave Plowman (News) wrote:
In article ,
h wrote:

As per subject. My other old CRTs go dim but all the trinitron ones go
green. Is there a simple explanation?


It's not just Trintrons - pretty well all decent CRTs do this. At one time
to get a pure red the phosphor used was less sensitive than the others, so
that gun was driven the hardest. So aged first - resulting in the green
tint.

Later CRTs used a more 'orange' red which was more efficient and didn't
exhibit this fault. But wasn't as good as the original when new.



They haven't used the old fluorgermanate red phosphor in decades, early
60's or so? I've never actually seen a CRT that used it, everything in
my lifetime has been the newer orangish vanadate phosphor.

h wrote:
As per subject. My other old CRTs go dim but all the trinitron ones go
green. Is there a simple explanation?

Cheers,

h




The green phosphor tends to be the most efficient, if you've ever seen a
green fluorescent tube you'll see what I mean, the green is about 2x as
bright as the blue and many times brighter than the red.

In article 0VXyg.1721$8v.947@trnddc05,
James Sweet wrote:
Later CRTs used a more 'orange' red which was more efficient and didn't
exhibit this fault. But wasn't as good as the original when new.

They haven't used the old fluorgermanate red phosphor in decades, early
60's or so? I've never actually seen a CRT that used it, everything in
my lifetime has been the newer orangish vanadate phosphor.

Grade 1 monitors used to setup the pictures from broadcast cameras use a
much more 'red' phosphor than TV sets. Decent computer monitors for
graphics too. I dunno what it is, but they don't generally go so 'bright'
as domestic ones.

--
*Middle age is when work is a lot less fun - and fun a lot more work.

Dave Plowman London SW
To e-mail, change noise into sound.

"James Sweet" wrote in message
news:cXXyg.1723$8v.1366@trnddc05...
h wrote:
As per subject. My other old CRTs go dim but all the trinitron ones go
green. Is there a simple explanation?

Cheers,

h


The green phosphor tends to be the most efficient, if you've ever seen a
green fluorescent tube you'll see what I mean, the green is about 2x as
bright as the blue and many times brighter than the red.

Either that or the human eye is most sensitive at the green wavelength.

ian field wrote:
"James Sweet" wrote in message
news:cXXyg.1723$8v.1366@trnddc05...

h wrote:

As per subject. My other old CRTs go dim but all the trinitron ones go
green. Is there a simple explanation?

Cheers,

h


The green phosphor tends to be the most efficient, if you've ever seen a
green fluorescent tube you'll see what I mean, the green is about 2x as
bright as the blue and many times brighter than the red.


Either that or the human eye is most sensitive at the green wavelength.



It is, that's the other part of the equation, but the lumen rating is
substantially higher for the green than even for white.

"James Sweet" wrote in message
news:7vbzg.2065$8v.233@trnddc05...
ian field wrote:
"James Sweet" wrote in message
news:cXXyg.1723$8v.1366@trnddc05...

h wrote:

As per subject. My other old CRTs go dim but all the trinitron ones go
green. Is there a simple explanation?

Cheers,

h


The green phosphor tends to be the most efficient, if you've ever seen a
green fluorescent tube you'll see what I mean, the green is about 2x as
bright as the blue and many times brighter than the red.


Either that or the human eye is most sensitive at the green wavelength.

It is, that's the other part of the equation, but the lumen rating is
substantially higher for the green than even for white.

Next you're going to tell us how green is brighter than white - which is
made up of red, green & blue......................

Next you're going to tell us how green is brighter than white - which is
made up of red, green & blue......................




Depends, if it's a modern trichromatic fluorescent tube then yes, it's
made up of red, green and blue phosphors mixed as appropriate to obtain
the desired color temperature however the red and blue phosphors are
less efficient than the green so the white tube does indeed produce
fewer lumens than a green one. If it's one of the older halphosphate
phosphors (CW, WW, CWX, WWX, D) then it's a single color phosphor and
the emission is much more broad though with an abundance of yellow at
least in the case of CW and WW.

Personally I like the 80 series trichromatic tubes, 850 is a nice cool
5000K white with 80+ CRI, 835 is a more neutral 3500K which is a bit
more pleasant for living spaces. CWX is a standard halphosphate with the
addition of a fluorogermanate phosphor which emits a true deep red which
pushes the CRI up to around 90 but the light looks a bit pink to me.
There's some other nice mixes out there but many are hard to find.

ian field wrote:

"James Sweet" wrote in message
news:cXXyg.1723$8v.1366@trnddc05...
h wrote:
As per subject. My other old CRTs go dim but all the trinitron ones go
green. Is there a simple explanation?

Cheers,

h


The green phosphor tends to be the most efficient, if you've ever seen a
green fluorescent tube you'll see what I mean, the green is about 2x as
bright as the blue and many times brighter than the red.

Either that or the human eye is most sensitive at the green wavelength.

Or there's something about the color modulation that, with aging
components, causes the signal to drift toward green. I have an LCD (3"
screen) color TV that is about 10 years old. When driven from a
composite video input (from a DVD player) it looks fine. But the
broadcast signals are starting to look a bit green.

--
Paul Hovnanian
------------------------------------------------------------------
Stupidity kills. But not nearly often enough.

"Paul Hovnanian P.E." wrote in message
...
ian field wrote:

"James Sweet" wrote in message
news:cXXyg.1723$8v.1366@trnddc05...
h wrote:
As per subject. My other old CRTs go dim but all the trinitron ones go
green. Is there a simple explanation?

Cheers,

h


The green phosphor tends to be the most efficient, if you've ever seen
a
green fluorescent tube you'll see what I mean, the green is about 2x as
bright as the blue and many times brighter than the red.

Either that or the human eye is most sensitive at the green wavelength.

Or there's something about the color modulation that, with aging
components, causes the signal to drift toward green. I have an LCD (3"
screen) color TV that is about 10 years old. When driven from a
composite video input (from a DVD player) it looks fine. But the
broadcast signals are starting to look a bit green.

--
Paul Hovnanian
------------------------------------------------------------------
Stupidity kills. But not nearly often enough.

Not sure if NTSC works the same but the PAL system only recovers R-L & B-L
from the transmitted carrier, green is recovered by working out its
amplitude from the sum of the R & B signals subtracted from the luma signal.

Hmmm, just sort of in relation to this thread: can anyone tell me if
its worth repairing my Trinitron? Model: G420S.

The red is pretty much dead now, and the blue sometimes work and
sometimes doesn't. For the most part, the green is fine. Here's a video
of it a few months ago (it would flash during warming up but would
eventually stabilize, but the video shows it's totally crapping it...
turning it OFF then ON would fix this):

http://www.samaseysan.com/temporary/...experience.avi

wrote:
Hmmm, just sort of in relation to this thread: can anyone tell me if
its worth repairing my Trinitron? Model: G420S.

The red is pretty much dead now, and the blue sometimes work and
sometimes doesn't. For the most part, the green is fine. Here's a video
of it a few months ago (it would flash during warming up but would
eventually stabilize, but the video shows it's totally crapping it...
turning it OFF then ON would fix this):

http://www.samaseysan.com/temporary/...experience.avi



It's worth trying to resolder the neck board, that may be all it needs.

wrote:
Hmmm, just sort of in relation to this thread: can anyone tell me if
its worth repairing my Trinitron? Model: G420S.

The red is pretty much dead now, and the blue sometimes work and
sometimes doesn't. For the most part, the green is fine. Here's a video
of it a few months ago (it would flash during warming up but would
eventually stabilize, but the video shows it's totally crapping it...
turning it OFF then ON would fix this):

http://www.samaseysan.com/temporary/...experience.avi

resolder the crt neckboard area.
also change the rgb filter cap. maybe for good measure also change the
160v caps on the b+ line. I had to do this recently.on an E 200
trinitron
-B.

wrote:

mc wrote:
"Jamie" t wrote in
message
...
h wrote:

As per subject. My other old CRTs go dim but all the trinitron
ones go
green. Is there a simple explanation?

green does the least work.

Hmmm...

Trinitron is a single-gun tube. I would expect it to go dim rather
than
having a color shift. If it goes green, maybe by losing the ability
to
deflect the electron beam from stripe to stripe?

1 gun in terms of G1,G2 but 3 separate cathodes that do indeed age at
different rates. I spotted a Sony PVM1354 at work today that is going
green and will need a new bottle shortly. Another common age symptom is
is highlight clipping of a single color, often red. It resembles a
'puddle' of the bad color. Only cure is to replace the tube.

GG

Trinitrons suffer a lot from falling emission, and are easy to repair.
Boost the heater voltage, starting with +33%, and if not good enough go
to +50%. This is a permanent heater voltage boost. On no account use
those awful crt rejuvenator machines on these.

On an experimental set, in which none of the channels were even visible
indoors in daytime I used +70% heater boost and IIRC +10% EHT boost and
it survived and worked like that for years. EHT boost is not
recommended unless you know the tubes x-ray limits, and are willing to
accept a slight chance of it dying.


NT

wrote:
mc wrote:
"Jamie" t wrote in
message
...
h wrote:

As per subject. My other old CRTs go dim but all the trinitron
ones go
green. Is there a simple explanation?

green does the least work.

Hmmm...

Trinitron is a single-gun tube. I would expect it to go dim rather
than
having a color shift. If it goes green, maybe by losing the ability
to
deflect the electron beam from stripe to stripe?

1 gun in terms of G1,G2 but 3 separate cathodes that do indeed age at
different rates. I spotted a Sony PVM1354 at work today that is going
green and will need a new bottle shortly. Another common age symptom is
is highlight clipping of a single color, often red. It resembles a
'puddle' of the bad color. Only cure is to replace the tube.

GG


Trinitrons often suffer from falling emission but are easy to repair.
Apply +33% heater boost, and if this isnt enough apply +50%. This is
permament voltage boost, not a rejuve. Keep the rejuve machine well
away from them.

On an experimental set I used +70% heater boost (they ran yellow) and
IIRC +10% EHT boost. It ran fine that way for years, but you cant do
that sort of thing for other people. Dont boost EHT unless you know the
tube's x-ray limit rating, otherwise you can go over that sometimes.
When I got the set, none of the chanels were visible indoors in
daytime, and I fancied a challenge. I was very surprised the set
survived and worked, but it did, for years.


NT

b wrote:
wrote:
Hmmm, just sort of in relation to this thread: can anyone tell me if
its worth repairing my Trinitron? Model: G420S.

The red is pretty much dead now, and the blue sometimes work and
sometimes doesn't. For the most part, the green is fine. Here's a video
of it a few months ago (it would flash during warming up but would
eventually stabilize, but the video shows it's totally crapping it...
turning it OFF then ON would fix this):

http://www.samaseysan.com/temporary/...experience.avi

resolder the crt neckboard area.
also change the rgb filter cap. maybe for good measure also change the
160v caps on the b+ line. I had to do this recently.on an E 200
trinitron
-B.

I dunno how to do all that stuff. Is it dangerous? Easy? I don't even
have a solder, nor do I have any experience.

RGB wrote:
b wrote:

wrote:

Hmmm, just sort of in relation to this thread: can anyone tell me if
its worth repairing my Trinitron? Model: G420S.

The red is pretty much dead now, and the blue sometimes work and
sometimes doesn't. For the most part, the green is fine. Here's a video
of it a few months ago (it would flash during warming up but would
eventually stabilize, but the video shows it's totally crapping it...
turning it OFF then ON would fix this):

http://www.samaseysan.com/temporary/...experience.avi

resolder the crt neckboard area.
also change the rgb filter cap. maybe for good measure also change the
160v caps on the b+ line. I had to do this recently.on an E 200
trinitron
-B.


I dunno how to do all that stuff. Is it dangerous? Easy? I don't even
have a solder, nor do I have any experience.



Find someone who does, a TV is no place to learn the very basics.

RGB wrote:

I dunno how to do all that stuff. Is it dangerous? Easy? I don't even
have a solder, nor do I have any experience.

then keep out of TVs and microwaves.


NT