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Motorola 9" Black and White TV smell

A proper green phosphor can be excited by a pwm signal to display red.

A few very old black and white cathodes used a silver phosphor which when excited by the correct pwm signal would turn blue.
But full color I doubt, each phosphor has its own distinct energy states, it’s unlikely that one would emit all visible colors since the energy states likely jump to far in the frequency spectrum

Certain Thermometers use that effect to measure temperature .
 
AdamAnt316 said:
Here's the best image I'm aware of which demonstrates the issue with using a color wheel:
View attachment 50692
(unfortunately, I'm not aware of a larger version of said image)

That's Allen B. Dumont standing between an example of his company's mighty Royal Sovereign television set, and a 'dimensional model' of how large a color wheel would have to be in order to work properly with its 30" CRT (AFAIK, the largest direct-view television CRT until well into the color era). CBS countered with a prototype of a 17" CRT set using a color drum instead of a wheel (visible halfway down this page) which is much more reasonable in size. I believe they were also working on fully electronic sets which worked on the field sequential principle, but the signal wouldn't have been compatible with regular black & white sets of the day, which was the system's downfall (along with RCA's industry clout, anyway).
-Adam
Click to expand...

I wonder if a modern implementation could be done with a clear LCD panel in front of a B&W image and do the color rotation between red, green and blue. It'd eliminate the spinning wheel of death and the noise of the motor and spinning wheel, which were incredibly loud.
 
I believe that there's at least one YT video demonstrating this.

Our first TV was a Philco 10" "tabletop" model. Very heavy beast; we had the optional stand for it.

Were there any 2-color TV systems? Motion pictures certainly had two-color schemes.
 
I have a book describing a CRT without blue phosphors, and only two guns. But it was published during the war, and I think it might have been something that didn't make it to mass production.
 
Can you provide the title? Some white phosphors will "ghost" if you will blue effects, common on the PS/2 model 25 as been discussed. I really don't have a clue what the guy was talking about who I used to work with, I wish I'd pressed him for info. But apparently color effects can be obtained from white phosphors.
 
rmay635703 said:
A proper green phosphor can be excited by a pwm signal to display red.

A few very old black and white cathodes used a silver phosphor which when excited by the correct pwm signal would turn blue.
But full color I doubt, each phosphor has its own distinct energy states, it’s unlikely that one would emit all visible colors since the energy states likely jump to far in the frequency spectrum

Certain Thermometers use that effect to measure temperature .
Click to expand...

Vindication!
 
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GiGaBiTe said:
I wonder if a modern implementation could be done with a clear LCD panel in front of a B&W image and do the color rotation between red, green and blue. It'd eliminate the spinning wheel of death and the noise of the motor and spinning wheel, which were incredibly loud.
Click to expand...
I believe something along those lines was used to make the 3-D Glasses for the Sega Master System game console work. Nintendo made something similar (albeit released only in Japan) as the Famicom 3D System. Probably not nearly as sophisticated as what you're suggesting, but probably not too far off; more info about how both devices work can be found here. I have an example of the Sega 3D Glasses, though I have yet to try them out with my Master System.
-Adam
 
Chuck(G) said:
I believe that there's at least one YT video demonstrating this.

Our first TV was a Philco 10" "tabletop" model. Very heavy beast; we had the optional stand for it.

Were there any 2-color TV systems? Motion pictures certainly had two-color schemes.
Click to expand...

I often wondered why cyan orange duachrome was never a thing but I’m guessing the cost of having a color mask is the same whether it’s 2 or 3 color so no point in it.
PWMing circuitry to make the green phosphor with red afterglow stay red would likely not be cost effective either
 
inotarobot said:
You lot are UNbeleiveable DUMB not to know the 'ORRECT' answer

its the Black and White TV's electronics working overtime to become a COLOR TV so that it does not get thrown to the eScrapper.

Simply Falter its the smell of hot #eSweat without the blood.
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Sorry Falter seems my simple Aussie humor statement above has other 'hijacking' your original post on the smell, and turning it into a discussion on how early BW tv's actually showed color.
 
Not a problem. I'm enjoying reading about all this. I had not heard of color wheels until now!

As an aside, I have run the TV for several hours. The smell is not changing or going away but not getting worse. I'm thinking about taking it apart.. just nervous about breaking things.
 
Basically, what else is there to be said? That's why I veered off topic--the bad smell issue seems to have been diagnosed. Might as well add a bit of history... :)
 
falter said:
Not a problem. I'm enjoying reading about all this. I had not heard of color wheels until now!

As an aside, I have run the TV for several hours. The smell is not changing or going away but not getting worse. I'm thinking about taking it apart.. just nervous about breaking things.
Click to expand...

Got a shop vac? Why not try blowing the dust out? You shouldn't have to open it for that.
 
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