Green to black and white CRT

Thread Starter

Bobes

Joined Mar 19, 2020
51
Hello!
I got B13S8 oscilloscope CRT screen, and I want to build something like video monitor with it. But it has got green-coloured screen. Is there any option, for example some glass, what makes it look black and white? I know, that some glasses were made back in the 1950s for black and white screens to be "coloured", like this https://i.pinimg.com/originals/02/33/6c/02336c648443f1012b2c611e0779fcd6.jpg. As you can see there: http://danyk.cz/elmon2_en.html, the green CRT is not very nice to look at. Maybe, it is not electronic question, but thank you for your advices!
 

DickCappels

Joined Aug 21, 2008
6,533
The problem is that the only wavelength made by the phosphor is in the region seen by most people as green. With optical filtering you might make it look like it has a tinge of yellow in it but there is no blue with which to make white.
 

Thread Starter

Bobes

Joined Mar 19, 2020
51
So there is no option to do it? Some glass, what you put before the screen, andd from the other side you see it as Black?
 

Thread Starter

Bobes

Joined Mar 19, 2020
51
No, I don't hate Green colour . But when you want to Look at some pictures, and are Green, it doesn't Look good at All. Therefore, Black and White TVs were made instead of the Green ones.
 

DickCappels

Joined Aug 21, 2008
6,533
Or to give blue and Red glass, like this https://www.quora.com/What-two-colors-make-the-color-white? Sorry, if that is stupid question.

In terms of CRT phosphors (this varies a little depending upon the particular mixture and how warm or cold white is) There is a lot of green, almost as much red, and a little bit of blue. Since there is no blue to speak of in the green phosphors you get Red + Green = Yellow or some version of it at best.

Green phosphors were (are?) used on oscilloscopes because they did not need as much power to make a bright trace. That mean less beam current and that made holding the spot size small easier. Not that anybody really liked green, it just made a better looking and easier to read trace.
 

Thread Starter

Bobes

Joined Mar 19, 2020
51
Yes, I know the reason, why it is used to oscilloscope, but when I want it to use to Display some pictures, it bassicaly doesn't Look good, I think.
 

MisterBill2

Joined Jan 23, 2018
6,727
A green CRT in a scope will only produce green light. You might possibly find a B/W crt that could replace the scope CRT, but why bother? I once used an older yellow computer monitor to check the operation of a VCR. It was adequate to verify when the recording started past the ads. But it did amuse the folks around me.
 

DickCappels

Joined Aug 21, 2008
6,533
One method that comes to mind is unthinkably clumsy and awkward but if you image the green scope screen onto a color camera then eliminate the color subcarrier is composite video systems, reduce the chrominance (same thing) in component systems or redirect green to red, green and blue in the correct proportions you can get a video signal that you can display on a color receiver that will give you white of any color temperature you want. The gamma may be terribly wrong, but it will not be green. My best advice: don't consider it.
 

MisterBill2

Joined Jan 23, 2018
6,727
OK, I will have to be satisfied with Green picture :). A moment ago, I added New forum thread https://forum.allaboutcircuits.com/threads/simple-circuit-to-power-up-b13s8.169040/ feel free to reply. Thank you.
Changing the phosphor color on a CRT is a big deal operation. But there may actually be CRTs of the 5 inch electrostatic deflection type with other phosphors.
Of course I am not familiar with the B13S8 oscilloscope screen. Is that a whole scope, or just a display, or what? Now I am wondering.
 
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