Build a Cathode Ray Tube - Experiment & Reference Guide

[edo1493]

I would like to build a cathode ray tube like this one: http://www.youtube.com/watch?v=XU8nMKkzbT8". It would be pretty damn cool playing with electrons.
Do you know any references about this experiment?
I mean, How could I build a glass vail and are there standard measures?

 

[edo1493]

Any advice?
Is there anybody who has already tried this experiment?

 

[fatra2]

Hi there,

Any advice?
Is there anybody who has already tried this experiment?

Practically everyday! Ok, I still have the old style TV (no flat screen or anything). This is precisely what happens in these old devices.

So if you want to "play" around with a CRT, just pick up an old TV or PC monitor from the dump. Strip it apart, and you will be left with a cathode ray.

Cheers

 

[cragar]

I actually tried to build one like 4 months ago , I took apart a tv but you can't see in the tube , so i broke off the back and got the filament out of it , and instead of a glass case, i made one out of pvc pipe with clear lexan windows . And i still had the wires hooked up to the tv connectors , and then i put a valve in it and tried to pump out the air but putting a hose from my pvc pipe to the intake valve on he compressor. Any ways after all of this it didn't work , I probably didn't have good enough vacuum . So i tried to make my own filament by cutting apart a oven burner and getting the wire out of it . I think it is a Tungsten molybdenum blend but not sure, any ways we are looking for a metal that we can heat up with like 12 volts so we can have a heated cathode and get thermionic emission . I have yet to try this but i will say making an electron gun from scratch is difficult and you have to have a good vacuum.

 

[edo1493]

The vacuum shouldn't be a problem, you need to buy a vacuum pump. I am afraid of the glass vail, If I want to take part in this project I will need a glass worker, cause it's not easy to find a perfect glass vail like the one in the video...

I don't understand the anode and the cathode, are they metal plates connected with wires ?

 

[cragar]

The electrons will be pushed off the cathode (negative) and attracted to the anode(positive) by the electric field , And you will supply a voltage between the plates.
Your basically having electrons flow between a parallel plate capacitor . look up
Thermionic emission , Instead of glass you might be able to use a Lexan (polycarbonate)
clear plastic housing.

 

[edo1493]

It could be an alternative, thanks! I don't think that glass is so comfortable..
What about the phosphor screen? I didn't understand how it works..

 

[cragar]

When an electron strikes the phosphor coating it excites it and light is released.

 

[edo1493]

I have talked about it at school with my chemistry teacher; she sad I could use many kinds of gas for the screen. I am still wondering Where I can find phosphor in a gas form. :P

 

[cragar]

what kind of colors are you wanting to make .

 

[edo1493]

I think that green is perfect. On the other hand I don't think that I will find a phosphor screen at the supermarket .

 

[Drakkith]

Just a word of safety, be VERY careful when you are playing around with this equipment. There is plenty of danger from electricity if you do not take the right precautions. The TV has high voltage that can injure or kill you, even if it is unplugged. Read up on and follow any high voltage safety rules you can get. A simple google search will yield some. And i also recommend going to a bookstore and buying anything you can find on basic electricity and electrical safety if you are not familiar with them.