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Name: John
Status: N/A
Age: 50s
Location: N/A
Country: N/A
Date: 1999 


Question:
I am a teacher of Advanced Chemistry and AP Chemistry for sophmores in HS. I would really like to show them a demonstration of a cathode ray, but our old CRT was from the '50s and my boss broke it. Can I make one, and if not, where can I buy a small one?


Replies:
what about just an old oscilloscope? You usually think that they can be controlled in the vertical direction -- this is how they are usually used. But many of them have inputs that allow control of the movement of the electron beam both in the horizontal and vertical directions. Many also have control of what they call the Z axis, that is, the intensity of the beam. Often this connection is on the rear of the scope. I have used scope's as TV displays, tho they look sort of fuzzy. But at least you can see how the voltage moves the beam of the electrons. You can also bring a magnet up to the face of the scope, and see how it distort things -- you could of course do this with any CRT, like your computer monitor, but it might mess things up so that you would have to de-gauss later.

A crt itself is an electron gun (tube) in a decent vacuum, hitting a phosphor screen. WHile all these pieces can be obtained, its not that easy, and it does need some reasonable voltage (100's of volts) to make the gun go. Maybe this would be a safety hazard unless you are careful.

S. Ross



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