A Little Flat Tube Fun

[Telecolor 3007]

But how in the world they made the deflection when the gun was underneath?

[jr_tech]

Originally Posted by Telecolor 3007

But how in the world they made the deflection when the gun was underneath?

Electron beams can be deflected at 90 degrees or more. It is possible even to make a mirror which can reverse the travel of the beam completely. However, as the beam is deflected more the beam can be de-focused and geometry can suffer. The Sony tvs had considerable keystone correction, and yet the geometry was not very good on these tiny sets.

jr

[Electronic M]

Originally Posted by Telecolor 3007

But how in the world they made the deflection when the gun was underneath?

The screen is the back piece of glass. You look through one sheet of glass, through the vacuum then at the screen on the inside of the back wall of the CRT the screen curves gently out toward the viewer at the top. From the electron gun's perspective it it shooting at a very short wide screen....No crazy deflection angles here.

If you had asked a few months back I'd have given you a working Sony paddle CRT set for the cost of shipping.

[jr_tech]

Originally Posted by Electronic M

The screen is the back piece of glass. You look through one sheet of glass, through the vacuum then at the screen on the inside of the back wall of the CRT the screen curves gently out toward the viewer at the top. From the electron gun's perspective it it shooting at a very short wide screen....No crazy deflection angles here.

That is indeed true for the second generation design, the curved phosphor screen allowed the electron beam to land with only modest vertical deflection required. Magnetic deflection was employed for both axes.
The first generation design employed a flat phosphor screen at 90 degrees to the electron gun. A combination of magnetic and electrostatic deflection was used to achieve proper landing of the beam.

http://www.videokarma.org/attachment...5&d=1256418738

jr