Thread: Build a TV?
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Old 9th Mar 2019, 3:41 pm   #3
Radio Wrangler
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Default Re: Build a TV?

Most scopes without PDAs and without aluminised screens ran at about 1.5 - 2.5kV cathode to screen. With that amount of acceleration and the current their cathodes could run, you got a reasonably bright scope trace.

But remember that a scope trace is only a 1-line picture.

Share that spot power over the whole screen area and the picture you get is very dim. Much higher total acceleration voltage is needed. Having the electrons going faster through the deflection area makes for very insensitive deflection electrostatic plate voltage swings would be problematical.

So go for a tube with 7-14kV on the final anode and magnetic deflection.

David
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