Ions and ion traps

[compucat]

Originally Posted by bandersen

I've read that electrostatic fields deflect the ions along with the electrons. So the ions are spread evenly over the screen rather than bombarding a circle in the middle. Eventually the screens do get dimmer but it takes a while.

Maybe that explains why older electrostatic tubes are not as bright as ones that are new old stock. I have a NOS 8BP4 for my Motorola 9VT1 that I have never tested as I am saving it until I really need it. I wonder how much brighter it would be compared to the one in my daily use set that was installed in 1954. Apparently the original CRT only lasted five years.