Testing 7” Electrostatic CRT’s
 

I have a Sencore CR-70 and it does a pretty good job of testing Electrostatic CRT’s but sometimes it will show weak emission while the tube looks ok, other time’s it’ll show strong emissions and the tube will show a washed out picture, so here’s how I test them now.Super easy and shows the tubes true condition every time.

Testing NINE late 1940’s 7” CRT’s with a Motorola VT-71 Chassis
https://youtu.be/3kx-NJ5K0hA

Same method I use except I don't have a CR-70 so I have to use my Motorola chassis. Those electrostatic tubes lack ion traps AND aluminization so ion burn tends to degrage the whole screen and nothing short of a run on a working chassis will show the dimness caused by ion burn.