RCA 21AXP22 picture tube/rebuilt picture tube

[miniman82]

The GP22 looks good to me, though the only real test is running it with a chassis. There's no risk involved, either you'll get a raster or a purple neck. What you need is high voltage to check for ionization, I ran my AXP on a CTC-9 chassis because the 4 chassis was still a long way off from being done.

Since you brought it up though, I do see a faint glow between the G1/G2 elements of a good tube under test so maybe it is normal. It's a different kind of glow though, the kind of color you see from beam tetrodes in operation- a more bluish hue.