Using brighteners?

[mattdavala]

Good day everybody!

I know back in the day people use to use brighteners on there weak CRT's. Well how effective was it? I have a 1955 Majestic 21inch console that is getting weak. It takes a few minutes for full brightness, which isn't much. Brightness is set about 90-95% full. Retrace lines too.

Would a brightener help before I can afford a rebuild(hah!) or would it destroy the heater? Check out the photo I have.

Does that look like a weak CRT to you? 21EP4B is what I have and its already a rebuild. Origional was a 21ZP4, this looks like the same tube but the gun in the CRT has handwritten on actual structure 21EP4B.

If a brightener would work does anyone have one theyd be will to give up?
Thanks!