An interesting (if useless) find

[Dave S]

Originally Posted by wkand

I am assuming that this tube has a metal cone and glass face, similar to the 15G. Also, that this seal would be the likely cause of going to air.

Correct?

Forgive me for not remembering, but would this tube be a possible rebuild candidate, if that ever happens at ETF?

John Folsom had said:

Originally Posted by John Folsom

The 15HP22 unfortunately has the same envelope construction as the 15GP22.

Therefore the big problem in dealing with the welded flange is the same on this tube.

The difference is the screen. The design of the 15G apparently makes it susceptible to problems during the rebuild process. According to miniman82, the mass of the screen inside the 15G makes the ramping of heat during the rebuild process a pretty ticklish affair. This tube has a conventional screen, so based on what I've heard from the experts, I'd guess the 15H would have a greater likelihood of a successful outcome. As long as the leak problem can be solved. Nick? Jerome? Bob? Steve? Please correct me if I'm wrong.

[miniman82]

Dave, I think that's correct. The internal design of the 15H shares more in common with the 19V and 21AX than it does with the 15G, though any rebuild attempt on any tube seems tenuous at best these days... I tell ya, these next 7 years can't go fast enough!