[Amps] Negative current with a zener screen grid regulator

[Steve Wright]

On 19/10/16 05:00, N1BUG <paul at n1bug.com> wrote:
> [....] I ran this amp for many years with
> negative screen current and it obviously worked. But now that I'm
> having problems with it I want to understand things better.

My understanding is, part way through a tetrodes' life it's screen 
current requirements will reverse.

I think you could just swamp it with more current through the zener 
string, or else build an active MOSFET reg.


Steve