Gain stage with g2-feedback.

[Merlinb]

I ask myself, what is the use of that BJT in between the mosfet and the screen

It turns the pentode into a sort of hybrid cascode. Supposedly to eliminate partition noise, but then why not use a normal cascode...
Espacenet – search results

 

[Ketje]

It turns the pentode into a sort of hybrid cascode. Supposedly to eliminate partition noise, but then why not use a normal cascode...
Espacenet – search results

Yes I know, but why not connect the source to the screen.What is the use of the BJT in between, the mosfet does the same thing.
Mona