Tweet
I've read instructions for designing pentode gain stages (6SJ7, EF86), but one thing that confuses me is what exactly happens, performance-wise, as you vary the screen voltage, while all other parameters (plate and cathode resistors, supply voltage) remain the same.
I understand that the screen grid is essentially a second control grid and that, among other things, it has a lot to do with setting the operating points. In practice, I've seen 6SJ7 screen voltages range from 25% to 80% of the plate voltage. Why would a designer pick one over the other?
Or if there's a reference someone could point me to that would help me understand dynamic pentode behavior better, that would be great, too.
I understand that the screen grid is essentially a second control grid and that, among other things, it has a lot to do with setting the operating points. In practice, I've seen 6SJ7 screen voltages range from 25% to 80% of the plate voltage. Why would a designer pick one over the other?
Or if there's a reference someone could point me to that would help me understand dynamic pentode behavior better, that would be great, too.
Comment