That's my next project as soon as I finish the PW exciter, a mosfet linear for 160-80-40... I imagine I'll go with just some sort of temp indicator or maybe a shut down circuit. You couldn't fold back the bias and still continue to operate, well, you could but you would no longer be linear, right?
Very cool. I was talking about FET bias temperature compensation.
I wondered if you plan to fold the bias back if the stage gets too hot.
I see the Fairchild FETs QIX found as a big brother to the 840s.
Imagine a big linear amplifier using them. fc