Arv:
As Gordon points out, the grounded gate configuration applies to
the exciter, not to the final...a power MOSFET must have a gate voltage.
I wonder, since the gate capacitance is ca 180pF in the IRF510,
if one could apply a fixed bias, and use a capacitor with a varicap
in series to ground? That is done with smaller devices; it might work on
a power MOSFET. That would, in effect, vary the input impedance to some extent...
john
AD5YE
