I have a old thread here but no answer. I have yet to figure this out. I want to use a mosfet in an rf amplifier at 10 meters (yes I have a ham license) that will do about 120 watts or more per mosfet. I see irf510 units doing the job but only doing maybe 30-40 watts using two of them. How can I look at a spec sheet and figure out what the gain bandwidth is? Or for you specific people who twist the question and have no answer, It needs to be able to have at least 10 db of gain at 28 MHz . The voltage or current is of no concern to me. I need a mosfet or family of the mosfet that will do the job. I am looking for inexpensive types to use. What I need is an answer that will help me to calculate or be able to look at the specs and calculate. How much input capacitance am I looking at? I know how to calculate frequency using inductance and capacitance, but is that part of the equation in finding the proper one I need. I see it as maybe rise or fall time in the specs, lead inductance and capacitance, but there must be a more precise way of choosing. Transistors use ft bandwidth. mosfets can be figured out how?