Hello,
I have lots of power mosfet (IRF640, 740, 840 and similars), I'd like
to try
to build a power amplifier for 50 MHz (even 100W CW is ok), what
parameters
of these mosfet can tell how high they can go in frequency? I've only
seen
some projects for HF bands with these kind of mosfets, so probably
there is
a good reason not to try to go higher. I think fall and rise time give
the
limit, but what else? Also, the datasheet of these devices don't have a
table of Zin and Zout, so how one is supposed to calculate them?
Thanks in advance for any hint.

73 de

IS0FKQ