Jerry:
I wouldn't be so quick to defend the IRFxxx series.
Remember, these were designed to be switching
transistors working at about 500 KHz.
Yes, they can be adapted to RF with great success, but,
as Allison, Motorola, and WA2EBY discovered, layout is
critical as well as heat dispersion.
Most of the higher output amps involve more than one
device with large compensation for the input capacitance,
and a heavy heat sink.
Incidentally, the IRF610 gives much the same performance
as the IRF510, but it is rated to 100v instead of 70v. It is
an easy fix for more power.
john
AD5YE
