Actually, the closest available MOSET to the IRF510
is the IRF512, which is the same device, only it is rated
for a drain voltage of 100v. It goes by other numbers as well.
There are many devices which are on a par with the IRF510.
such as the IRFZ10 and the BUZ20. Fairchild is a major
manufacturer. Try looking for MOSFETS with about the same
drain voltage or better, low R(ds) on, and relatively low gate
capacitance. It is the gate capacitance which makes the
real difference for a multi-band device. The IARF520 is ok;
it can be adapted; but there are others which are better.
Mind you, none of these include any RF devices. The real
reason they are used is because they can be adapted to RF,
and they are much cheaper than the RD16XXXX devices.
AFAIK, most of the RD05/15/16XXXX devices are still being
made, and the Hitachi devices are still readily available. That
may change tomorrow...
john
AD5YE
