"Michael Black" wrote in message
...

Nowadays, MOSFETs for RF are relatively uncommon.

That would be news to manufacturers of broadcast transmitters.

I think that you'll find that the usual solid state AM transmitter is a huge
D-to-A converter consisting of lots of MOSFETS. The 50-kW Harris DX-50 uses
that technique and is just about the "standard" 50-kW rig. It is used by
many stations. The transistors are in modules that can be hot-swapped while
the rig is on the air. Distortion is within limits even with a few of the
modules missing.

MOSFETs are also used as the output amplifiers in high power FM broadcast
100-MHz transmitters - certainly up to the 10-kW level.