Re: ubitx - stop press
The IRF510 is really a general purpose device. I think initially it was chosen in a lot of projects when it came out due to it's low on-resistance. However it's not really a "rf device".
This guy made a decent 50watt amp for the IRF510.
A Simple Cheap 50 Watt PA
However this one uses true RF devices. Which I think is a much better approach. I haven't looked at the devices themselves closely to see if they could be substituted with the IRF510 or not directly. I was simply looking for a rf device that could be used for a new design. I just happened to see this discussion and share what information I have so far.
G6LBQ - HF LINEAR AMPLIFIER
So maybe someone can expand the research.