It’s for using TRX-DUO as signal generator.
I remember that I have old kit with IRF510. I bought it as assembled in 2019 year but received as a kit so I’ve just placed it in the dark corner 🙂
Now I think I can use it as 5w amplifier (or more output power with rd15hvf1).
With around 1dbm input I’m getting 1w output on 14m band.
It works. Post just for post 🙂