[setquk]

Amateur here is "unpaid". Usually the obsessive nature of engineers, me included, means they tend to take the work home with them. Back when I was working for a defence contractor years and years ago there were a lot of amateur radio operators working on RF systems that had so much fun they went home and did another day's work there. Sometimes this was leveraged for personal gain and sometimes it actually played out and ended up in commercial radio systems. Similar to how a lot of people go home and write code. "Amateur programmers"