I run a couple of the QRP Labs on different bands and have found the output on say 80M and 160m were very good. More than 5 watts. In fact on 80m it will bury the needle on my Oaks Hills set on the 10 watt scale and run cool all night.
So my question is has anyone tried the 5 watt PA and U3S on 630m.
I fully realize that the big deal here will be antenna and matching for efficiency.