When I suggested using a vacuum tube based model it if course was in jest, but not surprised someone would actually doing that, I am impressed
As far as the output power of a tube model being too high that is a matter of how well it is designed, tubes are high energy devices (the voltage taken to excite them), but the power output is a function of the design and how many tubes are used and what type. If this was a commercial unit it is true that it would need to be certified under part 15 of FCC rules, but a home brew unit doesn't have to meet that. The person using this might screw up reception in their own house, but unless it was affecting people in other houses (unlikely) there is no law involved.
