In reply to bobcook39...@hotmail.com's message of Sat, 16 Jan 2021 20:23:48 +0000: Hi Bob,
BTW that may also explain the work of Alfred Hubbard and Bob Brown. Since they used AC current in their coils, which resulted in a constantly varying magnetic field which could have hit the right field strength at least twice per cycle (maybe 4 times if the polarity is irrelevant). If so, then the power output could be easily controlled by changing the frequency of the AC current in the coils, as that would vary the number of times per second that the right field strength was reached.