Many resonant frequencies of the MAHG have been postulated including 1.42 and 5.68 GHz. Moller's logbook says the tube is tuned to 2.4 GHz. But there is one more, the gap between the cathode and anode is 9.5 mm whose resonant frequency (full wave) would be 3.16 GHz.
I hope Jean-Louis is warming up his spectrum analyzer. :-)
