At one time, i was very interested in reading about this topic. I think i deserve some of the blame for the “harmonic reception” theory supporting stories of stateside reception of Earhart’s emergency messages, as i posted info about the transmitter to the TIGHAR group. At one time, i had the identical model to Earhart’s radio transmitter, and i was thinking, i would do some testing with a similar antenna and establish some actual numbers for power radiated on the harmonics of the two channels Earhart was equipped with. But – one person has only so much time, and so i passed the transmitter on to another person, who is doing a much better job investigating and reporting this story than i was.

The transmitter, as i recall, has W.E. power tubes with a “side cap” as well as a plate cap. Try to find spares for those !