One of the weekend morning news shows recently did a story on credible reports that numerous everyday Americans picked up Earhart distress calls days after she went missing with their shortwave radios. Apparently the atmospheric conditions bounced her signal all those thousands of miles.
Ham/SWL radio buffs will be very familiar with the tropical 90 meter band she used at night and the 49 meter band day.
In those days with many fewer signals crowding the bands, her 50 watt transmitter could propagate thousands of miles with the right conditions. That distance propagation is part of ham radio excitement.