gl sez:" But, the signal came through for only a few seconds, just 18 minutes after local sunset in Indiana with "grey line propagation." As the world turned, the sunset line moved and the signal went away."
Yup, I'm glad you picked up on that. The same thing would have been happening during an early evening listening period in Florida. The example in the link shows that it is possible, in rare occasions, to pick up a signal at very low power from great distances, for a short span of time, when conditions are just right. That's why I find Betty's notebook entries interesting, but not materially helping solve the mystery of AE's disappearance. They were unlikely (but not impossible) to have been received for more than a minute or two, and very, very unlikely (but not impossible) to have been received for hours, even fading in and out! I've spent some time trying to make sense of Betty's entries, but cannot find anything that is useful to solve the mystery. I won't throw it out as a potential clue, but it isn't necessary to support the hypothesis that AE landed somewhere in the Phoenix group and was able to transmit for a few days afterwards - the record of DF'd signals by professional operators provides enough data to form the hypothesis, and does not need Betty's notebook.