Don I. Bailey, 9CS. QST, May 1921.

A hundred years ago this month, the May 1921 issue of Popular Mechanics carried a report of the ARRL Fading Tests of 1921.  In collaboration with the U.S. Bureau of Standards, hams took part in a citizen science experiment aimed at understanding the ionosphere.

During the tests, several stations, located in Chicago, Indianapolis, Hartford, New York City, and Washington, sent the letters of the alphabet, forward and backward, while participating stations noted the signal strength. This log was submitted by Don Bailey, 9CS, of Clinton, Iowa.