This article starts with a brief description of historical observations that have been made concerning the effects of solar eclipses on the strengths of distant medium wave signals. It continues with a description of how medium-wave DXers used software defined radios (SDRs) for the first time during the solar eclipse of August 2017 to record the entire AM broadcast band (535-1705kHz) for later analysis. Although no plan had been made to create a formal experiment, it appears to be possible to use the data collected to analyze the effect of the eclipse on radio propagation. An example is presented, derived from recordings made at four different receiver locations in western North America, describing large variations in the signal strength from Salt Lake City's KSL-1160kHz during the course of the eclipse. The times that peak signal strengths occurred at the four locations are then compared relative to the times of eclipse totality along the signal paths.
HamSCI will again be at the Dayton Hamvention as part of the new Ham Radio 2.0: Innovation and Discovery area sponsored by the Yasme Foundation. Come visit the HamSCI Booth and Forum to learn about projects on the cutting edge of ham radio science and engineering research, including new directions in Sporadic E research, causes of F region ionospheric variability, how propagation works on the new 630 and 2200 m bands, the Personal Space Weather Station, and more. Hamvention will be held May 17-19, 2019 at the Greene County Fairgrounds in Xenia, Ohio.
Congratulations to the Case Amateur Radio Club for their second place score (out of 114 entries nation-wide) in the ARRL’s Frequency Measurement Test! The hosts of this year’s HamSCI workshop, W8EDU was able to measure the frequency of one 80 meter and one 40 meter transmission from K5CM to 0.03 and 0.02 Hertz, respectively. First place station W4VU in North Carolina won by only a slight margin of 0.01 Hz on 80 meters (a difference of one part per billion in the measurement).