|The solar eclipse of Aug. 21, 2017 at totality.|
(Photo by Joe Eisenberg, K0NEB)
Dr. Phil Jackson, W1PJE, at MIT's Haystack Observatory, told the ARRL Letter that researchers there saw "a 2x reduction" in electron density for 45 minutes to an hour during the peak eclipse period.
The Letter also reported on a ham in Montana who said 20-meter propagation dropped to almost nothing during the eclipse but then recovered. Conversely, K1EHZ, in an article scheduled for the December issue of CQ, says propagation on the nighttime bands of 160 and 80 meters spiked during the eclipse and then returned to normal daytime levels.